Ch.14 - Chemical EquilibriumWorksheetSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

In order to calculate the equilibrium concentrations of compounds we need to use an ICE Chart. 

Calculating Equilibrium Concentrations

Concept #1: Understanding an ICE Chart 

An ICE Chart should be used when we are missing more than one equilibrium amount for compounds in our balanced equation. 

Since our equilibrium constant K is involved in an ICE Chart then we must continue to ignore solids and liquids. 

Example #1: We have a solution where Ag(CN)2 (g), CN (g), and Ag+ (g) have an equilibrium constant, K, equal to 1.8 x 10-19. If the equilibrium concentrations of Ag(CN)2 and CN are 0.030 and 0.10 respectively, what is the equilibrium concentration of Ag+?

Example #2: We place 2.5 mol of CO and 2.5 mol of CO3 in a 10.0 L flask and let the system come to equilibrium. What will be the final concentration of CO2?  K = 0.47

Practice: For the reaction: N2 (g) + 2 O2 (g) ⇌ 2 NO2 (g), Kc = 8.3 x 10 -10 at 25°C. What is the concentration of N2 gas at equilibrium when the concentration of NO2 is twice the concentration of O2 gas?

Example #3: When 0.600 atm of NO­­2 was allowed to come to equilibrium the total pressure was 0.875 atm. Calculate the Kof the reaction. 

Example #4: An important reaction in the formation of acid rain listed below.

2 SO2 (g)   +  O2 (g)  ⇌  2 SO3 (g)

Initially, 0.023 M SO2 and 0.015 M O2 are mixed and allowed to react in an evacuated flask at 340 oC. When an equilibrium is established the equilibrium amount of SO3 was found to be 0.00199 M. Calculate the equilibrium constant, Kc, for the reaction at 340 oC. 

Example #5: If Kc is 32.7 at 300oC for the reaction below:

H2 (g) +  Br2 (g) ⇌  2 HBr (g) 

What is the concentration of H2 at equilibrium if a 20.0 L flask contains 5.0 mol HBr initially?

Practice: At a given temperature the gas phase reaction: N2 (g) + O2 (g) ⇌ 2 NO (g) has an equilibrium constant of 4.00 x 10 -15. What will be the concentration of NO at equilibrium if 2.00 moles of nitrogen and 6.00 moles oxygen are allowed to come to equilibrium in a 2.0 L flask.

Example #6: Consider the following reaction:

COBr(g)  ⇌  CO (g) + Br(g)

A reaction mixture initially contains 0.15 M COBr2. Determine the equilibrium concentration of CO if Kc for the reaction at this temperature is 2.15 x 10-3.

Additional Problems
A hypothetical reaction is shown below. 2A(g) +B2(g) ↔ 2C(g). A flask of 1 L volume is charged with 0.382 mol A and 0.0952 mol of B2 and allowed to come to equilibrium. At equilibrium, the vessel is found to contain 0.0624 mol of C. What is the value of Kc for this reaction? A) 0.190 B. 1.79 C. 0.00193 D. 2.46 E. 0.596
At a certain temperature, 0.91 mol of NO is placed in a 1.0 L vessel. Once the equilibrium is established, 0.22 mol of each product is present. What is the Kc of the reaction? 2 NO (g) ⇌ N2 (g) + O2 (g) A. 0.22 B. 0.81 C. 1.2 D. 1.0
When excess PbCl2 is dissolved in 1.00 L of water, 0.032 mol of Cl − forms at equilibrium. What is the Kc of the reaction: PbCl2 (s) ⇌ Pb2+ (aq) + 2 Cl − (aq) Kc = ? A. 1.0x10−3 B. 1.3x10−4 C. 3.3x10−5 D. 1.6x10−5
Carbon monoxide gas reacts with hydrogen gas at elevated temperatures to form methanol according to this equation: CO (g) + 2 H2 (g) ⇌ CH3OH (g). When 0.4 moles of CO and 0.30 moles of hydrogen gas are allowed to reach equilibrium in a 1.0 L container, 0.05 moles of methanol are formed. What is the value of Kc? 0.50 3.57 1.7 5.4
1.75 moles of H2O2 were placed in a 2.50 L reaction chamber at 307ºC.  After equilibrium was reached, 1.20 moles of H2O2 remained.  Calculate the equilibrium constant, Kc, for the reaction 2 H2O2(g) ⇋ 2 H2O(g) + O2(g). A)  2.0 x 10–4    B)  2.3 x 10–2    C)  2.4 x 10–3    D)  5.5 x 10–3    E)  3.9 x 10–4
When heated at high temperatures, a diatomic vapor dissociates as follows: A2 (g) ⟺ 2A (g) In one experiment, a chemist finds that when 0.0520 mole A 2 was placed in a flask of volume 0.527 L at 590 K, the fraction of A2, dissociated was 0.0238.   a) Calculate Kc for the reaction at this temperature                   b) Calculate Kp for the reaction at this temperature    
Consider the hypothetical reaction A(g) 2B(g). A flask is charged with 0.76 atm of pure A, after which it is allowed to reach equilibrium at 0 oC. At equilibrium the partial pressure of A is 0.37 atm .What is the value of Kp?
Two different proteins X and Y are dissolved in aqueous solution at 37 oC. The proteins bind in a 1:1 ratio to form XY. A solution that is initially 1.00 m M in each protein is allowed to reach equilibrium. At equilibrium, 0.21 mM of free X and 0.21 mM of free Y remain.What is Kc for the reaction?
A chemist at a pharmaceutical company is measuring equilibrium constants for reactions in which drug candidate molecules bind to a protein involved in cancer. The drug molecules bind the protein in a 1:1 ratio to form a drug-protein complex. The protein concentration in aqueous solution at 25 oC is 1.72×10−6 M . Drug A is introduced into the protein solution at an initial concentration of 2.00 10-6 M. Drug B is introduced into a separate, identical protein solution at an initial concentration of 2.00 10-6 M. At equilibrium, the drug A-protein solution has an A-protein complex concentration of 1.00 10-6 M, and the drug B solution has a B-protein complex concentration of 1.40 10-6 M.Calculate the Kc value for the A-protein binding reaction.
Solve each of the expressions for x using the quadratic formula and the x is small approximation. In which of the following expressions is the x is small approximation valid?x2/(0.2 - x) = 1.3
Explain how you might deduce the equilibrium constant for a reaction in which you know the initial concentrations of the reactants and products and the equilibrium concentration of only one reactant or product.
Many equilibrium calculations involve finding the equilibrium concentrations of reactants and products given their initial concentrations and the equilibrium constant. Outline the general procedure used in solving these kinds of problems.
Consider the reaction shown below at 2200 °CN2 (g) + O2 (g) ↔ 2 NO (g)        K c = 0.0505A student adds 0.375 mol of N2 and 0.375 mol of O2 to a 2.50 L flask and then allows the reaction to come to equilibrium. What are the equilibrium concentrations of all reactants and products? 
The reaction NO2 (g)  +  NO (g)  ⇌   N2O (g)  +   O2 (g) reached equilibrium at a certain high temperature. Originally the reaction vessel contained the following initial concentrations: 0.184 M N2O, 0.377 M O2 , 0.0560 M NO2 and 0.294 M NO. The concentration of NO2 , the only colored gas in the mixture, was monitored by following the intensity of the color. At equilibrium, the NO2 concentration had become 0.118 M. What is the value of Kc for the reaction at this temperature? 
A flask is filled with sulfuryl chloride, SO2Cl2 and has an initial concentration of 0.168 M. If the flask is allowed to come to equilibrium according to the reaction shown below, what is the concentration of SO2 in the flask at equilibrium?SO2Cl2 (g) <==> SO2 (g) + Cl2 (g)   Kc = 2.32 x 10 -7A. 1.97 x 10-4 MB. 0.00851C. 3.90 x 10-8 MD. 4.39 x 10-4 ME. 1.62 x 10-4 M
Consider the following reaction:CH4 (g) + 2H2S (g) ↔ CS2 (g) + 4H2 (g)A reaction mixture initially contains 0.680 M CH 4 and 0.520 M H2S. When equilibrium is reached the concentration of H2 is determined to be 0.250 M. What equilibrium concentration of H 2S?a. 0.270 Mb. 0.583 Mc. 0.0200 Md. 0.395 Me. 0.458 M
The equation for the formation of hydrogen iodide from H 2 and I2 is:H2(g) + I2(g) ⇌ 2HI(g)The value of Kp for the reaction is 71 at 710.0 °C. What is the equilibrium partial pressure of HI in a sealed reaction vessel at 710.0 °C if the initial partial pressures of H2 and I2 are both 0.100 atm and initially there is no HI present?
At a certain temperature, A2 and B2 react to give AB as follows:A2 (g) + B2 (g) ⇌ 2 AB (g)                            K   c = 0.354If an 8.00 L flask initially contains 4.16 moles of A 2 and 4.16 moles of B2, find the equilibrium concentration of AB in the mixture.A. 0.142 MB. 0.175 MC. 0.119 MD. 1.91 ME. 0.238 M
A reaction mixture initially contains [N2O4] = 0.0250M. Find the equilibrium concentration of NO2.N2O4(g) ⇌ 2NO2(g)                                K   c = 0.36A) 0.054 MB) 0.140 MC) 0.005 MD) 0.041ME) 0.027 M
At a certain temperature, 0.0740 mol of PCl 5(g) were introduced into a one-liter container.PCl5(g) ⇋ PCl3(g) + Cl2(g)At equilibrium the concentration of PCl 3(g) was 0.0500 mol/L.a) What were the equilibrium concentrations of Cl 2(g) and PCl5(g)?   b) What is the value of Kc at the temperature of the experiment?
For the equilibrium, SO2(g) + NO2(g) ⇌ SO3(g) + NO(g) The four gases are mixed in a container in the following partial pressures (in atmospheres): SO 2 (2.3); NO2 (2.8); SO3 (1.4); and NO (3.4). At equilibrium it was found that the SO 2 partial pressure was 2.8 atmospheres, what is Kp? a) 0.28 b) 1.79 c) 2.87 d) 0.134 e) 3.54
At a certain temperature, the equilibrium constant, Kc, for this reaction is 53.3. H2(g) + I2(g) ⇌ 2HI(g) At this temperature, 0.400 mol of H2 and 0.400 mol of I2 were placed in a 1.00 L container to react. What concentration of HI is present at equilibrium?
Consider the following reaction:COCl2 (g) ⇌ CO (g) + Cl2 (g)A reaction mixture initially contains 1.6 M COCl 2. Determine the equilibrium concentration of CO if Kc for the reaction at this temperature is 8.33 x 10 -4. A) 4.2 x 10-4 MB) 1.5 x 10-3 MC) 3.7 x 10-2 MD) 2.1 x 10-2 ME) 1.3 x 10-3 M
A 5.0 L evacuated flask is charged with 2.0 moles of CO 2 and 1.5 moles of H 2 is allowed to come to equilibrium at 25 oC. If the equilibrium constant is 2.50, what is the equilibrium concentration of H2O?                               CO   2 (g)  +    H 2 (g)  ⇌  CO (g)  +  H 2O (g) 
A container initially contains [Br2] = 0.1 M and [I 2] = 0.2 M and undergoes the reaction:Br2 (g) + I 2 (g) ⇌ 2 BrI (g)     Kc = 1x10–10 at 25 °C:Calculate the equilibrium concentration of BrI(g).A) 1x10−3B) 3.5x 10−6C) 1.4x10−6D) 7.7 x 10−7E) 0.012 
At a certain temperature, the Kc of the reaction below is 1.5 x10 −11. If 0.10 mol N2 and 0.10 mol O2 are reacted together in a 1.00 L container, how much NO is present at equilibrium?N2 (g) + O2 (g) ⇌ 2 NO (g) Kc = 1.5x10−11A. 1.5x10−13 MB. 0.20 MC. 3.9x10−7 MD. 1.9x10−5 M
Carbon monoxide gas reacts with hydrogen gas at elevated temperatures to form methanol according to this equation.CO (g) + 2 H2 (g) ⇋ CH3OH (g)When 0.40 mol of CO and 0.30 mol of H 2 are allowed to reach equilibrium in a 1.0 L container, 0.060 mol of CH3OH are formed. What is the value of   Kc?a) 0.50b) 0.98c) 1.7d) 5.4 
Phosphorus pentachloride decomposes to phosphorus trichloride at high temperatures according to the equation: PCl5(g) ⇌ PCl3(g) + Cl2(g) At 250° 0.125 M PCl5 is added to the flask. If Kc = 1.80, what are the equilibrium concentrations of each gas?
Consider the reaction below:CaS (aq) + MgSO4 (aq) ↔ CaSO4 (s) + MgS (aq)If K is 20 and the initial concentrations of CaS, MgSO4 and MgS are 0.5 M, 0.6 M and 0 M respectively, what is the equilibrium concentration of MgSO4?1. 0.1 M2. 0.4 M3. 0.2 M4. 0 M
The system described by the reactionCO(g) + Cl2(g) ⇌ COCl2(g)is at equilibrium at a given temperature when  PCO =0.31 atm , PCl2 = 0.11 atm , and PCOCl2 = 0.59 atm. An additional pressure of Cl2(g) = 0.38 atm is added.Find the pressure of CO when the system returns to equilibrium.
A 1.000 L vessel is filled with 2.000 moles of N 2, 1.000 mole of H2, and 2.000 moles of NH3. N2 (g) + 3 H2 (g) ⇌ 2 NH3 (g)When the reaction comes to equilibrium, it is observed that the concentration of H2 is 2.34 moles/L. What is the numerical value of the equilibrium constant Kc?
Consider the following reaction:Fe3+(aq) + SCN-(aq) ⇌ FeSCN2+(aq)A solution is made containing an initial [Fe3+] of 1.1 x 10-3M an initial [SCN-] of 7.8 x 10-4M. At equilibrium, [FeSCN2+] = 1.7 x 10-4M.A) Kc = 2.0 x 102B) Kc = 3 x 10-2C) Kc = 3.3 x 10-3D) Kc = 3.0 x 102E) Kc = 5.0 x 10-3
Practice: Consider the famous ammonia preparation3 H2(g) + N2(g) ⇌ 2 NH3(g)The equationK = [x]2 / [0.1 − 3x]3 [0.7 − x]is not a possible correct description of the equilibrium situation because
A 2.00 liter vessel is filled with NH 3 (g) to a pressure of 4.00 atm and the reactionN2 (g) + 3 H2 (g) ⇌ 2 NH3 (g)comes to equilibrium at a fixed temperature. At equilibrium it is found that the pressure of H2 is 2.7 atm. What is the equilibrium pressure of NH3? 
The equilibrium constant for the reaction below at 25°C is 4.8 x 10 -6. Calculate the equilibrium concentration (mol/L) of Cl2 (g) if the initial concentration of ICI (g) is 1.33 mol/L. There is no I2 or Cl2 initially present. 2 ICI (g) ⇌ I2 (g) + Cl2 (g)a.) 2.9 x 10 -3b.) 5.8 x 10 -3c.) 3.2 x 10 -6d.) 6.4 x 10 -6e.) 343
What is the amount of "C" at equilibrium when 1 mole of A and 1 mole of B react according to the chemical reaction: 2 A + 2 B ⇌ C ?a. between 0 and 0.5 moleb. exactly 1 molec. between 0.5 and 2 molesd. exactly 2 molese. greater than two moles
If a 10.0 L vessel is charged with 0.482 mol N 2, 0.933 mol O2, calculate the concentration of each species at equilibrium.2 N2 + O2 ⇌ 2 N2O       Kc = 2.0 x 10 -32
For the exothermic reactionPCl3(g) + Cl2(g) ⇌ PCl5(g)     Kp = 0.180 at a certain temperature.A flask is charged with 0.500 atm PCl3, 0.500 atm Cl2, and 0.300 atm PCl5 at this temperature.What are the equilibrium partial pressures of PCl 3, Cl2, and PCl5, respectively?Express your answers numerically in atmospheres with three digits after the decimal point, separated by commas.
Carbon disulfide is prepared by heating sulfur and charcoal. The chemical equation isS2(g) + C(s) → CS2(g)          Kc = 9.40 at 900 KHow many grams of CS2(g) can be prepared by heating 11.1 moles of S2(g) with excess carbon in a 7.00 L reaction vessel held at 900 K until equilibrium is attained?
For the reaction: H 2 (g) + Br 2 (g) ⇌ 2 HBr (g), K c = 7.5 × 10 2 at a certain temperature. If 2 mole each of H 2 and Br 2 are placed in 2-L flask, what is the concentration of H 2 at equilibrium?   A) 0.96      B) 0.93            C) 1.86            D) 0.04            E) 0.07
Consider this reactionAB3(g) ⇌ A(g) + 3B(g) What is the equilibrium constant expression if the intial concentration of  AB3 is 0.1 M and the equilibrium concentration of A is represented by x? Assume the intial concentrations of A and B are both zero. 
A flask is filled with 1.08 atm of oxygen gas and 0.88 atm of ammonia and the following reaction is allowed to come to equilibrium in the closed container.4 NH3 (g) + 5 O 2 (g) <==> 4 NO (g) + 6 H 2O (g)At equilibrium the pressure of O 2 is determined to be 0.38 atm. Calculate the pressure H 2O at equilibrium.A. 0.140 atmB. 0.840 atmC. 2.28 atmD. 0.456 atmE. 3.50 atm
A mixture consisting of 0.250 M N2(g) and 0.500 M H2 (g) reaches equilibrium according to the equation N2(g) + 3 H2(g) → 2 NH3(g)At equilibrium, the concentration of ammonia is 0.150M. Calculate the concentration of H2(g) at equilibrium. 1. 0.350 M2. 0.150 M3. 0.425 M4. 0.275 M5. 0.0750 M 
A mixture of 1.00 atm of NO, 0.50 atm of H 2, and 1.00 atm of N2 was allowed to reach equilibrium according to the reaction given below (initially there was no H2O). At equilibrium, the partial pressure of NO was found to be 0.62 atm. Determine the value of the equilibrium constant, Kp, for the reaction: 2NO(g) + 2H2(g) ⇌ N2(g) + 2H2O(g) a) 6.08 b) 31.0 c) 215.0 d) 26.5 e) 651.0
Consider the following reaction at 425 KBr2 (g) + Cl2 (g) ⇌ 2 BrCl (g)    Kc = 5.81If a 5.00 L reaction vessel in initially charged with 4.65 moles of Br  2 and 4.65 moles of Cl2, determine the concentration of Cl2 at equilibrium.A. 0.422 MB. 2.11 MC. 0.691 MD. 1.69 ME. 0.508 M
The gas arsine, AsH3, decomposes as follows:2AsH3(g) ⇌ 2As(s) + 3H2(g)In an experiment at a certain temperature, pure AsH 3(g) was placed in an empty, rigid, sealed flask at a pressure of 392.0 torr. After 48 hours the pressure in the flask was observed to be constant at 488.0 torr.a. Calculate the equilibrium pressure of H 2(g).
At a certain temperature, K = 9.1 x 10 -4 for the reactionFeSCN2+(aq) ⇌ Fe3+(aq) + SCN -(aq)Calculate the concentrations of Fe3+, SCN -, and FeSCN2+ in a solution that is initially 2.0 M FeSCN2+.
Consider the reaction of A to form B: 2A(g) ⇌ B(g); Kc = 1.9 × 10−5 (at 298 K)A reaction mixture at 298 K initially contains [A] = 0.60 M. What is the concentration of B when the reaction reaches equilibrium?
In an analysis of interhalogen reactivity, 0.500 mol of ICl was placed in a 5.00-L flask, where it decomposed at a high T:2ICl(g) ⥫⥬ I2(g) + Cl2(g)Calculate the equilibrium concentrations of I2, Cl2, and ICl (Kc = 0.110 at this temperature).
For the following reaction at a certain temperatureH2(g) + F2(g) ⇌ 2HF(g)it is found that the equilibrium concentrations in a 5.00-L rigid container are [H 2] = 0.0500 M, [F2] = 0.0100 M, and [HF] = 0.400 M. If 0.200 mole of F2 is added to this equilibrium mixture, calculate the concentrations of all gases once equilibrium is reestablished.
The equilibrium constant for the reaction Hg2+(aq) + 2Cl−(aq) ⇌ HgCl2(aq) is 1.6 × 1013. Is HgCl2 a strong electrolyte or a weak electrolyte? What are the concentrations of Hg2+ and Cl– in a 0.015-M solution of HgCl2?
Assume that the change in concentration of N 2O4 is small enough to be neglected in the following problem.(a) Calculate the equilibrium concentration of both species in 1.00 L of a solution prepared from 0.129 mol of N2O4 with chloroform as the solvent.N2O4(g) ⇌ 2NO2(g)         Kc = 1.07 x 10−5 in chloroform
A key step in the extraction of iron from its ore is FeO(s) + CO(g) ⥫⥬ Fe(s) + CO2(g) Kp = 0.403 at 1000°C This step occurs in the 700°C to 1200°C zone within a blast furnace. What are the equilibrium partial pressures of CO(g) and CO2(g) when 1.00 atm of CO(g) and excess FeO(s) react in a sealed container at 1000°C?
Consider the following reaction: 2NO(g) + Br2(g) ⇌ 2NOBr(g) Kp= 28.4 at 298 K In a reaction mixture at equilibrium, the partial pressure of NO is 107 torr and that of Br2 is 166 torr. What is the partial pressure of NOBr in this mixture?  
For the reaction below, Kp = 1.16 at 800.ºC. CaCO3(s) ⇌ CaO(s) + CO2(g)If a 20.0-g sample of CaCO3 is put into a 10.0-L container and heated to 800.ºC, what percentage by mass of the CaCO3 will react to reach equilibrium?
Peptide decomposition is one of the key processes of digestion, where a peptide bond is broken into an acid group and an amine group. We can describe this reaction as follows:Peptide(aq) + H2O(l) ⇌ acid group(aq) + amine group(aq)If we place 1.0 mole of peptide into 1.0 L water, what will be the equilibrium concentrations of all species in this reaction? Assume the K value for this reaction is 3.1 x 10 -5.
The creation of shells by mollusk species is a fascinating process. By utilizing the  Ca2+ in their food and aqueous environment, as well as some complex equilibrium processes, a hard calcium carbonate shell can be produced. One important equilibrium reaction in this complex process is HCO3-(aq) ⇌ H +(aq) + CO32-(aq)                K = 5.6 x 10 -11If 0.16 mole of HCO3- is placed into 1.00 L of solution, what will be the equilibrium concentration of CO32-?
Methanol, a common laboratory solvent, poses a threat of blindness or death if consumed in sufficient amounts. Once in the body, the substance is oxidized to produce formaldehyde (embalming fluid) and eventually formic acid. Both of these substances are also toxic in varying levels. The equilibrium between methanol and formaldehyde can be described as follows:CH3OH(aq) ⇌ H2CO(aq) + H2(aq)Assuming the value of K for this reaction is 3.7 x 10 -10, what are the equilibrium concentrations of each species if you start with a 1.24 M solution of methanol? What will happen to the concentration of methanol as the formaldehyde is further converted to formic acid?
The reaction N2(g) + O2(g) ⇌ 2NO(g) is carried out at a temperature at which Kc = 0.060. The reaction mixture starts with only the product, [NO] = 0.0400 M, and no reactants. Find the equilibrium concentrations of N2 at equilibrium.
The reaction N2(g) + O2(g) ⇌ 2NO(g) is carried out at a temperature at which Kc = 0.060. The reaction mixture starts with only the product, [NO] = 0.0400 M, and no reactants. Find the equilibrium concentrations of O2 at equilibrium.
At a particular temperature, 8.1 moles of NO2 gas is placed in a 3.0-L container. Over time the NO2 decomposes to NO and O2:2NO2(g) ⇌ 2NO(g) + O2(g)At equilibrium the concentration of NO(g) was found to be 1.4 mol/L. Calculate the value of  K for this reaction.
The reaction N2(g) + O2(g) ⇌ 2NO(g) is carried out at a temperature at which Kc = 0.060. The reaction mixture starts with only the product, [NO] = 0.0400 M, and no reactants. Find the equilibrium concentrations of NO at equilibrium.
Consider the reaction for the decomposition of hydrogen disulfide: 2H2S(g) ⇌ 2H2(g) + S2(g), Kc = 1.67 x 10–7 at 800 oC. A 0.500 L reaction vessel initially contains 0.125 mol of H2S and 0.125 mol of H2 at 800 oC. Find the equilibrium concentration of [S2].
In a given experiment, 5.2 moles of pure NOCl was placed in an otherwise empty 2.0-L container. Equilibrium was established by the following reaction:2NOCl(g) ⇌ 2NO(g) + Cl2(g)                K = 1.6 x 10 -5b. Calculate the equilibrium concentrations for all species.
For the reaction N2O4(g) ⇌ 2NO2(g), Kp = 0.25 at a certain temperature. If 0.040 atm of N2O4 is reacted initially, calculate the equilibrium partial pressures of NO 2(g) and N2O4(g).
Consider the following reaction: I2(g) + Cl2(g) ⇌ 2ICl(g), Kp = 81.9 (at 25 oC)A reaction mixture at 25oC initially contains PI2 = 0.160 atm, PCl2 = 0.160 atm, and PICl = 0.00 atm. Find the equilibrium partial pressure of I2 at this temperature.
Consider the following reaction: I2(g) + Cl2(g) ⇌ 2ICl(g), Kp = 81.9 (at 25 oC)A reaction mixture at 25oC initially contains PI2 = 0.160 atm, PCl2 = 0.160 atm, and PICl = 0.00 atm. Find the equilibrium partial pressure of Cl2 at this temperature.
Consider the following reaction: I2(g) + Cl2(g) ⇌ 2ICl(g), Kp = 81.9 (at 25 oC)A reaction mixture at 25oC initially contains PI2 = 0.160 atm, PCl2 = 0.160 atm, and PICl = 0.00 atm. Find the equilibrium partial pressure of ICl at this temperature.
Assume that the change in concentration of COCl 2 is small enough to be neglected in the following problem.(a) Calculate the equilibrium concentration of all species in an equilibrium mixture that results from the decomposition of COCl2 with an initial concentration of 0.3166 M.COCl2(g) ⇌ CO(g) + Cl2(g)           K c = 2.2 × 10−10
Ammonium carbamate (NH2COONH4) is a salt of carbamic acid that is found in the blood and urine of mammals. At 250°C, Kc = 1.58 x 10−8 for the following equilibrium:   NH2COONH4(s) ⇌ 2NH3(g) + CO2(g) If 7.80 g of NH2COONH4 is put into a 0.500-L evacuated container, what is the total pressure at equilibrium?
Assume that the change in pressure of H 2S is small enough to be neglected in the following problem.(a) Calculate the equilibrium pressures of all species in an equilibrium mixture that results from the decomposition of H2S with an initial pressure of 0.824 atm.2H2S(g) ⇌ 2H2(g) + S2(g)               K P = 2.2 x 10 −6
The two most abundant atmospheric gases react to a tiny extent at 298 K in the presence of a catalyst:         N 2(g) + O2(g) ⥫⥬ 2NO(g)            K p = 4.35×10−31(a) What are the equilibrium pressures of the three gases when the atmospheric partial pressures of O2 (0.210 atm) and of N2 (0.780 atm) are put into an evacuated 1.00-L flask at 298 K with the catalyst?
In a study of synthetic fuels, 0.100 mol of CO and 0.100 mol of water vapor are added to a 20.00-L container at 900.°C, and they react to form CO2 and H2. At equilibrium, [CO] is 2.24×10−3 M. (a) Calculate Kc at this temperature. (b) Calculate Ptotal in the flask at equilibrium. (c) How many moles of CO must be added to double this pressure?
In a study of synthetic fuels, 0.100 mol of CO and 0.100 mol of water vapor are added to a 20.00-L container at 900.°C, and they react to form CO2 and H2. At equilibrium, [CO] is 2.24×10−3 M. (a) Calculate Kc at this temperature. (b) Calculate Ptotal in the flask at equilibrium. (c) How many moles of CO must be added to double this pressure?(d) After Ptotal is doubled and the system reattains equilibrium, what is [CO] eq?
An industrial chemist introduces 2.0 atm of H 2 and 2.0 atm of CO2 into a 1.00-L container at 25.0°C and then raises the temperature to 700°C, at which Kc = 0.534: H2(g) + CO2(g) ⇌ H2O(g) + CO(g) How many grams of H2 are present at equilibrium?
The two most abundant atmospheric gases react to a tiny extent at 298 K in the presence of a catalyst:         N 2(g) + O2(g) ⥫⥬ 2NO(g)            K p = 4.35×10−31 (a) What are the equilibrium pressures of the three gases when the atmospheric partial pressures of O2 (0.210 atm) and of N2 (0.780 atm)(b) What is Ptotal in the container?
For the reaction M2 + N2 ⥫⥬ 2MN, scene A represents the mixture at equilibrium, with M black and N orange. If each molecule represents 0.10 mol and the volume is 1.0 L, how many moles of each substance will be present in scene B when that mixture reaches equilibrium?
An initial mixture of nitrogen gas and hydrogen gas is reacted in a rigid container at a certain temperature by the reaction3H2(g) + N2(g) ⇌ 2NH3(g)At equilibrium, the concentrations are [H 2] = 5.0 M, [N 2] = 8.0 M, and [NH3] = 4.0 M. What were the concentrations of nitrogen gas and hydrogen gas that were reacted initially?
Nitrogen gas (N2) reacts with hydrogen gas (H2) to form ammonia (NH3). At 200ºC in a closed container, 1.00 atm of nitrogen gas is mixed with 2.00 atm of hydrogen gas. At equilibrium, the total pressure is 2.00 atm. Calculate the partial pressure of hydrogen gas at equilibrium, and calculate the Kp value for this reaction.
A mixture of 1.374 g of H2 and 70.31 g of Br2 is heated in a 2.00 L vessel at 700 K . These substances react as follows:H2(g) + Br2(g) 2HBr(g)At equilibrium the vessel is found to contain 0.566 g of H2.Calculate the equilibrium concentration of Br2.
A mixture of 1.374 g of H2 and 70.31 g of Br2 is heated in a 2.00 L vessel at 700 K . These substances react as follows:H2(g) + Br2(g) 2HBr(g)At equilibrium the vessel is found to contain 0.566 g of H2.Calculate the equilibrium concentration of HBr.
At a particular temperature, Kp = 0.25 for the reaction N2O4(g) ⇌ 2NO2(g)b. A flask containing only NO2 at an initial pressure of 9.0 atm is allowed to reach equilibrium. Calculate the equilibrium partial pressures of the gases.
A gaseous mixture of 10.0 volumes of CO 2, 1.00 volume of unreacted O 2, and 50.0 volumes of unreacted N2 leaves an engine at 4.0 atm and 800. K. Assuming that the mixture reaches equilibrium, what are the partial pressure?2CO2(g) ⥫⥬ 2CO(g) + O2(g)        Kp = 1.4×10−28 at 800. K(The actual concentration of CO in exhaust gas is much higher because the gases do not reach equilibrium in the short transit time through the engine and exhaust system.)
At 35ºC, K = 1.6 x 10 -5 for the reaction2NOCl(g) ⇌ 2NO(g) + Cl2(g)Calculate the concentrations of all species at equilibrium for each of the following original mixtures.a. 2.0 moles of pure NOCl in a 2.0-L flask
At 35ºC, K = 1.6 x 10 -5 for the reaction2NOCl(g) ⇌ 2NO(g) + Cl2(g)Calculate the concentrations of all species at equilibrium for each of the following original mixtures.b. 1.0 mole of NOCl and 1.0 mole of NO in a 1.0-L flask
At 35ºC, K = 1.6 x 10 -5 for the reaction2NOCl(g) ⇌ 2NO(g) + Cl2(g)Calculate the concentrations of all species at equilibrium for each of the following original mixtures.c. 2.0 moles of NOCl and 1.0 mole of Cl 2 in a 1.0-L flask
At a particular temperature, K = 4.0 x 10 -7 for the reactionN2O4(g) ⇌ 2NO2(g)In an experiment, 1.0 mole of N2O4 is placed in a 10.0-L vessel. Calculate the concentrations of N2O4 and NO2 when this reaction reaches equilibrium.
At a particular temperature, K = 2.0 x 10 -6 for the reaction2CO2(g) ⇌ 2CO(g) + O2(g)If 2.0 moles of CO2 is initially placed into a 5.0-L vessel, calculate the equilibrium concentrations of all species.
A gaseous mixture of 10.0 volumes of CO 2, 1.00 volume of unreacted O 2, and 50.0 volumes of unreacted N2 leaves an engine at 4.0 atm and 800. K. Assuming that the mixture reaches equilibrium, what are the concentration (in picograms per liter, pg/L) of CO in this exhaust gas?2CO2(g) ⥫⥬ 2CO(g) + O2(g)        Kp = 1.4×10−28 at 800. K(The actual concentration of CO in exhaust gas is much higher because the gases do not reach equilibrium in the short transit time through the engine and exhaust system.)
Lexan is a plastic used to make compact discs, eyeglass lenses, and bulletproof glass. One of the compounds used to make Lexan is phosgene (COCl2), an extremely poisonous gas. Phosgene decomposes by the reactionCOCl2(g) ⇌ CO(g) + Cl2(g)for which Kp = 6.8 x 10 -9 at 100ºC. If pure phosgene at an initial pressure of 1.0 atm decomposes, calculate the equilibrium pressures of all species.
At 25ºC, Kp = 2.9 x 10 -3 for the reactionNH4OCONH2(s) ⇌ 2NH3(g) + CO2(g)In an experiment carried out at 25ºC, a certain amount of NH4OCONH2 is placed in an evacuated rigid container and allowed to come to equilibrium. Calculate the total pressure in the container at equilibrium.
Calculate the pressures of all species at equilibrium in a mixture of NOCl, NO, and Cl 2 produced when a sample of NOCl with a pressure of 10.0 atm comes to equilibrium according to this reaction:2NOCl(g) ⇌ 2NO(g) + Cl 2(g)          K P = 4.0 x 10−4
Using CH4 and steam as a source of H2 for NH3 synthesis require high temperature. Rather than burning CH4 separately to heat the mixture, it is more efficient to inject some O 2 into the reaction mixture. All of the H2 is thus released for the synthesis, and the heat of reaction for the combustion of CH4 helps maintain the required temperature. Imagine the reaction occurring in two steps:2CH4(g) + O2(g) ⥫⥬ 2CO(g) + 4H2(g)    Kp = 9.34×1028 at 1000. KCO(g) + H2O(g) ⥫⥬ CO2(g) + H2(g)        Kp = 1.374 at 1000. K(d) A mixture of 2.0 mol of CH 4, 1.0 mol of O 2, and 2.0 mol of steam with a total pressure of 30. atm reacts at 1000. K at constant volume. Assuming that the reaction is complete and the ideal gas law is a valid approximation, what is the final pressure?
You are a member of a research team of chemists discussing plans for a plant to produce ammonia:   N2(g) + 3H2(g) ⇌ 2NH3(g) (b) One member of the team suggests the following: since the partial pressure of H 2 is cubed in the reaction quotient, the plant could produce the same amount of NH3 if the reactants were in a 1/6 ratio of N2/H2 and could do so at a lower pressure, which would cut operating costs. Calculate the partial pressure of each reactant and Ptotal under these conditions, assuming an unchanged partial pressure of 50 atm for NH3. Is the suggestion valid?
Phosphorus pentachloride decomposes according to the chemical equation. PCl5(g) ⇌ PCI3(g) + Cl2(g)             Kc = 1.80 at 250 °C A 0.250 mol sample of PCl5(g) is injected into an empty 2.50 L reaction vessel held at 250 °C. Calculate the concentrations of PCl5(g) and PCl3(g) at equilibrium.
Consider the following reaction and associated equilibrium constant: aA(g) ⇌ bB(g); Kcexttip{K_{ m c}}{K} = 2.6Find the equilibrium concentrations of A and B for a = 1 and b = 1. Assume that the initial concentration of A is 1.0 M and that no B is present at the beginning of the reaction.
Consider the following reaction and associated equilibrium constant: aA(g) ⇌ bB(g); Kc = 2.6Find the equilibrium concentrations of A and B for a = 2 and b = 2. Assume that the initial concentration of A is 1.0 M and that no B is present at the beginning of the reaction.
Consider the following reaction and associated equilibrium constant: aA(g) + bB(g) ⇌ cC(g); Kc exttip{K_{ m c}}{K}= 4.0Find the equilibrium concentrations of A, B, and C for a = 1, b = 1, and c = 2. Assume that the initial concentrations of A and B are each 1.0 M and that no product is present at the beginning of the reaction.
Consider the reaction CO(g) + H2O(g) ⇌ CO2(g) + H2(g); Kc = 102 at 500 KA reaction mixture initially contains 0.140 M CO and 0.140 M H2O. What will be the equilibrium concentration of CO?
Consider the reaction CO(g) + H2O(g) ⇌ CO2(g) + H2(g); Kc = 102 at 500 KA reaction mixture initially contains 0.140 M CO and 0.140 M H2O. What will be the equilibrium concentration of H2O?
Consider the reaction CO(g) + H2O(g) ⇌ CO2(g) + H2(g); Kc = 102 at 500 KA reaction mixture initially contains 0.140 M CO and 0.140 M H2O. What will be the equilibrium concentration of CO2?
Consider the reaction CO(g) + H2O(g) ⇌ CO2(g) + H2(g); Kc = 102 at 500 KA reaction mixture initially contains 0.140 M CO and 0.140 M H2O. What will be the equilibrium concentration of H2?
Consider the following reaction: HC2H3O2(aq) + H2O(l) ⇌ H3O+(aq) + C2H3O2–(aq), Kc = 1.8 x 10–5 at 25˚C. If a solution initially contains 0.220 M HC2H3O2, what is the equilibrium concentration of H3O+ at 25˚C?
Consider the following reaction: SO2Cl2(g) ⇌ SO2(g) + Cl2(g); Kc = 2.99 x 10–7 at 227 oCIf a reaction mixture initially contains 0.177 M SO2Cl2, what is the equilibrium concentration of Cl2 at 227 oC?
Consider the following reaction: Br2(g) + Cl2(g) ⇌ 2 BrCl(g); Kp = 1.11 x 10–4 at 150 K.A reaction mixture initially contains a Br2 partial pressure of 770 torr and a Cl2 partial pressure of 735 torr at 150 K. Calculate the equilibrium partial pressure of BrCl.
Consider the following reaction: CO(g) + H2O(g) ⇌ CO2(g) + H2(g); Kp = 0.0611 at 2000 KA reaction mixture initially contains a CO partial pressure of 1360 torr and a H2O partial pressure of 1760 torr at 2000 K. Calculate the equilibrium partial pressure of CO2.
Consider the following reaction: CO(g) + H2O(g) ⇌ CO2(g) + H2(g); Kp = 0.0611 at 2000 KA reaction mixture initially contains a CO partial pressure of 1360 torr and a H2O partial pressure of 1760 torr at 2000 K. Calculate the equilibrium partial pressure of H2.
Consider the following reaction: A(g) ⇌ B(g) + C(g)Find the equilibrium concentrations of A, B, and C for each of the following different values of Kc. Assume that the initial concentration of A in each case is 1.0 M and that the reaction mixture initially contains no products. Make any appropriate simplifying assumptions.Kc = 1.6
Consider the following reaction: A(g) ⇌ B(g) + C(g)Find the equilibrium concentrations of A, B, and C for each of the following different values of Kc. Assume that the initial concentration of A in each case is 1.0 M and that the reaction mixture initially contains no products. Make any appropriate simplifying assumptions. Kc = 1.6×10−5
Consider the following reaction: A(g) ⇌ 2(g)Find the equilibrium partial pressures of A and B for each of the following different values of Kp. Assume that the initial partial pressure of B in each case is 1.0 atm and that the initial partial pressure of A is 0.0 atm. Make any appropriate simplifying assumptions.Kp = 1.6 × 10−4
Nitrogen oxide is a pollutant in the lower atmosphere that irritates the eyes and lungs and leads to the formation of acid rain. Nitrogen oxide forms naturally in atmosphere according to the endothermic reaction: N2(g) + O2(g) ⇌ 2NO(g); Kp = 4.1 x 10–31 at 298 KFind the "natural" equilibrium concentration of NO in air in units of molecules/cm3.
Consider the following reaction: 2H2S(g) + SO2(g) ⇌ 3S(s) + 2H2O(g)A reaction mixture initially containing 0.510 M H2S and 0.510 M SO2 was found to contain 1.2 × 10−3 M H2O at a certain temperature. A second reaction mixture at the same temperature initially contains [H2S] = 0.255 M and [SO2] = 0.330 M. Calculate the equilibrium concentration of H2O in the second mixture at this temperature.
Hydrogen sulfide decomposes according to the following reaction, for which K c = 9.30×10−8 at 700°C: 2H2S(g) ⥫⥬ 2H2(g) + S2(g)If 0.45 mol of H2S is placed in a 3.0-L container, what is the equilibrium concentration of H 2(g) at 700°C?
Ammonia can be synthesized according to the following reaction: N 2(g) + 3H2(g) ⇌ 2NH3(g); Kp = 5.3 x 10–5 at 725 KA 200.0-L reaction container initially contains 1.27 kg of N2 and 0.310 kg of H2 at 725 K. Assuming ideal gas behavior, calculate the mass of NH3 (in g) present in the reaction mixture at equilibrium.
Ammonia can be synthesized according to the following reaction: N2(g) + 3H2(g) ⇌ 2NH3(g); Kp = 5.3 x 10–5 at 725 KA 200.0-L reaction container initially contains 1.27 kg of N2 and 0.310 kg of H2 at 725 K. What is the percent yield of the reaction under these conditions?
Even at high T, the formation of NO is not favored: N2(g) + O2(g) ⥫⥬ 2NO(g)         K c = 4.10×10−4 at 2000°C What is [NO] when a mixture of 0.20 mol of N 2(g) and 0.15 mol of O2(g) reach equilibrium in a 1.0-L container at 2000°C?
The equilibrium constant for the reaction SO2(g) + NO2(g) ⇌ SO3(g) + NO(g) is 3.1. Find the amount of NO2 that must be added to 2.5 mol of SO2 in order to form 1.3 mol of SO3 at equilibrium.
Nitrogen dioxide decomposes according to the reaction2NO2(g) ⥫⥬ 2NO(g) + O2(g)where Kp = 4.48×10−13 at a certain temperature. If 0.75 atm of NO 2 is added to a container and allowed to come to equilibrium, what are the equilibrium partial pressures of NO(g) and O2(g)?
Solid carbon can react with gaseous water to form carbon monoxide gas and hydrogen gas. The equilibrium constant for the reaction at 700.0 K is Kp = 1.6×10−3. If a 1.55-L reaction vessel initially contains 155 torr of water at 700.0 K in contact with excess solid carbon, find the percent by mass of hydrogen gas of the gaseous reaction mixture at equilibrium.
Consider the following reaction: 2NO(g) + O2(g) ⇌ 2NO2(g)A reaction mixture at 175 K initially contains 522 torr of NO and 421 torr of O2. At equilibrium, the total pressure in the reaction mixture is 748 torr. Calculate Kp at this temperature.A second reaction mixture at 175 K initially contains 255 torr of NO and 185 torr of O2. What is the equilibrium partial pressure of NO2 in this mixture?
The gas arsine, AsH3, decomposes as follows:2AsH3(g) ⇌ 2As(s) + 3H2(g)In an experiment at a certain temperature, pure AsH 3(g) was placed in an empty, rigid, sealed flask at a pressure of 392.0 torr. After 48 hours the pressure in the flask was observed to be constant at 488.0 torr.b. Calculate Kp for this reaction.
The reaction X2(g) ⇌ 2X(g) occurs in a closed reaction vessel at constant volume and temperature. Initially, the vessel contains only X2 at a pressure of 1.75 atm. After the reaction reaches equilibrium, the total pressure is 2.75 atm.What is the value of the equilibrium constant, Kp, for the reaction?
At 25ºC, gaseous SO2Cl2 decomposes to SO2(g) and Cl2(g) to the extent that 12.5% of the original SO2Cl2 (by moles) has decomposed to reach equilibrium. The total pressure (at equilibrium) is 0.900 atm. Calculate the value of Kp for this system.
A toxicologist studying mustard gas, S(CH2CH2Cl)2, a blistering agent, prepares a mixture of 0.675 M SCl2 and 0.973 M C2H4 and allows it to react at room temperature (20.0°C):SCl2(g) + 2C2H4(g) ⥫⥬ S(CH2CH2Cl)2(g)At equilibrium, [S(CH2CH2Cl)2] = 0.350 M. Calculate Kp.
The first step in HNO3 production is the catalyzed oxidation of NH3. Without a catalyst, a different reaction predominates:         4NH 3(g) + 3O2(g) ⥫⥬ 2N2(g) + 6H2O(g)When 0.0150 mol of NH3(g) and 0.0150 mol of O2(g) are placed in a 1.00-L container at a certain temperature, the N2 concentration at equilibrium is 1.96×10−3 M. Calculate Kc.
Consider the following reaction: SO2Cl2(g) ⇌ SO2(g) + Cl2(g)A reaction mixture is made containing an initial [SO2Cl2] left[ {{ m{SO}}_2 { m{Cl}}_2 } ight] of 2.3×10−2 M. At equilibrium, [Cl2] = 1.2×10−2 M. Calculate the value of the equilibrium constant (Kc).
Consider the following reaction: 2CH4(g) ⇌ C2H2(g) + 3H2(g)The reaction of CH4 is carried out at some temperature with an initial concentration of [CH4] = 0.089 M. At equilibrium, the concentration of H2 is 0.016 M. Find the equilibrium constant at this temperature.
Consider the formation of ammonia in two experiments. (a) To a 1.00-L container at 727°C, 1.30 mol of N 2 and 1.65 mol of H2 are added. At equilibrium, 0.100 mol of NH3 is present. Calculate the equilibrium concentrations of N 2 and H2, and find Kc for the reaction: 2NH3(g) ⇌ N2(g) + 3H2(g) (b) In a different 1.00-L container at the same temperature, equilibrium is established with 8.34 x 10−2 mol of NH3, 1.50 mol of N2, and 1.25 mol of H2 present. Calculate Kc for the reaction: NH3(g) ⇌ 1/2N2(g) + 3/2H2(g) What is the relationship between the Kc values in parts (a) and (b)? Why aren’t these values the same?
In a study of synthetic fuels, 0.100 mol of CO and 0.100 mol of water vapor are added to a 20.00-L container at 900.°C, and they react to form CO2 and H2. At equilibrium, [CO] is 2.24×10−3 M. (a) Calculate Kc at this temperature.
An engineer examining the oxidation of SO 2 in the manufacture of sulfuric acid determines that Kc = 1.7 x 108 at 600 K: 2SO2(g) + O2(g) ⇌ 2SO3(g) (b) The engineer places a mixture of 0.0040 mol of SO 2(g) and 0.0028 mol of O2(g) in a 1.0-L container and raises the temperature to 1000 K. At equilibrium, 0.0020 mol of SO3(g) is present. Calculate Kc and PSO2 for this reaction at 1000 K.
A 1.00-L flask was filled with 2.00 moles of gaseous SO 2 and 2.00 moles of gaseous NO2 and heated. After equilibrium was reached, it was found that 1.30 moles of gaseous NO was present. Assume that the reactionSO2(g) + NO2(g) ⇌ SO3(g) + NO(g)occurs under these conditions. Calculate the value of the equilibrium constant, K, for this reaction.
A sample of S8(g) is placed in an otherwise empty rigid container at 1325 K at an initial pressure of 1.00 atm, where it decomposes to S2(g) by the reactionS8(g) ⇌ 4S2(g)At equilibrium, the partial pressure of S8 is 0.25 atm. Calculate Kp for this reaction at 1325 K.
At a particular temperature, 12.0 moles of SO3 is placed into a 3.0-L rigid container, and the SO3 dissociates by the reaction2SO3(g) ⇌ 2SO2(g) + O2(g)At equilibrium, 3.0 moles of SO2 is present. Calculate K for this reaction.
At a particular temperature, 8.0 moles of NO2 is placed into a 1.0-L container and the NO2 dissociates by the reaction2NO2(g) ⇌ 2NO(g) + O2(g)At equilibrium the concentration of NO(g) is 2.0 M. Calculate K for this reaction.
A mixture of 1.374 g of H2 and 70.31 g of Br2 is heated in a 2.00 L vessel at 700 K . These substances react as follows:H2(g) + Br2(g) 2HBr(g)At equilibrium the vessel is found to contain 0.566 g of H2.Calculate Kc.
A sample of solid ammonium chloride was placed in an evacuated container and then heated so that it decomposed to ammonia gas and hydrogen chloride gas. After heating, the total pressure in the container was found to be 4.4 atm. Calculate Kp at this temperature for the decomposition reactionNH4Cl(s) ⇌ NH3(g) + HCl(g)
A 0.010 M solution of the weak acid HA has an osmotic pressure (see chapter on solutions and colloids) of 0.293 atm at 25°C. A 0.010 M solution of the weak acid HB has an osmotic pressure of 0.345 atm under the same conditions.(a) Which acid has the larger equilibrium constant for ionization HA [HA(aq) ⇌ A−(aq) + H+(aq)] or HB [HB(aq) ⇌ H+(aq) + B−(aq)] ?
A 0.010 M solution of the weak acid HA has an osmotic pressure (see chapter on solutions and colloids) of 0.293 atm at 25°C. A 0.010 M solution of the weak acid HB has an osmotic pressure of 0.345 atm under the same conditions.HA [HA(aq) ⇌ A−(aq) + H+(aq)] or HB [HB(aq) ⇌ H+(aq) + B−(aq)] ?What are the equilibrium constants for the ionization of these acids?
The density of trifluoroacetic acid vapor was determined at 118.1 °C and 468.5 torr, and found to be 2.784 g/L. Calculate Kc for the association of the acid.
Consider the decomposition of the compound C5H6O3 as follows:C5H6O3(g) → C2H6(g) + 3CO(g)When a 5.63-g sample of pure C5H6O3(g) was sealed into an otherwise empty 2.50-L flask and heated to 200.ºC, the pressure in the flask gradually rose to 1.63 atm and remained at that value. Calculate K for this reaction.
For the reaction A(g) ⇌ 2 B(g), a reaction vessel initially contains only A at a pressure of PA = 1.26 atm. At equilibrium, PA = 0.28 atm. Calculate the value of Kp. (Assume no changes in volume or temperature.)
For the reaction 2 A(g) ⇌ B(g) + 2 C(g), a reaction vessel initially contains only A at a pressure of PA = 260mmHg. At equilibrium, PA = 61mmHg. Calculate the value of Kp. (Assume no changes in volume or temperature.)
Consider the following reaction: Fe3+(aq) + SCN–(aq) ⇌ FeSCN2+(aq). A solution is made containing an initial [Fe3+]left[ {{ m{Fe}}^{3 + } } ight] of 1.2×10−3 M and an initial [SCN–]left[ {{ m{SCN}}^ - } ight] of 8.1×10−4 M. At equilibrium, [FeSCN2+] = 1.8×10−4 M. Calculate the value of the equilibrium constant (Kc).
Consider the following reaction: H2(g) + I2(g) ⇌ 2 HI(g)A reaction mixture in a 3.68 L flask at a certain temperature initially contains 0.764 g H2 and 96.9 g I2. At equilibrium, the flask contains 90.4 g HI. Calculate the equilibrium constant (Kc) for the reaction at this temperature.
Consider the following reaction: CO(g) + 2 H2(g) ⇌ CH3OH(g)A reaction mixture in a 5.20-L flask at a certain temperature initially contains 27.0 g CO and 2.35 g H2. At equilibrium, the flask contains 8.65 g CH3OH. Calculate the equilibrium constant (Kc ) for the reaction at this temperature.
A mixture of 3.00 volumes of H2 and 1.00 volume of N2 reacts at 344°C to form ammonia. The equilibrium mixture at 110. atm contains 41.49% NH3 by volume. Calculate Kp for the reaction, assuming that the gases behave ideally.
A 0.72-mol sample of PCl 5 is put into a 1.00-L vessel and heated. At equilibrium, the vessel contains 0.40 mol of PCl3(g) and 0.40 mol of Cl2(g). Calculate the value of the equilibrium constant for the decomposition of PCl5 to PCl3 and Cl2 at this temperature.
At 1 atm and 25 °C, NO2 with an initial concentration of 1.00 M is 3.3 × 10−3% decomposed into NO and O2. Calculate the value of the equilibrium constant for the reaction.2NO2(g) ⇌ 2NO(g) + O2(g)
A reaction vessel at 27 oC contains a mixture of SO2 (P = 3.10 atm) and O2 (P = 1.20 atm). When a catalyst is added, the reaction 2SO2(g) + O2(g) ⇌ 2SO3(g) takes place. At equilibrium the total pressure is 4.05 atm. Find the value of Kc.
At a certain temperature, K = 1.1 x 10 3 for the reactionFe3+(aq) + SCN -(aq) ⇌ FeSCN 2+(aq)Calculate the concentrations of Fe3+, SCN -, and FeSCN2+ at equilibrium if 0.020 mole of Fe(NO3)3 is added to 1.0 L of 0.10 M KSCN. (Neglect any volume change.)
For the reactionPCl5(g) ⇌ PCl3(g) + Cl2(g)at 600. K, the equilibrium constant, Kp, is 11.5. Suppose that 2.450 g PCl 5 is placed in an evacuated 500.-mL bulb, which is then heated to 600. K.b. What is the partial pressure of PCl 5 at equilibrium?
For the reactionPCl5(g) ⇌ PCl3(g) + Cl2(g)at 600. K, the equilibrium constant, Kp, is 11.5. Suppose that 2.450 g PCl 5 is placed in an evacuated 500.-mL bulb, which is then heated to 600. K.a. What would be the pressure of PCl5 if it did not dissociate?b. What is the partial pressure of PCl5 at equilibrium?c. What is the total pressure in the bulb at equilibrium?
Calculate the pressures of NO, Cl 2, and NOCl in an equilibrium mixture produced by the reaction of a starting mixture with 4.0 atm NO and 2.0 atm Cl2. (Hint: KP is small; assume the reverse reaction goes to completion then comes back to equilibrium.)2NO(g) + Cl2(g) ⇌ 2NOCl(g)             K P = 2.5 × 103
For the reactionPCl5(g) ⇌ PCl3(g) + Cl2(g)at 600. K, the equilibrium constant, Kp, is 11.5. Suppose that 2.450 g PCl 5 is placed in an evacuated 500.-mL bulb, which is then heated to 600. K.a. What would be the pressure of PCl5 if it did not dissociate?b. What is the partial pressure of PCl5 at equilibrium?c. What is the total pressure in the bulb at equilibrium?d. What is the percent dissociation of PCl 5 at equilibrium?
For the reaction shown here, Kc = 0.513 at 500 K: N2O4(g) ⇌ 2N2O(g)If a reaction vessel initially contains an N2O4 concentration of 5.50×10−2 M at 500 K, what are the equilibrium concentrations of N2O4 and NO2 at 500 K?
A student solved the following problem and found [N 2O4] = 0.16 M at equilibrium. How could this student recognize that the answer was wrong without reworking the problem? The problem was: What is the equilibrium concentration of N2O4 in a mixture formed from a sample of NO2 with a concentration of 0.10 M?2NO2(g) ⇌ N2O4(g)           K c = 160
At 700 K, CCl4 decomposes to carbon and chlorine. The Kp for the decomposition is 0.76. Find the starting pressure of CCl4 at this temperature that produces a total pressure of 1.6 atm at equilibrium.        
For the following reaction, Kc = 255 at 1000 K: CO(g) + Cl2(g) ⇌ COCl2(g)If a reaction mixture initially contains a CO concentration of 0.1510 and a Cl2 concentration of 0.175 at 1000K. What is the equilibrium concentration of CO at 1000 K?
For the following reaction, Kc = 255 at 1000 K: CO(g) + Cl2(g) ⇌ COCl2(g)If a reaction mixture initially contains a CO concentration of 0.1510 and a Cl2 concentration of 0.175 at 1000K. What is the equilibrium concentration of Cl2 at 1000 K?
For the following reaction, Kc = 255 at 1000 K: CO(g) + Cl2(g) ⇌ COCl2(g)If a reaction mixture initially contains a CO concentration of 0.1510 and a Cl2 concentration of 0.175 at 1000K. What is the equilibrium concentration of COCl2 at 1000 K?
Consider the following reaction: N2O4(g) ⇌ 2NO2(g), Kc = 0.36 at 2000 oC.The reaction mixture initially contains only the reactant, [N2O4] = 0.0260 M , and no NO2. Find the equilibrium concentration of N2O4.
Consider the following reaction: N2O4(g) ⇌ 2NO2(g), Kc = 0.36 at 2000 oC.The reaction mixture initially contains only the reactant, [N2O4] = 0.0260 M , and no NO2. Find the equilibrium concentration of NO2.
Solve each of the expressions for x using the quadratic formula and the x is small approximation. In which of the following expressions is the x is small approximation valid?x2/(0.2 - x) = 1.3 x 104
Solve each of the expressions for x using the quadratic formula and the x is small approximation. In which of the following expressions is the x is small approximation valid?x2/(0.2 - x) = 1.3 x 10–4
Solve each of the expressions for x using the quadratic formula and the x is small approximation. In which of the following expressions is the x is small approximation valid?x2/(0.01 - x) = 1.3 x 10–4
Phosgene (COCl2) is a toxic substance that forms readily from carbon monoxide and chlorine at elevated temperatures: CO(g) + Cl2(g) ⇌ COCl2(g) If 0.350 mol of each reactant is placed in a 0.500-L flask at 600 K, what are the concentrations of all three substances at equilibrium (Kc = 4.95 at this temperature)?
What are all concentrations after a mixture that contains [H 2O] = 1.00 M and [Cl 2O] = 1.00 M comes to equilibrium at 25°C?H2O(g) + Cl2O(g) ⇌ 2HOCl(g)             K  c = 0.0900
At 2200ºC, Kp = 0.050 for the reactionN2(g) + O2(g) ⇌ 2NO(g)What is the partial pressure of NO in equilibrium with N 2 and O2 that were placed in a flask at initial pressures of 0.80 and 0.20 atm, respectively?
At 25ºC, K = 0.090 for the reactionH2O(g) + Cl2O(g) ⇌ 2HOCl(g)Calculate the concentrations of all species at equilibrium for each of the following cases.a. 1.0 g H2O and 2.0 g Cl2O are mixed in a 1.0-L flask.
At 25ºC, K = 0.090 for the reactionH2O(g) + Cl2O(g) ⇌ 2HOCl(g)Calculate the concentrations of all species at equilibrium for each of the following cases.b. 1.0 mole of pure HOCl is placed in a 2.0-L flask.
At 1100 K, Kp = 0.25 for the reaction2SO2(g) + O2(g) ⇌ 2SO3(g)Calculate the equilibrium partial pressures of SO2, O2, and SO3 produced from an initial mixture in which PSO2 = PO2 = 0.50 atm and PSO3 = 0. (Hint: If you don’t have a graphing calculator, then use the method of successive approximations to solve, as discussed in Appendix 1.4.)
At a particular temperature, Kp = 0.25 for the reaction N2O4(g) ⇌ 2NO2(g)a. A flask containing only N2O4 at an initial pressure of 4.5 atm is allowed to reach equilibrium. Calculate the equilibrium partial pressures of the gases.
Consider the reaction between H2 and O2 at 1000 K2H2(g) + O2(g) ⇌ 2H2O(g)   If 0.500 atm of H2 and 0.500 atm of O2 are allowed to come to equilibrium at this temperature, what are the partial pressures of the components?
The following reaction can be used to make H 2 for the synthesis of ammonia from the greenhouse gases carbon dioxide and methane:CH4(g) + CO2(g) ⥫⥬ 2CO(g) + 2H2(g)(a) What is the percent yield of H2 when an equimolar mixture of CH 4 and CO2 with a total pressure of 20.0 atm reaches equilibrium at 1200. K, at which Kp = 3.548×106?
The hydrolysis of the sugar sucrose to the sugars glucose and fructose follows a first-order rate equation for the disappearance of sucrose.C12 H22 O11(aq) + H2 O(l) ⟶ C6 H12 O6(aq) + C6 H12 O6(aq)Rate = k[C12H22O11]In neutral solution, k = 2.1 × 10 −11/s at 27 °C. (As indicated by the rate constant, this is a very slow reaction. In the human body, the rate of this reaction is sped up by a type of catalyst called an enzyme.) (Note: That is not a mistake in the equation—the products of the reaction, glucose and fructose, have the same molecular formulas, C6H12O6, but differ in the arrangement of the atoms in their molecules). The equilibrium constant for the reaction is 1.36 × 105 at 27 °C. What are the concentrations of glucose, fructose, and sucrose after a 0.150 M aqueous solution of sucrose has reached equilibrium? Remember that the activity of a solvent (the effective concentration) is 1.
Liquid N2O3 is dark blue at low temperatures, but the color fades and becomes greenish at higher temperatures as the compound decomposes to NO and NO2. At 25 °C, a value of KP = 1.91 has been established for this decomposition. If 0.236 moles of N 2O3 are placed in a 1.52-L vessel at 25 °C, calculate the equilibrium partial pressures of N2O3(g), NO2(g), and NO(g).
Consider the following reaction and associated equilibrium constant: aA(g) ⇌ bB(g); Kc = 2.6Find the equilibrium concentrations of A and B for a exttip{a}{a}= 1 and b exttip{b}{b}= 2. Assume that the initial concentration of A is 1.0 M and that no B is present at the beginning of the reaction.
Consider the following reaction and associated equilibrium constant: aA(g) + bB(g) ⇌ cC(g); Kc = 4.0Find the equilibrium concentrations of A, B, and C for a = 1, b = 1, and c = 1. Assume that the initial concentrations of A and B are each 1.0 M and that no product is present at the beginning of the reaction.
Consider the reaction: NiO(s) + CO(g) ⇌ Ni(s) + CO2(g); Kc =4000.0 at 1500 KWhen calculating the answer, do not round to the appropriate number of significant figures until the last calculation step. If a mixture of solid nickel(II) oxide and 0.16000 M carbon monoxide is allowed to come to equilibrium at 1500 K, what will be the equilibrium concentration of CO2?
Consider the following reaction: A(g) ⇌ B(g) + C(g)Find the equilibrium concentrations of A, B, and C for each of the following different values of Kc. Assume that the initial concentration of A in each case is 1.0 M and that the reaction mixture initially contains no products. Make any appropriate simplifying assumptions. Kc = 1.6×10−2
Consider the following reaction: A(g) ⇌ 2(g)Find the equilibrium partial pressures of A and B for each of the following different values of Kp. Assume that the initial partial pressure of B in each case is 1.0 atm and that the initial partial pressure of A is 0.0 atm. Make any appropriate simplifying assumptions. Kp = 1.6
Consider the following reaction: A(g) ⇌ 2(g)Find the equilibrium partial pressures of A and B for each of the following different values of Kp. Assume that the initial partial pressure of B in each case is 1.0 atm and that the initial partial pressure of A is 0.0 atm. Make any appropriate simplifying assumptions. Kp = 1.6×105
The reaction CO2(g) + C(s) ⇌ 2CO(g) has Kp = 5.78 at 1200 K. Calculate the total pressure at equilibrium when 4.71 g of CO2 is introduced into a 10.0-L container and heated to 1200 K in the presence of 3.01 g of graphite.
The reaction CO2(g) + C(s) ⇌ 2CO(g) has Kp = 5.78 at 1200 K. Calculate the total pressure at equilibrium when 4.45 g of CO2 is introduced into a 10.0-L container and heated to 1200 K in the presence of 0.38 g of graphite.
Ammonium hydrogen sulfide decomposes according to the following reaction, for which Kp = 0.11 at 250°C:  NH4HS(s) ⥫⥬ H2S(g) + NH3(g)If 55.0 g of NH4HS(s) is placed in a sealed 5.0-L container, what is the partial pressure of NH 3(g) at equilibrium?
Hydrogen can be extracted from natural gas according to the following reaction: CH4(g) + CO2(g) ⇌ 2 CO(g) + 2H2(g);  Kp = 4.5 x 102 at 825 KAn 85.0-L reaction container initially contains 22.3 kg of CH4 and 55.4 kg of CO2 at 825 K. Assuming ideal gas behavior, calculate the mass of H2 (in g) present in the reaction mixture at equilibrium.
Hydrogen can be extracted from natural gas according to the following reaction: CH4(g) + CO2(g) ⇌ 2 CO(g) + 2H2(g); Kp = 4.5 x 102 at 825 KAn 85.0-L reaction container initially contains 22.3 kg of CH4 and 55.4 kg of CO2 at 825 K. What is the percent yield of the reaction under these conditions?
Calculate the equilibrium concentrations of NO, O 2, and NO2 in a mixture at 250 °C that results from the reaction of 0.20 M NO and 0.10 M O2. (Hint: K is large; assume the reaction goes to completion then comes back to equilibrium.)2NO(g) + O2(g) ⇌ 2NO2(g)             K c = 2.3 × 10 5 at 250 °C
Calculate the equilibrium concentrations that result when 0.25 M O 2 and 1.0 M HCl react and come to equilibrium.4HCl(g) + O2(g) ⇌ 2Cl2(g) + 2H2 O(g)             K c = 3.1 × 1013
Carbon monoxide and chlorine gas react to form phosgene: CO(g) + Cl2(g) ⇌ COCl2(g); Kp = 3.10 at 700 KIf a reaction mixture initially contains 326 torr of CO and 326 torr of Cl2, what is the mole fraction of COCl2 when equilibrium is reached?
One of the important reactions in the formation of smog is represented by the equationO3(g) + NO(g) ⇌ NO2(g) + O2(g)                   K P = 6.0 × 1034What is the pressure of O3 remaining after a mixture of O3 with a pressure of 1.2 × 10 −8 atm and NO with a pressure of 1.2 × 10−8 atm comes to equilibrium? (Hint: KP is large; assume the reaction goes to completion then comes back to equilibrium.)
Consider the following reaction: 2SO2(g) + O2(g) ⇌ 2SO3(g); Kp = 0.355 at 950 KA 2.75-L reaction vessel at 950 K initially contains 0.100 mol of SO2 and 0.100 mol of O2. Calculate the total pressure (in atmospheres) in the reaction vessel when equilibrium is reached.
Nitric oxide reacts with chlorine gas according to the following reaction: 2NO(g) + Cl2(g) ⇌ 2NOCl(g); Kp = 0.27 at 700 KA reaction mixture initially contains equal partial pressures of  NO and Cl2. At equilibrium, the partial pressure of NOCl was measured to be 115 torr. What were the initial partial pressures of NO and Cl2?
At a given temperature a system containing O2(g) and some oxides of nitrogen can be described by the following reactions:2NO(g) + O2(g) ⇌ 2NO2(g); Kp = 1042NO2(g) ⇌ N2O4(g); Kp = 0.10A pressure of 1 atm of N2O4(g) is placed in a container at this temperature. Predict which, if any component (other than N2O4) will be present at a pressure greater than 0.2 atm at equilibrium.
When N2O5(g) is heated it dissociates into N2O3(g) and O2(g) according to the following reaction:N2O5(g) ⇌ N2O3(g) + O2(g); Kc = 7.75 at a given temperatureThe N2O3(g) dissociates to give N2O(g) and O2(g) according the following reaction:N2O3(g) ⇌ N2O(g) + O2(g); Kc = 4.00 at the same temperatureWhen 4.00 mol of N2O5(g) is heated in a 1.00-L reaction vessel to this temperature, the concentration of O2(g) at equilibrium is 4.50 mol/L. Find the concentration of N2O5 in the equilibrium system.
When N2O5(g) is heated it dissociates into N2O3(g) and O2(g) according to the following reaction:N2O5(g) ⇌ N2O3(g) + O2(g); Kc = 7.75 at a given temperatureThe N2O3(g) dissociates to give N2O(g) and O2(g) according the following reaction:N2O3(g) ⇌ N2O(g) + O2(g); Kc = 4.00 at the same temperatureWhen 4.00 mol of N2O5(g) is heated in a 1.00-L reaction vessel to this temperature, the concentration of O2(g) at equilibrium is 4.50 mol/L. Find the concentration of N2O in the equilibrium system.
When N2O5(g) is heated it dissociates into N2O3(g) and O2(g) according to the following reaction:N2O5(g) ⇌ N2O3(g) + O2(g); Kc = 7.75 at a given temperatureThe N2O3(g) dissociates to give N2O(g) and O2(g) according the following reaction:N2O3(g) ⇌ N2O(g) + O2(g); Kc = 4.00 at the same temperatureWhen 4.00 mol of N2O5(g) is heated in a 1.00-L reaction vessel to this temperature, the concentration of O2(g) at equilibrium is 4.50 mol/L. Find the concentration of N2O3 in the equilibrium system.
A reaction A(g) ⇌ B(g) has an equilibrium constant of 1.0 x 10–4. For which of the initial reaction mixtures is the x is small approximation most likely to apply?a. [A] = 0.0010 M; [B] = 0.00 Mb. [A] = 0.00 M; [B] = 0.10 Mc. [A] = 0.10 M; [B] = 0.10 Md. [A] = 0.10 M; [B] = 0.00 M
Complete the changes in concentrations for each of the following reactions:(a) AgI(s) ⟶ Ag+(aq)    +    I−(aq)                         x                   ___  
For the generic reaction, A(g) ⇌ B(g), consider each value of K and initial concentration of A. For which set will the x is small approximation most likely apply?(a) K = 1.0 x 10–5; [A] = 0.250 M(b) K = 1.0 x 10–5; [A] = 0.250 M(c) K = 1.0 x 10–5; [A] = 0.00250 M(d) K = 1.0 x 10–5; [A] = 0.00250 M
Complete the changes in concentrations for each of the following reactions:(b) CaCO3(s) ⟶ Ca2+(aq) + CO32−(aq)                             ____            x
Complete the changes in concentrations for each of the following reactions:(c) Mg(OH)2(s) ⟶ Mg2+(aq) + 2OH−(aq)                                     x            _____
Complete the changes in concentrations for each of the following reactions:(d) Mg3(PO4 )2(s) ⟶ 3Mg2+(aq) + 2PO43−(aq)                                                         x_____
Complete the changes in concentrations for each of the following reactions:(e) Ca5(PO4 )3OH(s) ⟶ 5Ca2+(aq) + 3PO43−(aq) + OH−(aq)                                          _____             _____         x
Complete the changes in concentrations for each of the following reactions:(a) BaSO4(s) ⟶ Ba2+(aq) + SO42−(aq)                                 x            _____
Complete the changes in concentrations for each of the following reactions:(b) Ag2SO4(s) ⟶ 2Ag+(aq) + SO42−(aq)                               _____           x
Complete the changes in concentrations for each of the following reactions:(c) Al(OH)3(s) ⟶ Al3+(aq) + 3OH−(aq)                                 x            _____
Complete the changes in concentrations for each of the following reactions:(d) Pb(OH)Cl(s) ⟶ Pb2+(aq) + OH−(aq) + Cl−(aq)                                 _____           x           _____
Complete the changes in concentrations for each of the following reactions:(e) Ca3(AsO4)2(s) ⟶ 3Ca2+(aq) + 2AsO43−(aq)                                        3x              _____
In a given experiment, 5.2 moles of pure NOCl was placed in an otherwise empty 2.0-L container. Equilibrium was established by the following reaction:2NOCl(g) ⇌ 2NO(g) + Cl2(g)                K = 1.6 x 10 -5a. Using numerical values for the concentrations in the Initial row and expressions containing the variable x in both the Change and Equilibrium rows, complete the following table summarizing what happens as this reaction reaches equilibrium. Let x = the concentration of Cl2 that is present at equilibrium.
Assume that the change in concentration of N 2O4 is small enough to be neglected in the following problem.N2O4(g) ⇌ 2NO2(g)      Kc = 1.07 x 10−5 in chloroformShow that the change is small enough to be neglected.
Solve each of the expressions for x using the quadratic formula and the x is small approximation. In which of the following expressions is the x is small approximation valid?a. x2/(0.2 - x) = 1.3 x 104b. x2/(0.2 - x) = 1.3c. x2/(0.2 - x) = 1.3 x 10–4d. x2/(0.01 - x) = 1.3 x 10–4
In a 3.0-L vessel, the following equilibrium partial pressures are measured: N 2, 190 torr; H2, 317 torr; NH3, 1.00 × 103 torr. N2(g) + 3H2(g) ⇌ 2NH3(g)(b) Hydrogen is removed from the vessel until the partial pressure of nitrogen, at equilibrium, is 250 torr. Calculate the partial pressures of the other substances under the new conditions.
Assume that the change in concentration of COCl 2 is small enough to be neglected in the following problem.COCl2(g) ⇌ CO(g) + Cl2(g)           K c = 2.2 × 10−10Show that the change is small enough to be neglected.
Assume that the change in pressure of H 2S is small enough to be neglected in the following problem.2H2S(g) ⇌ 2H2(g) + S2(g)               K P = 2.2 x 10 −6Show that the change is small enough to be neglected.
Complete the changes in concentrations (or pressure, if requested) for the following reaction.
Complete the changes in concentrations (or pressure, if requested) for the following reaction.
In equilibrium problems involving equilibrium constants that are small relative to the initial concentrations of reactants, we can often assume that the quantity x (which represents how far the reaction proceeds toward products) is small. When this assumption is made, the quantity x can be ignored when it is subtracted from a large number, but not when it is multiplied by a large number. In other words, 2.5 - x ≈ 2.5, but 2.5x ≠ 2.5. Explain why a small x can be ignored in the first case, but not in the second.
Complete the changes in concentrations (or pressure, if requested) for the following reaction.
Complete the changes in concentrations (or pressure, if requested) for the following reaction.
Consider the equilibrium4NO2(g) + 6H2 O(g) ⇌ 4NH3(g) + 7O2(g)(d) If the change in the pressure of NO2 is 28 torr as a mixture of the four gases reaches equilibrium, how much will the pressure of O2 change?
Complete the changes in concentrations (or pressure, if requested) for the following reaction.
Complete the changes in concentrations (or pressure, if requested) for the following reaction.
Complete the changes in concentrations (or pressure, if requested) for the following reaction.
A 1.00-L vessel at 400 °C contains the following equilibrium concentrations: N 2, 1.00 M; H2, 0.50 M; and NH3, 0.25 M. How many moles of hydrogen must be removed from the vessel to increase the concentration of nitrogen to 1.1 M?
Complete the changes in concentrations (or pressure, if requested) for the following reaction.
Complete the changes in concentrations (or pressure, if requested) for the following reaction.
Complete the changes in concentrations (or pressure, if requested) for the following reaction.
Complete the changes in concentrations (or pressure, if requested) for the following reaction.
Complete the changes in concentrations (or pressure, if requested) for the following reaction.
Gaseous PCl5 decomposes according to the reaction PCl5(g) ⥫⥬ PCl3(g) + Cl2(g)In one experiment, 0.15 mol of PCl5(g) was introduced into a 2.0-L container. Construct the reaction table for this process.
Hydrogen fluoride, HF, can be made by the reactionH2(g) + F2(g) ⥫⥬ 2HF(g)In one experiment, 0.10 mol of H2(g) and 0.050 mol of F2(g) are added to a 0.50-L flask. Write a reaction table for this process.
The decomposition of HI(g) is represented by the equation2HI(g) ⇌ H2(g) + I2(g)The following experiment was devised to determine the equilibrium constant of the reaction. HI (g) is introduced into five identical 400-cm3 glass bulbs, and the five bulbs are maintained at 623 K. The amount of I2 produced over time is measured by opening each bulb and titrating the contents with 0.0150 M Na2S2O3 (aq). The reaction of I2 with the titrant isI2 + 2Na2S2O3 ⇌ Na2S4O6 + 2NaIData for the experiment are provided in this table.What is the value of Kc for the decomposition of HI at 623 K?
For the reaction, Kc = 255 at 1000 K.CO(g) + Cl2(g) → COCl2(g)If a reaction mixture initially contains a CO concentration of 0.1550 M and a Cl2 concentration of 0.171 M at 1000 K.1. What is the equilibrium concentration of CO at 1000 K?2. What is the equilibrium concentration of Cl 2 at 1000 K?3. What is the equilibrium concentration of COCl 2 at 1000 K?
A chemist at a pharmaceutical company is measuring equilibrium constants for reactions in which drug candidate molecules bind to a protein involved in cancer. The drug molecules bind the protein in a 1:1 ratio to form a drug-protein complex. The protein concentration in aqueous solution at 25 oC is 1.72×10−6 M. Drug A is introduced into the protein solution at an initial concentration of 2.00 10-6 M. Drug B is introduced into a separate, identical protein solution at an initial concentration of 2.00 10-6 M. At equilibrium, the drug A-protein solution has an A-protein complex concentration of 1.00 10-6 M, and the drug B solution has a B-protein complex concentration of 1.40 10-6 M.Calculate the Kc value for the B-protein binding reaction.
Consider the following reaction: 2NO(g) + O 2(g) ⇌ 2NO2(g)A reaction mixture at 175 K initially contains 522 torr of NO and 421 torr of O2. At equilibrium, the total pressure in the reaction mixture is 748 torr. Calculate Kp at this temperature.
A mixture initially contains A, B, and C in the following concentrations: [A] = 0.350 M, [B] = 1.40 M, and [C] = 0.700 M. The following reaction occurs and equilibrium is established: A + 2B ⇌ C At equilibrium, [A] = 0.170 M and [C] = 0.880 M. Calculate the value of the equilibrium constant, Kc. Express your answer numerically.
At a certain temperature, the equilibrium constant K c for this reaction is 53.3.H2 + I 2 → 2 HIAt this temperature, 0.800 mol of H2 and 0.800 mol of I2 were placed in 1.00L container to react. What concentration of HI is present at equilibrium?
Consider the reaction between iodine gas and chlorine gas to form iodine monochloride: I2(g) + Cl2(g) ⇌ 2ICl(g); Kp = 81.9 (at 298 K)A reaction mixture at 298 K initially contains PI2 = 0.35 atm and PCl2 = 0.35 atm. What is the partial pressure of iodine monochloride when the reaction reaches equilibrium?
An equilibrium mixture contains 0.700 mol of each of the products (carbon dioxide and hydrogen gas) and 0.200 mol of each of the reactants (carbon monoxide and water vapor) in a 1.00-L container. CO (g) + H2O (g) ⇌ CO2 (g) + H2 (g) How many moles of carbon dioxide would have to be added at constant temperature and volume to increase the amount of carbon monoxide to 0.300 mol once equilibrium has been reestablished?
The reaction CO2 (g) + C (s) ⇌ 2CO (g) has Kp = 5.78 at 1200 K. Part ACalculate the total pressure at equilibrium when 4.62 g of CO2 is introduced into a 10.0-L container and heated to 1200 K in the presence of 3.73 g of graphite. Express your answer to three significant figures and include the appropriate units. 
At 100°C, Kc = 4.72 for the reaction 2NO2(g) ⇌ N2O4(g). An empty 10.0 L flask is filled with 9.20 g of NO2 at 100°C. What is the total pressure in the flask at equilibrium?
For the reaction, 2 A(g) ⇌ B(g) + 2 C(g), a reaction vessel initially contains only A at a pressure of PA = 264 mmHg. At equilibrium, PA = 66 mmHg. Calculate the value of K_p. (Assume no changes in volume or temperature.) Express your answer using two significant figures. 
At 25°C, the reaction 2NH3(g) ⇌ N2(g) + 3H2(g) has Kc = 2.3 x 10-9. If 0.058 mol NH3 is placed in a 2.06 L container, what will the concentrations of N2 and H2 be when equilibrium is established? Make simplifying assumptions in your calculations. Assume the change in NH3 concentration is insignificant if compared to initial value. 
For the reaction, CO(g) + Cl2(g) ⇌ COCl2(g)       Kc = 255 at 1000 K. If a reaction mixture initially contains a CO concentration of 0.1550 M and a Cl2 concentration of 0.171 M at 1000 K.What is the equilibrium concentration of CO at 1000 K?What is the equilibrium concentration of Cl 2 at 1000 K?What is the equilibrium concentration of COCl2 at 1000 K?
Consider the formation of hydrogen fluoride: H2 (g) + F2 (g) <-> 2HF (g) If a 3.0 L nickel reaction container (glass cannot be used because it reacts with HF) filled with 0.0055 M H2 is connected to a 3.4 L container filled with 0.033 M F 2. The equilibrium constant. Kp, is 7.8 x 1014. Calculate the molar concentration of HF at equilibrium. 
Be sure to answer all parts. The water-gas shift reaction plays a central role in the chemical methods for obtaining cleaner fuels from coal: CO (g) + H2O (g) ⇌ CO2 (g) + H2 (g) A study was made in which equilibrium was reached with [CO] = [H2O] = [H2] = 0.100 M and [CO2] = 0.400 M. After 1.15 mol of H2 is added to the 2.00-L container and equilibrium is reestablished, what are the new concentrations of all the components? 
The value of Kc for the thermal decomposition of hydrogen sulfide, shown below, is 2.2 x 10-4 at 1400 K.2H2S(g) ⇌ 2H2(g) + S2(g)A sample of gas in which [H2S] = 5.20 M is heated to 1400 K in a sealed vessel. After chemical equilibrium has been achieved, what is the value of [H2S]? Assume no H2 or S2 was present in the original sample.
A mixture of 0.1000 mol of CO2, 0.1000 mol of H2, and 0.1000 mol of H2O is placed into a 2.000-L vessel. The following equilibrium is established: CO2(g) + H2(g) ⇌ CO(g) + H2O(g) At equilibrium, [CO2] = 0.00954 M. Calculate the equilibrium concentrations of H2, CO, H2O, and the equilibrium constant for the reaction.
What are the concentrations of PCl 5, PCl3, and Cl2 in an equilibrium mixture produced by the decomposition of a sample of pure PCl5 with [PCl5] = 2.00 M?PCl5(g) ⇌ PCl3(g) + Cl2(g)         K c = 0.0211
A Student ran the following reaction in the laboratory at 502 K:PCl3(g) + Cl2(g) ⇌ PCl5(g)When she introduced 0.199 moles of PCI3(g) and 0.235 moles of Cl2(g) into a 1.00 liter container, she found the equilibrium concentration of Cl2(g) to be 6.84 x 10-2 M. Calculate the equilibrium constant, Kc, she obtained for this reaction.
For the reactionH2(g) + CO2(g) ⇌ H2O(g) + CO(g)at 700°C, Kc = 0.534. Calculate the number of moles of H 2 that are present at equilibrium if a mixture of 0.650 mole of CO and 0.650 mole of H2O is heated to 700°C in a 30.0-L container. 
A key step in the extraction of iron from its ore isFeO(s) + CO (g) ⇌ Fe (s) + CO2 (g) Kp = 0.403 at 1, 000°CThis step occurs in the 700°C to 1, 200°C zone within a blast furnace. What are the equilibrium partial pressures of CO(g) and CO2 (g) when 1.2200 atm of CO (g) and excess FeO(s) react in a sealed container at 1, 000°C?
At a certain temperature, the equilibrium Constant, Ko, for this reaction is 53.3. H2(g) + I2(g) ⇌ 2HI(g) Kc = 53.3 At this temperature, 0.300 mol of H2 and 0.300 mol of I2 were placed in a 1.00-L container to react. What concentration of HI s present at equilibrium? 
At a certain temperature, the Kp for the decomposition of H2S is 0.727. H2S (g) ⇌ H2 (g) + S (g) Initially, only H2S is present at a pressure of 0.165 atm in a closed container. What is the total pressure in the equilibrium?
Consider the following reaction: A (g) ⇌ B (g) + C (g) Find the equilibrium concentrations of A, B, and C for each of the following different values of Kc. Assume that the initial concentration of A in each case is 1.0 M and that the reaction mixture initially contains no products. Make any appropriate simplifying assumptions. Part BKc = 2.0 x 10-2 Express your answer using two significant figures. Enter your answers numerically separated by commas. 
The value of Kc for the reaction:N2O4 (g) ⇌ 2NO2 (g)is 0.53 at 461.5 K. Part 1 If a reaction vessel at that temperature initially contains 0.0251 MNO2 and 0.0251 MN2O4, what is the concentration of NO2 at equilibrium?Part 2What is the concentration of N2O4 at equilibrium?
Before any reaction occurs, the concentration of A In the reaction below is 0.0510 M. What is the equilibrium constant if the concentration of A at equilibrium is 0.0153 M? A (aq) ⇌ 2B (aq) + C (aq) Remember to use correct significant figures in your answer (round your answer to the nearest ten thousandth). Do not include units in your response.
At 200 °C, the equilibrium constant (Kp) for the reaction below is 2.40 x 10 3. 2NO (g) <-> N2 (g) + O2 (g) A closed vessel is initially charged with 36.1 atm of NO. At equilibrium, the partial pressure of O  2 is _____ atm. 
Enter your answer in the provided box.The equilibrium constant Kc for the equation 2H2 (g) + CO (g) ⇌ CH3OH (g) is 31 at a certain temperature. If there are 5.85 x 10-2 moles of H2 and 4.47 x 10-3 moles of CH3OH at equilibrium in a 7.63-L flask, what is the concentration of CO?
Consider the following reaction:SO2Cl2(g) ⇌ SO2(g) + Cl2(g)Kc = 2.99 × 10−7 at 227∘CIf a reaction mixture initially contains 0.177 M SO2Cl2, what is the equilibrium concentration of Cl 2 at 227∘C?
Nitrosyl bromide, NOBr, is formed in the reaction of nitric oxide, NO, with bromine, Br2 2NO(g) + Br2(g)⇌ 2NOBr(g) The reaction rapidly establishes equilibrium when the reactants are mixed. At a certain temperature the initial concentration of NO was 0.400 M and that of Br2 was 0.265 M. At equilibrium the concentration of NOBr was found to be 0.250 M. What is the value of Kc at this temperature. Express your answer numerically.
The equilibrium constant, Kc, for the following reaction is 7.00 x 10^-5 at 673 K.NH4I(s) NH3(g) + HI(g)Calculate the equilibrium concentration of HI when 0.411 moles of NH4I(s) are introduced into a 1.00 L vessel at 673 K.
The equilibrium constant Kc for the reaction:C ⇌ D + E is 8.10 x10-5. The initial composition of the reaction mixture is [C} = [D] = [E] =   1.10x10^3 M. What is the equilibrium concentration of C, D, and E?
A 0.682- g sample of ICl(g) is placed in a 625 - mL reaction vessel at 682 K. When equilibrium is reached between the ICl(g) and I2 (g) and Cl2(g) formed by its dissociation, 0.0383 g I2 (g) is present. What is KC for the reaction?
The equilibrium constant Kc for the reactionH2(g) + I2(g) ⇌ 2H1(g)is 54.3 at 430 C. At the start of the reaction, there are 0.714 mole of H_2, 0.984 mole of I2, and 0.886 mole of HI in a 2.40 L reaction chamber. Calculate the concentrations of the gases at equilibrium.
At a certain temperature, 0.720 mol of SO3 is placed in a 4.50-L container. 2SO3 (g) ⇌ 2SO2 (g) + O2 (g) At equilibrium, 0.110 mol of O2 is present. Calculate Kc. 
Calculate the value of the change in concentration from initial conditions to equilibrium ("x" in your ICE chart) for the products of the faollowing reaction:SO2(g) + NO2(g) ⇌ SO3(g) + NO(g)If the value of Kc for the reaction is 2.50 and the INITIAL concentrations of the reactants and products in the reaction mixture are 0.500 M SO2, 0.500 M NO2, 0.00500 M SO3, and 0.00500 M NO.
In a particular experiment, it was found that when O2(g) and CO(g) were mixed and allowed to react according to the equation:2CO(g) + O2(g) ⇌ 2CO2(g) the O2 concentration had decreased by 0.078 mol L-1 when the reaction reached equilibrium. How had the concentrations of CO and CO2 changed?The number of significant digits is set to 2; the tolerance is +/-1 in the 2nd significant digit.
At a certain temperature, the equilibrium constant,  Kc for this reaction is 53.3.H2(g) + I2(g) ⇌ 2HI(g)At this temperature, 0.300 mol of H2 and 0.300 mol of I2 were placed in a 1.00 L container to react. What concentration of HI is present at equilibrium? 
Suppose a 500 mL flask is filled with 1.9 mol of H2 and 1.8 mol of I2. This reaction becomes possible: H2(g) + I2(g) ⇌ 2HI(g) Complete the table below, so that it lists the initial molarity of each compound, the change in molarity of each compound due to the reaction, and the equilibrium molarity of each compound after the reaction has come to equilibrium.Use x to stand for the unknown change in the molarity of H2. You can leave out the M symbol for molarity.
At a certain temperature, the equilibrium constant for the following chemical equation is 3.50. SO2(g) + NO2(g) ⇌ SO3(g) + NO(g) At this temperature, calculate the number of moles of NO2(g) that must be added to 2.52 mol of SO2(g) in order to form 1.20 mol of SO3(g) at equilibrium.
Be sure to answer all parts.The equilibrium constant Kc for the decomposition of phosgene, COCI2, is 4.63 x 10-3 at 527 °C: COCI2 (g) ⇋ CO (g) + CI2 (g) Calculate the equilibrium partial pressure of all the components, starting with pure phosgene at 0.560 atm. PCOCI2 = PCO = PCI2 =
Consider the following  unbalanced equation at some constant temperature: CO2 (g) ⇌ CO (g) + O2 (g)       K = 5.7 x 10-7 In an experiment, 4.9 mol of CO2 and 3.1 mol of CO are initially placed into a 1.0 L rigid container. Calculate the concentration of O2 when the reaction has reached equilibrium. Please use the correct number of significant figures when entering your answer and enter your answer using exponential format. For example 1.00 x 10-27 should be entered as 1.00E-27. 
At a certain temperature, the equilibrium constant, K, for this reaction is 53.3. H2 (s) + I2 (g) ⇌ 2HI (g)           K = 533 At this temperature, the reactants were placed in a container to react. If the partial pressures of H2 and I2 were each 0.700 bar initially, what is the partial pressure of HI at equilibrium?
Suppose a 500. mL flask is filled with 1.5 mol of H 2O, 0.20 mol of CO2 and 1.2 mol of H2. The following reaction becomes possible: CO (g) + H2O (g) ⇌ CO2 (g) + H2 (g) The equilibrium constant K for this reaction is 0.223 at the temperature of the flask. Calculate the equilibrium molarity of H2O.
At a certain temperature, 0.960 mol of SO3 is placed in a 4.50-L container. 2SO3(g) ⇌ 2SO2(g) + O2(g) At equilibrium, 0.110 mol of O2 is present. Calculate Kc. 
For the reaction H2 (g) + S (g) ⇌ H2S (g) the initial concentrations are 0.060 M H2, 0.080 MS, and no H2S. At equilibrium, [H] = 0.010 M. Part 1Calculate the concentrations of S and H2S at equilibrium. (Be sure to give your answers to three decimal places.) Part 2Calculate the value of K under the reaction conditions at equilibrium. (Be sure your answer has the appropriate number of significant figures.)
Suppose a 500. mL flask is filled with 2.0 mol of N2 and 1.5 mol of NH3. This reaction becomes possible: N2 (g) + 3H2 (g) ⇌ 2NH3 (g) Complete the table below, so that it lists the initial molarity of each compound, the change in molarity of each compound due to the reaction, and the equilibrium molarity of each compound after the reaction has come to equilibrium. Use x to stand for the unknown change in the molarity of N2. You can leave out the M symbol for molarity.
At a certain temperature, 0.920 mol of SO3 is placed in a 3.50-L container. 2SO3(g) ⇌ 2SO2(g) + O2(g) At equilibrium, 0.120 mol of O2 is present. Calculate Kc. 
Consider the reaction: N2(g) + O2(g) ⇌ 2 NO(g) for which Kc = 0.10 at 2,000°C. Starting with initial concentrations of 0.15 M N2 and 0.15 M O2, determine the equilibrium concentration of NO. a. 0.020 M b. 0.13 M c. 0.0071 M d. 0.014 M e. 0.041 M
For the reaction 2HI (g) <-> H2 (g) + I2 (g)      Keq = 0.016 Initially a container contains 0.60 M HI, 0.038 M H 2, and 0.15 M I 2 at equilibrium. What is the new equilibrium concentration of H2, if the H2 concentration is increased by 0.197 M?
The equilibrium constant, Kc, for the following reaction is 10.5 at 350 K. 2CH2Cl2 ⇌ CH4 (g) + CCl4 (g) Calculate the equilibrium concentrations of reactant and products when 0.357 moles of CH2Cl2 are introduced into a 1.00 L vessel at 350 K. [CH2Cl2] = __________ M [CH4] =  __________ M[CCl4] = __________  M
Enter your answer in the provided box. Hydrogen sulfide decomposes according to the following reaction, for which Kc = 9.30 x 10-8 at 700°C: 2H2S (g) ⇌ 2H2 (g) + S2 (g)If 0.49 mol of H2S is placed in a 3.0-L container, what is the equilibrium concentration of H2(g) at 700°C?
At a certain temperature, the equilibrium constant for the following chemical equation is 3.90. SO2 (g) + NO2 (g) ⇌ SO3 (g) + NO (g) At this temperature, calculate the number of moles of NO2(g) that must be added to 3.12 mol of SO2(g) in order to form 1.30 mol of SO3(g) at equilibrium.
At a certain temperature, 0.740 mol of SO3 is placed in a 3.00-L container. 2SO3(g)  ⇌ 2SO2(g) + O2(g)At equilibrium, 0.170 mol of O2 is present. Calculate Kc.
At a certain temperature, 0.740 mol of SO3 is placed in a 5.00-L container. 2SO3(g) ⇌ 2SO2(g) + O2(g) At equilibrium, 0.100 mol of O2 is present. Calculate Kc.
The equilibrium constant Kc = 1.1 x 10-2 for the following reaction at 400 K: PCl5 (g) ⇌ PCl3 (g) + Cl2 (g) (a) Given that 1.0 g of PCl5 was initially placed in a 250 ml reaction vessel, determine the molar concentrations in the mixture at equilibrium. (b) What percentage of PCl5 is decomposed at 400 K?
Consider the following reaction. A (aq) ⇌ 2B (aq)               K  c = 7.11 x 10 -6 at 500 Klf a 4.20 M sample of A is heated to 500 K, what is the concentration of B at equilibrium? 
During an experiment, 0.294 mol of H2 and 0.294 mol of I2 were placed into a 1.15 liter vessel where the reaction H2(g) + I2(g) ⇌ 2HI(g) came to equilibrium. For this reaction, Kc = 49.5 at the temperature of the experiment. What were the equilibrium concentrations of H2, I2, and HI? 
Consider the following reaction. A (aq) ⇌ 2B (aq)      K c = 4.70 x 10 -6 at 500 K If a 4.10 M sample of A is heated to 500 K, what is the concentration (M) of B at equilibrium? 
Enter your answer in the provided box. Even at high temperatures, the formation of NO is not favored: (Kc = 4.10 x 10-4 at 2,000°C) N2 (g) + O2 (g) ⇌ 2NO (g) What is [NO] when a mixture of 0.20 mol of N2(g) and 0.22 mol of O2(g) reach equilibrium in a 1.0-L container at 2,000 °C?
Carbon disulfide is prepared by heating sulfur and charcoal. The chemical equation isS2 (g) + C (s) ⇌ CS2 (g)      Kc = 9.40 at 900 K How many grams of CS2(g) can be prepared by heating 20.5 moles of S2(g) with excess carbon in a 8.40 L reaction vessel held at 900 K until equilibrium is attained?
5.00 mol of solid A placed in a seated 1.00-L container and allowed to decompose in gaseous B and C. The concentration of B increased until it reached 1.40 M, remained constant. A (s) ⇌ B (g) + C (g) Then, the container volume was doubled and equilibrium was re-established. How many moles of A remain?
Be sure to answer all parts.The equilibrium constant Kc for the reaction H2 (g) + Br2 (g) ⇋ 2HBr (g) is 2.180 x 106 at 730°C. Starting with 2.20 moles of HBr in a 21.6-L reaction vessel, calculate the concentrations of H2, Br2 and HBr at equilibrium. 
Phosphorus pentachloride decomposes according to the chemical equation PCl5 (g) ⇌ PCl3 (g) + Cl2(g)                 K c = 1.80 at 250 °C.A 0.162 mol sample of PCl5 (g) is injected into an empty 2.10 L reaction vessel held at 250 °C. Calculate the concentrations of PCl5 (g) and PCl3 (g) at equilibrium. 
Consider the following reaction. 2A(g) ⇌ B(g)    Kp = 2.42 x 10 -5 at 500 KIf a sample of A(g) at 3.50 bar is heated to 500 K, what is the pressure of B(g) at equilibrium?PB = 
Carbon disulfide is prepared by heating sulfur and charcoal. The chemical equation is S2 (g) + C (s) ⇌ CS2 (g)       Kc = 9.40 at 900 K How many grams of CS2 (g) can be prepared by heating 13.0 moles of S2 (g) with excess carbon in a 5.85L reaction vessel held at 900 K until equilibrium is attained?
At 25 °C, the equilibrium constant Kc = 65 for the reaction 2A (aq) = B (aq) + C (aq) at 298K. If 2.50 mol of A is added to enough water to prepare 1.00 L of solution, what will the equilibrium concentration of A be? a. 0.15 M b. 1.18 M c. 0.68 M d. 0.24 M
Carbon disulfide is prepared by heating sulfur and charcoal. The chemical equation is S2 (g) + C (s) ⇌ CS2 (g)        K c = 9.40 at 900 K How many grams of CS 2(g) can be prepared by heating 13.5 moles of S 2(g) with excess carbon in a 5.95 L reaction vessel held at 900 K until equilibrium is attained?
Consider the following reaction. A (aq) ⇌ 3B (aq)         Kc = 6.84 x 10-6  at 500 K If a 1.60 M sample of A is heated to 500 K, what is the concentration of B at equilibrium?
Consider the fllowing reaction. A(aq) ⇌ 2B(aq)             Kc = 3.16 x 10-6 at 500 KIf a 2.80 M sample of A is heated to 500 K, what is the concentration of B at equilibrium? 
At a certain temperature, the Kp for the decomposition of H2S is 0.818. H2S (g) ⇌ H2 (g) + S (g) Initially, only HS is present at a pressure of 0.213 atm in a closed container. What is the total pressure in the container at equilibrium?
At a certain temperature, 0.326 m of CH 4 and 0.941 mol of H2O is placed in a 2.50 L container. CH4(g) + 2H2O(g) ⇌ CO2(g) + 4H2(g) At equilibrium, 5.28 g of CO2 is present. Calculate Kc. 
A mixture of 0.440 M H 2O, 0.310 M Cl2O, and 0.653 M HCIO are enclosed in a vessel at 25°C. H2O(g) + Cl2O(g) ⇌ 2HOCl(g)            K c = 0.090 at 25°C Calculate the equilibrium concentrations of each gas at 25°C.
At a particular temperature, 8.0 mol NO2 is placed into a 1.0-L container and the NO2 dissociates by the reaction. At equilibrium the concentration of NO(g) is 2.0 M. Calculate K for this reaction. K = _______
At equilibrium, the concentrations in this system were found to be [N2] = [O2] = 0.200 M and [NO] = 0.400 M. N2 (g) + O2 (g) ⇌ 2NO(g) If more NO is added, bringing its concentration to 0.700 M, what will the final concentration of NO be after equilibrium is re-established?
At a certain temperature, the Kp for the decomposition of H2S is 0.721. H2S(g) ⇌ H2(g) + S(g)Initially, only H2S is present at a pressure of 0.139 atm in a closed container. What is the total pressure in the container at equilibrium? 
The equilibrium constant Kc = 49 for the reaction: PCl3 (g) + Cl2 (g) ⇌ PCl5 (g) at 230 °C. If 0.70 mol of PCl3 is added to 0.70 mol of Cl2 in a 1.00-L reaction vessel at 230 °C, what is the concentration of PCl3 when equilibrium has been established? a. 0.59 M b. 0.30 M c. 0.11 M d. 0.83 M
Before any reaction occurs, the concentration of A in the reaction below is 0.049 M. What is the equilibrium constant if the concentration of A at equilibrium is 0.0196 M? A(g) ⇌ B (g) + 2C (g)
At a certain temperature, 0.3811 mol of N2 and 1.641 mol of H2 are placed in a 3.00-L container. N2 (g) + 3H2 (g) ⇌ 2NH3 (g) At equilibrium, 0.1001 mol of N2 is present. Calculate the equilibrium constant, Kc.
1.0 mol each of H2, I2, and HI are placed in a 2.0L reaction vessel at 1200K. Kc for the reaction H2(g) + I2(g) ⇌ 2Hl(g) is 4.6 at the given temperature. What is the equilibrium concentration of HI?
Part BThe following reaction was performed in a sealed vessel at 751°C: H2 (g) + I2 (g) ⇌ 2HI (g) Initially, only H2 and I2 were present at concentrations of [H2] = 3.35 M and [I2] = 2.35M. The equilibrium concentration of I2 is 0.0600 M. What is the equilibrium constant. Kc, for the reaction at this temperature? Express your answer numerically.
Calculate the equilibrium concentrations of N2O4 and NO2 at 25°C in a vessel that contains an initial N2O4 concentration of 0.0376 M The equilibrium constant Kc for the reaction N2O4(g) ⇌ 2NO2(g) is 4.64 x 10-3 at 25°C.
Phosphorus pentachloride decomposes according to the chemical equation PCl5 (g) ⇌ PCl3 (g) + Cl2 (g)    Kc = 1.80 at 250°C A 0.179 mol sample of PCI5(g) is injected into an empty 2.50 L reaction vessel held at 250°C. Calculate the concentrations of PCl5(g) and PCl3(g) at equilibrium.
At a certain temperature, the Kp for the decomposition of H2S is 0.821. H2S (g) ⇌ H2 (g) + S (g) Initially, only H2S is present at a pressure of 0.270 atm in a closed container. What is the total pressure in the container at equilibrium?
When 1.00 mol of A and 0.800 mol of B are placed in a 2.00 L container and allowed to come to equilibrium, the resulting mixture is found to be 0.20M in D. What is the value of K at equilibrium? (This problem requires extra step of using quantity and volume to convert to molarity. Here I'm giving you moles: in lab you might instead be starting with grams, and needing to convert grams to moles, then moles to molarity.)
At a certain temperature, the Kp for the decomposition of H2S is 0.859. H2S (g) ⇌ H2 (g) + S (g) Initially, only H2S is present at a pressure of 0.145 atm in a closed container. What is the total pressure in the container at equilibrium?
Consider the following reaction. 2A(g) ⇌ B(g)    Kp = 4.84 x 10 -5 at 500 KIf a sample of A(g) at 1.90 atm is heated to 500 K, what is the pressure of B(g) at equilibrium?PB = 
When HNO2 is dissolved in water it partially dissociates according to the equation HNO2 ⇌ H+ + NO2-. A solution is prepared that contains 3.000 g of HNO2 in 1.000 kg of water. Its freezing point is found to be -0.1281°C Calculate the fraction of HNO2 that has dissociated. Express your answer using two significant figures. 
Calculate the equilibrium concentrations of H2, I2 and HI at 500K. The equilibrium constant Kc at 500K for the reaction H2(g) + I2(g) ⇌ 2HI(g) is 129.
At a certain temperature, the K for the decomposition of H2S is 0.812. H2S (g) ⇌ H2 (g) + S (g) Initally, only H2S is present at a pressure of 0.237 bar in a closed container. What is the total pressure in the container at equilibrium?
Be sure to answer all parts.The equilibrium constant Kc for the reaction below is 0.00209 at a certain temperature. Br2 (g) ⇌ 2Br (g) If the initial concentrations are [Br2] = 0.0335 M and [Br] = 0.0617 M, calculate the concentrations of these species at equilibrium. [Br2] = [Br] = 
At 473 K, for the elementary reaction 2NOCl (g) k1k-1⇌ 2NO (g) + Cl2 (g)k1 = -7.8 x 10-2 L/mols and k-1 = 4.7 × 102 L2/mol2sA sample of NOCl is placed in a container and heated to 473 K. When the system comes to equilibrium, [NOCI] is found to be 0.60 mol/L.Part AFind the concentration of NO.Express your answer to two significant figures and include the appropriate units. Part B Find the concentration of Cl2. Express your answer to two significant figures and include the appropriate units.
Using the Equilibrium constant The reversible chemical reaction A + B ⇌ C + D has the following equilibrium constant. Kc = [C][D]/[A][B] = 2.7 Part A Initially, only A and B are present, each at 2.00 M. What is the final concentration of A once equilibrium is reached?Express the molar concentration numerically using two significant figures.
Phosphorus pentachloride decomposes according to the chemical equation PCI5(g) ⇌ PCI3(g) + Cl2(g)         Kc = 1.80 at 250°C A 0.250 mol sample of PCI5(g) is injected into an empty 2.90 L reaction vessel held at 250°C. Calculate the concentrations of PCl5(g) and PCl3(g) at equilibrium. [PCl5] = [PCl3] =
At some temperature, 0.765 moles of NO(g) and 0.400 moles of O2(g) are introduced into a 1.00 L reaction vessel and allowed to come to equilibrium according to the following equation:2NO(g) + O2(g) → 2 NO2(g) At equilibrium, there are 0.725 moles of NO2(g) formed. What is the value of Kc? 
2.0 mol each of PCl5, PCl3, and Cl2 are placed in a 2.0L reaction vessel at 620K. Kc for the reaction PCl5(g) ⇌ PCl3(g) + Cl2(g) is 0.60 at the given temperature. What is the equilibrium concentration of Cl2?
At a certain temperature, the equilibrium constant for the following chemical equation is 3.80. SO2 (g) + NO2 (g) ⇌ SO3 (g) + NO (g) At this temperature, calculate the number of moles of NO 2 (g) that must be added to 2.76 mol of SO2 (g) in order to form 1.20 mol of SO 3 (g) at equilibrium.
At a certain temperature, 0.4611 mol of N2 and 1.541 mol of H2 are placed in a 3.00-L container.At equilibrium, 0.1201 mol of N2 is present. Calculate the equilibrium constant, Kc.
In a study of the formation of NOx air pollution, a chamber heated to 2200°C was filled with air (0.790 atm N2, 0.210 atm O2). What are the equilibrium partial pressures of N2, O2, and NO if Kp = 0.0500 for the following reaction: N2 (g)+ O2 (g) ⇌ 2NO (g) 
At a certain temperature, the Kp for the decomposition of H2S is 0.782. H2S (g) ⇌ H2 (g) + S (g) Initially, only H2S is present at a pressure of 0.183 atm in a closed container. What is the total pressure in the container at equilibrium?
At a certain temperature, O.960 mol of SO3 is placed in a 3.00-L container. 2SO3 (g) ⇌ 2SO2 (g) + O2 (g) At equilibrium, 0.130 mol of O2 is present. Calculate Kc. 
At a certain temperature, the equilibrium constant, Kc, for this reaction is 53.3. H2 (g) + I2 (g) ⇌ 2HI (g)             Kc = 53.3 At this temperature, 0.400 mol of H2 and 0.400 mol of I2 were placed in a 1.00 - L container to react. What concentration of HI is present at equilibrium?
A mixture of 0.500 mole of carbon monoxide and 0.400 mole of bromine was placed into a rigid 1.00-L container and the system was allowed to come to equilibrium. The equilibrium concentration of COBr2 was 0.233 M. What is the value of Kc for this reaction? CO (g) + Br2 (g) = COBr2 (g) a. 2.3 b. 5.23 c. 1.16 d. 1.22
A 4.0L reaction flask initially contains 4.0 mol of SO3 at 400K. Sulfur dioxide and oxygen form: 2SO3(g) ⇌ 2SO2(g) + O2(g)After equilibrium is established, 0.27 mol SO3 remain. What is the value of Kc?
Consider the following reaction. A (aq) ⇌ 2B (aq)   Kc = 9.53 x 10-6 at 500 K If a 4.00 M sample of A is heated to 500 K, what is the concentration of B at equilibrium?
For the reaction in the previous problem, that is 2HI (g) <-> H2 (g) + I2(g)        Keq = 0.016 Initially a container contains 0.37 M HI and no product What is the equilibrium concentration of H 2? 
The value of Kc for the thermal decomposition of hydrogen sulfide, shown below, is 2.2 x 10-4 at 1400 K.2H2S (g) → 2H2 (g) + S2 (g) A sample of gas in which [H2S] = 3.05 M is heated to 1400 K in a sealed vessel. After chemical equilibrium has been achieved, what is the value of [H2S]? Assume no H2 or S2 was present in the original sample.
0.6 mol of X is placed in an empty 1.00 L flask and the temperature is raised to 282°C. The following reaction takes place: X (g) ⇌ Y (g) + 3Z (g) At equilibrium, the [Y] = 0.06 M. Determine the equilibrium constant, K, at 282°C. Enter your answer to 3 significant figures and enter a number in scientific notation enter 1 x 10-3 as 1E-3).
Consider the reaction C(s) + CO2(g) ⇌ 2CO(g). When 1.56 mol of CO2 and an excess of solid carbon are heated in a 22.0 L container at 1100K, the equilibrium concentration of CO is 6.74 x 10-2 M. What is the equilibrium concentration of CO2? What is the value of the equilibrium constant Kc at 1100 K?
In air at 25°C and 1.00 atm, the N2 concentration is 0.01 M and the O2 concentration is 0.033 M. The reactionN2(g) + O2(g) ⇌ 2N0(g) has Kc = 4.8 x 10-31 at 25°C.Taking the N2 and O2 concentrations given above as initial values, calculate the equilibrium NO concentration that should exist in our atmosphere from this reaction at 36°C, Kc = 6.4E-30. Make simplifying assumptions in your calculations. (Express your answer in scientific notation.) 
At equilibrium, the concentrations in this system were found to be [N 2] = [O2] = 0.100 M and [NO] = 0.500 M. N2(g) + O2(g) ⇌ 2NO(g) If more NO is added, bringing its concentration to 0.800 M, what will the final concentration of NO be after equilibrium is re-established?
If a solution with initial concentrations of PCl 3 and Cl2 both equaling 2.50 x 10 -3 M before reaction gives an equilibrium concentration of PCl3 of 5.25 x 10 -4 M. What is the equilibrium constant for the reaction? PCl5 <-> PCl3 + Cl2
At a certain temperature, 0.4811 mol of N2 and 1.581 mol of H2 are placed in a 4.00-L container. N2 (g) + 3H2 (g) ⇌  2NH3 (g) At equilibrium, 0.1401 mol of N2 is present. Calculate the equilibrium constant, Kc.
Carbon disulfide is prepared by heating sulfur and charcoal. The chemical equation is S2(g) + C(s) ⇌ CS2(g)          Kc = 9.40 at 900 K How many grams of CS2(g) can be prepared by heating 10.5 moles of S2(g) with excess carbon in a 5.10 L reaction vessel held at 900 K until equilibrium is attained? 
At a certain temperature, 0.4811 mol of N2 and 1.601 mol of H2 are placed in a 2.00-L container. N2 (g) + 3H2 (g) ⇌ 2NH3 (g) At equilibrium, 0.1201 mol of N2 is present. Calculate the equilibrium constant, Kc. 
Initially, 0.680 mol of A is present in a 4.00-L solution. 2A (aq) ⇌ 2B (aq) + C (aq) At equilibrium, 0.200 mol of C is present. Calculate K.
At equilibrium, the concentrations in this system were found to be [N 2] = [O2] = 0.100 M and (NO) = 0.400 M. N2 (g) + O2 (g) ⇌ 2NO (g) If more NO is added, bringing its concentration to 0.700 M, what will the final concentration of NO be after equilibrium is re-established?
Ammonium Iodide dissociates reversibly to ammonia and hydrogen iodide:NH4I(s) ⇋ NH3(g) + HI(g)Kp = 0.215 at 400°CIf 150 g of ammonium iodide is placed into a 3.00 L vessel and heated to 400°C, calculate the partial pressure of ammonia when equilibrium is reached. Hint: Ammonium Iodide is a solid, is it used in the equilibrium calculation? 
Consider the reaction between NO and Cl2 to form NOCl: 2NO(g) + Cl2(g) ⇌ 2NOCl(g)A reaction mixture at a certain temperature initially contains only [NO] = 0.61 M and [Cl2]= 0.61 M. After the reaction comes to equilibrium, the concentration of NOCl is 0.31 M. Find the value of the equilibrium constant (Kc) at this temperature.