Ch.14 - Chemical EquilibriumWorksheetSee all chapters
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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
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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
Jules Bruno

Equilibrium Expressions

When dealing with chemical equilibrium, there will come a time when you have to set up an ICE chart. An ICE chart should be used when we are missing more than one equilibrium amount for the compounds in our balanced equation. 

Writing equilibrium expressions

In this example question, we have 2 moles of nitrogen monoxide gas reacting with 1 mole of bromine liquid to produce 2 moles of NOBr gas. ICE stands for Initial Change Equilibrium. We’re given an initial amount for this reactant here. The units in an ICE chart can be in molarity if we’re dealing with case C because here C stands for concentration which is molarity or the units can be in atmospheres when we’re dealing with Kp. Here, p stands for pressure which in terms of units would be atmospheres. 

We ignore Br2 because it’s a liquid. In an ICE chart, we ignore solids and liquids. We’re not given an initial amount for our product which is pretty normal. Here in this question, we have to look at these two compounds. Again, we’re ignoring bromine because it’s a liquid. Here I’m giving us the initial amount of the reactant. At equilibrium, I don’t give you any equilibrium amounts for either compound. We’re missing more than one equilibrium amount, Therefore, that’s why we’re setting up an ICE chart. 

Remember, an ICE chart stands for Initial Change Equilibrium. Remember that reactants decrease over time to create products. We lose reactants to create products. Because we’re losing reactants, the sign will be negative. The coefficient here is 2 so that’s why it’s 2x. As we’re creating products, the change is positive because they’re increasing over time. The coefficient here is 2 so that’s why it’s 2x. You bring down everything so that’d be 0.10 - 2x and it’d be here 0 + 2x but we just ignore the zero. That would be our filled out ICE chart. 

From there, you would set up your equilibrium expression. Remember, K which is your equilibrium constant equals products over reactants. This represents our equilibrium expression. Again, we ignore solids and liquids in our ICE chart so the Br2 would be found nowhere within our equilibrium expression. Products over reactants, it’d be NOBr. Here, the coefficient is 2 so that becomes the power here divided by NO. The coefficient is 2 so that’s why it’s squared here as well. At equilibrium, we have these representing those compounds. That’s what we plug in to our equilibrium expression. 

We’d solve for x here to help us figure out the equilibrium amounts for both of those compounds. We need to realize here that on the bottom, we can choose to ignore this minus 2x. We can check to see if it’s significant or not. To test to see if it’s significant or not, we use the 5% approximation method. You would just take your initial concentration which is this 0.10 and you would divide it by the equilibrium constant given to you in this question. Here, I don’t give us an equilibrium amount. Just realize that you would take the initial concentration of 0.10 divided by whatever the Kc or Kp is. If that ratio is greater than 500, then we would be able to ignore this minus 2x on the bottom. It would just drop out and we’d solve for x. 

However, if I do the ratio and initial concentration divided by my equilibrium constant is not greater than 500, then I would keep this minus 2x and I’d have to use the quadratic formula which is right here to solve for x. Just remember, the 5% approximation is a way that we can cheat and avoid the quadratic formula. Another thing we can do is if both my top and bottom are both squared, I can simply take the square root to avoid the quadratic formula as well. Again, you have the 5% approximation method and also you have the square root method. If both the top and bottom are squared, you can just take the square root of both sides and solve for x that way and still avoid the quadratic formula. If neither one of these ways works, then we have to set up the quadratic formula and solve for x that way. 



Jules Bruno

Jules felt a void in his life after his English degree from Duke, so he started tutoring in 2007 and got a B.S. in Chemistry from FIU. He’s exceptionally skilled at making concepts dead simple and helping students in covalent bonds of knowledge.


Additional Problems
Consider the reaction: 2A + B ⇌ A 2B. If the equilibrium constant, Kc, = 12.6 at a certain temp and if the reverse rate constant (kr) = 5.1 x 10 -2 s -1 , calculate the value of the forward rate constant, kf.  
Each of the following diagrams represents a system at equilibrium at three different temperatures. Rank the three diagrams in order of increasing value for K (assume all chemicals are in gas phase). A) (i) < (ii) < (iii) B) (ii) < (iii) < (i) C) (iii) < (ii) < (i) D) (iii) < (i) < (ii) E) (ii) < (i) < (iii)
What is the relationship between the equilibrium constant (K c) of a reaction and the rate constants for the forward (kf) and reverse (k r) reactions? (A) Kc = k f k r (B) Kc = k f / k r (C) Kc = 1/(k f k r) (D) Kc = k f - k r
A mixture of N2 (g) and H2 (g) attained equilibrium at 745 K in the reaction: N2 (g) + 3H2 (g) ⇌ 2NH3 (g). The equilibrium mixture of gases was analyzed and found to contain 7.38 atm H 2 , 2.46 atm N2 , and 0.166 atm NH3 . Calculate the equilibrium constant  Kc for the reaction. R = 0.08206 L•atm/(mol•K) A) 1.4x10-3 B) 2.79x 105 C) 1.49 D) 0.104 E) 61.14  
For the reaction below, which expression is correct for Kc? A. Kc = krev / kfwd B. Kc = kfwd 2/ krev C. Kc = kfwd / krev D. Kc = krev / kfwd2
Consider the following reaction, equilibrium concetrations, and equilibrium constant at a particular temperature. Determine the equilibrium pressure of CO. CO(g) + 2 H2(g) ⇌ CH3OH(I)       Kp = 2.25 x 104 P(H2)eq = 0.52 atm A) 8.3 x 104 atm B) 1.2 x 10-5 atm C) 6.25 x 10-3 atm D) 8.5 x 10-5 atm E) 1.6 x 10-4 atm
What is the value of  Kp for the following reaction at 298 K:A (g) + 3 B2 (g) → 2 C (g)if at equilibrium the partial pressures for A = 0.065 atm, B 2 = 0.46 atm, and C = 0.850 atm.a. 0.00876b. 28.43c. 18.95d. 1.08e. 114.2 
The expression for K for the reaction4NH3(g) + 5O2(g) ⇌ 4NO(g) + 6H 2O(g)at equilibrium is:
Considering the following equilibrium, what is the expression for K?a) [HI]2/[H2]b) [H2][I2]/[HI]c) ([H2][I2])1/2 /[HI]2d) [HI]/ [H2]1/2e) [HI]2/[H2][I2]
Which is the correct equilibrium constant expression for the following reaction?Fe2O3(s) + 3 H2 (g) <==> 2 Fe (s) + 3 H2O (g)a. Kc = [Fe2O3][H2] / [Fe] 2[H2O]3b. Kc = [H2] / [H2O]c. Kc = [H2O]3 / [H2]3d. Kc = [Fe]2[H2O]3 / [Fe2O3][H2]3e. Kc = [H2O]3 / [H2]3
Kc = 2.6 x 108 at 825 K for the reaction2H2(g) + S2(g) ⇌ 2H2S(g)The equilibrium concentration of H2 is 0.0020 M and S2 is 0.0010 M. What is the equilibrium concentration of H2S?10 M0.10 M0.0010 M1.0 M
Consider the following reaction at 388 K2 SO2 (g) + O2 (g) ↔ 2 SO3 (g)At equilibrium the reaction mixture contains 1.28 atm of O 2 and 6.78 atm of SO3. The equilibrium constant, Kp, at this temperature is 46.7. Calculate the equilibrium partial pressure of SO2 .a. 1.14 atmb. 0.877 atmc. 0.769 atmd. 1.30 atme. 1.12 atm
Choose the answer which gives the correct equilibrium constant expression for the reaction shown below. 6 H2(g) + P4(g) ⇌ 4 PH3(g)
Determine the value of Kc for the following reaction if the equilibrium concentrations are as follows:[N2]eq = 3.6 M, [O2]eq = 4.1 M, [N2O]eq = 3.3 x 10-18 M.2N2(g) + O2(g) ⇌ 2N2O(g)A) 2.2 x 10-19B) 4.5 x 1018C) 2.0 x 10-37D) 5.0 x 1036E) 4.9 x 10-17
Choose the answer which gives the equilibrium expression for the aqueous reaction shown below.Si(OCH3)4(aq) + 2 H2O(l) ⇌ SiO2(s) + 4 HOCH3(aq)
Consider the following reaction at a certain temperature. 2H2O (g) ⇌ 2H 2 (g) + O2 (g)An equilibrium mixture of the reaction at that same temperature was found to contain 0.416 M of water vapor, H2O, 0.398 M oxygen gas, O2, and 0.472 M hydrogen gas, H 2. Determine the value of the equilibrium constant, Kc, for this reaction.A. 1.09B. 0.452C. 0.512D. 0.432E. 0.309
Consider the following reaction, equilibrium concentrations, and equilibrium constant at a particular temperature. Determine the equilibrium pressure of CO.CO(g) + 2H2(g) ⇌ CH3OH(l)     Kp = 2.25 x 104P(H2)eq = 0.52 atmA) 8.3 x 104 atmB) 1.2 x 10-5 atmC) 6.25 x 10-3 atmD) 8.5 x 10-5 atmE) 1.6 x 10-4 atm
When glucose, a sugar, reacts fully with oxygen,carbon dioxide and water are produced according to the equation:C6H12O6(s) + 6 O2(g) ⟺ 6 CO2(g) + 6 H2O(l)Write the expression for Kc for this reaction.
Methylamine is a weak base in water according to the equilibriumCH3NH2(aq) + H2O(l) ⇌ CH3NH3+(aq) + OH−(aq)What is the correct expression for the equilibrium constant?
Calculate the equilibrium constant for each of the reactions at 25°C.a. 2Fe+3(aq) + 3Sn(s) → 2Fe(s) + 3Sn +2(aq)b. O2(g) + 2H2O(l) + 2Cu(s) → 4OH-(aq) + 2Cu+2(aq)c. Br2(l) + 2I-(aq) → 2Br-(aq) + I2(s)
On analysis, an equilibrium mixture for the reaction. 2H2S(g) ⇌ 2H2(g) + S2(g)was found to contain 1.0 mol H2S, 4.0 mol H2, and 0.80 mol S2 in a 4.0 L vessel. Calculate the equilibrium constant for this reaction.A. 1.6B. 12.8C. 0.64D. 0.8E. 3.2 
Consider the following reaction:SO2Cl2 ⇋ SO2+Cl2Kp=2.91x103In a reaction at equilibrium, the partial pressure of SO2 is 121 torr and that of Cl2 is 253 torr. Find the partial pressure of SO2Cl2 in this mixture? 
The  equilibrium constant for the reaction                               2 H   2 (g)  +   CO (g) ⇌ CH 3OH (g) is 1.6 x 10-8 at a certain temperature. If there are 1.17 moles of H 2 and 3.46 moles of CH3OH at equilibrium in a 5.60 L flask, how many moles of CO are present at equilibrium? 
Which of the following general classes of substances does not appear in the expression for the equilibrium constant for a reaction?a) pure solidsb) solventsc) solutesd) both a and be) both b and c
Write the equilibrium constant for the following thermal decomposition reaction:2NaHCO3 (s) ⟺ Na2CO3 (s) + CO2 (g) + H2O (g)
For the reaction 2 SO3 (g) ⇌ 2 SO2 (g) + O2 (g), which of the following is the correct equilibrium expression for Kc?A. Kc = [SO3]2 / [SO2]2 [O2]B. Kc = [SO2]2 [O2] / [SO3]2C.Kc = 2 [SO2] [O2] / 2 [SO3]D. Kc = 2 [SO3] / 2 [SO2] [O2]
Express the equilibrium constant for the following reaction.16 CH3Cl(g) + 8 Cl2(g) ⇔ 16 CH2Cl2(g) + 8 H2(g)
What is the equilibrium constant expression Kc for:Al (s) + 3 Ag+ (aq) ⇌ Al3+ (aq) + 3 Ag (s)A. Kc = [Ag+]3 /  [Al3+]B. Kc = [Al3+] / [Ag+]3C. Kc = [Al][Ag+]3/ [Al3+] [Ag]3D. Kc = [Al3+] [Ag]3 /  [Al][Ag+]3
Write the concentration equilibrium constant expression for this reaction.
Which of the following is the correct K b expression for the reaction below:B(aq) + H2O(l) ⇌ HB+ (aq) + OH– (aq)
Consider this reaction.2 SO3 (g) ⇌ 2 SO2 (g) + O2 (g)What is the correct Kp expression for this reaction? 
Consider the reaction C (s) + CO2 (g) → 2 CO(g) .At equilibrium at a certain temperature, the partial pressures of CO(g) and CO2(g) are 1.22 atm and 0.780 atm, respectively. Calculate the value of K for this reaction.1. 1.562. 1.913. 3.134. 0.6405. 2.00
For the reaction,CoO(s) + H 2(g) ⇌ Co(s) + H 2O(g)at 550°C, the value of K is 67.  The equilibrium constant expression is 
Consider this reaction.2 C(s) + O2 (g) ⇌ 2 CO (g)What is the equilibrium expression for this reaction?  
Write the equilibrium-constant expression for the reaction.A (s) + 3B (l) ⇋ 2C (aq) + D (aq)in terms of [A],[B],[C], and [D] as needed.
For the reaction shown here2NH3(g) ⇌ 3H2(g) + N2(g)the equilibrium concentrations were found to be:[NH3]= 0.250M[H2]= 0.420 M[N2]= 0.750 MWhat is the equilibrium constant for this reaction?
Write the equilibrium constant expression for the reaction:  2HgO( s) ⇌ 2Hg(l) + O 2(g)  
Determine the value of Kc for the following reaction if the equilibrium concentrations are as follows:[N2]eq = 3.6 M, [O2]eq = 4.1 M, [N2O]eq = 3.3 × 10-18 M.2 N2(g) + O2(g) ⇌ 2 N2O(g)
Consider the following reaction and its equilibrium constant:                FeO(s) + CO(g) ⇌ Fe(s) + CO2(g)          Keq = 0.67        If the equilibrium concentration of CO is measured at 0.40 M, what is the equilibrium concentration of CO 2?        A)  0.40 M    B)  1.1 M    C)  0.67 M    D)  0.27 M    E)  1.7 M  
For the reaction4PH3(g) ⇌ 6H2O(g) + P4(g)the equilibrium concentrations were found to be[PH3] = 0.250 M[H2O] = 0.430 M[P4] = 0.750 MWhat is the equilibrium constant for this reaction?
Now let’s consider the overall reaction as an equilibrium process, carried out at a lower temperature such that H 2O is obtained as a liquid.2NO(g) + H 2(g) ⇌ N 2O(g) + H 2O(l)Write the equilibrium expression for this reaction. 
Which is the correct equilibrium constant expression for the following reaction?2Fe (s) + 3H2O (g) ⇌ Fe2O3 (s) + 3H2 (g)
Kc = 1.03 x 10-6 for the reaction shown below. if the equilibrium concentrations of H 2 = 0.00463 M and S2 = 0.00684, what is the equilibrium concentration of the H 2S?2H2S(g) ↔ 2H2(g) +S2(g)A. 0.142 MB. 7.02 MC. 2.35 MD. 0.377 ME. 5.54 M
What is the proper form of the equilibrium constant expression for the equation: N  2(g) + O2(g) ⇌ 2NO(g)?
The acid HOCl (hypochlorous acid) is produced by bubbling chlorine gas through a suspension of solid mercury(II) oxide particles in liquid water according to the equation:2HgO(s) + H2O(l) + 2Cl2(g) ⇌ 2HOCl(aq) + HgO(s) + HgCl 2(s)What is the equilibrium constant expression for this reaction?
Identify the proper form of the equilibrium-constant expression for the equationN2(g) + O2(g) ⇌ 2NO(g)a. K = [NO] / [N2][O2]b. K = [NO]2 / [N2][O2]c. K = [N2][O2] / [NO]2d. K = 2[NO] / [N2][O2]
The acid HOCl (hypochlorous acid) is produced by bubbling chlorine gas through a suspension of solid mercury(II) oxide particles in liquid water according to the equation2HgO(s) + H2O(l) + 2Cl2(g) ⇌ 2HOCl(aq) + HgO⋅HgCl 2(s)What is the equilibrium-constant expression for this reaction?a. K = [HOCl]2 /[Cl2] 2b. K = [HOCl] 2[HgO⋅HgCl2] / [Cl2]2[H2O][HgO]2c. K = [HOCl]2 / [Cl2]2d. K = [HOCl]2 [Cl2]2 / [H2O]
A sample of pure carbon dioxide at 500 K undergoes spontaneous decomposition to produce the following reaction:2 CO2 (g) ⇌ 2 CO (g)  +  O2 (g)The equilibrium constant KP is 215. Through the reaction it is shown that the partial pressure of O2 is 0.30 at equilibrium. Calculate the partial pressures of CO and CO2 
What is the equilibrium equation for the following reaction?C 2 H 4 (g) + 3 O 2 (g) ⇌ 2 CO 2 (g) + 2 H 2 O (l) 
Write the equilibrium expression, Kc, for the following chemical reaction equation.2 C6H6(g) + 15 O2(g) ⇋ 12 CO2(g) + 6 H2O(g)
What is the equilibrium  constant, Kc, for an equilibrium mixture for the reaction2 BrCl3(g) ⇋ Br2(g) + 3 Cl2(g)which contains 1.0 mol BrCl3, 2.0 mol Br2 and 6.0 mol Cl2 in a 6.0 L vessel.A)  0.014              B) 108            C) 18              D) 12              E) 432
At a certain temperature, K c equals 1.4 × 10 2 for the reaction:2 CO (g) + O 2 (g) ⇌ 2 CO 2 (g).If a 2.50-L flask contains 0.400 mol of CO 2 and 0.100 mol of O 2 at equilibrium, how many moles of CO are also present in the flask?        A) 0.169 mol           B) 0.028 mol                  C) 0.107 mol                              D) 0.0114 m
When the following reaction is at equilibrium, which of these relationships is  always true?2 NOCl (g)  ⇋ 2 NO (g) + Cl 2 (g) 
The graph shows the varation of concentration with time for this reaction at 25°C3A(aq) ⇌ B(aq) + 2C(aq)What is the value of the equilibrium constant at  t2?
Select the correct equilibrium expression for the following reaction.NaH(s) + H2O(l) → NaOH(aq) + H2(g)
Express the equilibrium constant for the following reaction.P4O10 (s) ⇌ P4 (s) + 5 O2 (g)A) K = [P4][O2]5 / [P4O10]B) K = [P4O10] / [P4][O2]5C) K = [O2] -5D) K = [O2]5E) K = [P4O10] / [P4][O2]1/5
Consider the reaction:2NO(g)+Br2(g)⇌2NOBr(g) Kp=28.4 at 298 KIn a reaction mixture at equilibrium, the partial pressure of NO is 126 torr and that of Br2 is 159torr .What is the partial pressure of NOBr in this mixture?
Carbon reacts with water vapor at elevated temperatures. C(s) + H2O(g) ⇌ CO(g) + H2(g)      Kc = 0.2 at 1000°CWhat is the concentration of CO in an equilibrium mixture with [H 2O] = 0.500 M at 1000°C?
Sodium sulfate 10−hydrate, Na 2SO4∙10H2O, dehydrates according to the equationNa2SO4·10H2O(s) ⇌ Na2SO4(s) + 10H2O(g)        K P = 4.08 x 10−25 at 25°CWhat is the pressure of water vapor at equilibrium with a mixture of Na  2SO4∙10H2O and NaSO4?
The equilibrium constant for the reaction shown here is Kc = 1.3 × 103. A reaction mixture at equilibrium contains [A] = 2.6 × 10−3 M. What is the concentration of B in the mixture?A(g) ⇌ B(g)
Calcium chloride 6−hydrate, CaCl2∙6H2O, dehydrates according to the equationCaCl2·6H2O(s) ⇌ CaCl2(s) + 6H2O(g) KP = 5.09 x 10−44 at 25°CWhat is the pressure of water vapor at equilibrium with a mixture of CaCl  2∙6H2O and CaCl2?
Calculate the number of grams of HI that are at equilibrium with 1.25 mol of H  2 and 63.5 g of iodine at 448 °C.H2 + I2 ⇌ 2HI             K c = 50.2 at 448 °C
Carbon monoxide replaces oxygen in oxygenated hemoglobin according to the reaction: HbO2(aq) + CO(aq) ⇌ HbCO(aq) + O2(aq)Suppose that an air mixture becomes polluted with carbon monoxide at a level of 0.10%. Assuming the air contains 20.0% oxygen, and that the oxygen and carbon monoxide ratios that dissolve in the blood are identical to the ratios in the air, what is the ratio of HbCO to HbO2 in the blood-stream?
Consider the following reaction: H2(g) + I2(g) ⇌ 2HI(g)Complete the following table. Assume that all concentrations are equilibrium concentrations in M.T(oC)  [H2] (M)   [I2] (M) [HI] (M)    Kc25  0.0355  0.0388 0.922   –340- 4.60×10−2  0.390 90.6 445 4.90×10−2  4.72×10−2     – 50.2Find [H2] at 340 oC.
What is the minimum mass of CaCO 3 required to establish equilibrium at a certain temperature in a 6.50-L container if the equilibrium constant (Kc) is 0.050 for the decomposition reaction of CaCO3 at that temperature? CaCO3(s) ⇌ CaO(s) + CO2(g)
Consider the following reaction: H2(g) + I2(g) ⇌ 2HI(g)Complete the following table. Assume that all concentrations are equilibrium concentrations in M.T(oC)  [H2] (M)   [I2] (M) [HI] (M)    Kc25  0.0355  0.0388 0.922   –340- 4.60×10−2  0.390 90.6 445 4.90×10−2  4.72×10−2     – 50.2Find [HI] at 445 oC.
Suppose K = 4.5 x 10 -3 at a certain temperature for the reactionPCl5(g) ⇌ PCl3(g) + Cl2(g)If it is found that the concentration of PCl 5 is twice the concentration of PCl 3, what must be the concentration of Cl2 under these conditions?
For the reaction:3O2(g) ⇌ 2O3(g)K = 1.8 x 10 -7 at a certain temperature. If at equilibrium [O 2] = 0.062 M, calculate the equilibrium  O3 concentration.
Diatomic iodine (I2) decomposes at high temperature to form I atoms according to the reaction: I2(g) ⇌ 2I(g), Kc = 0.011 at 1200 oCIn an equilibrium mixture, the concentration of I2 is 0.18 M. What is the equilibrium concentration of I?
Glauber’s salt, Na2SO4·10H2O, was used by J. R. Glauber in the 17 th century as a medicinal agent. At 25°C, Kp = 4.08×10−25 for the loss of waters of hydration from Glauber’s salt:             Na 2SO4·10H2O(s) ⥫⥬ Na2SO4(s) + 10H2O(g)(a) What is the vapor pressure of water at 25°C in a closed container holding a sample of Na2SO4·10H2O(s)?
An important industrial source of ethanol is the reaction, catalyzed by H 3PO4, of steam with ethylene derived from oil:   C2H4(g) + H2O(g) ⇌ C2H5OH(g)     ΔH°rxn = −47.8 kJ      K c = 9 x 103 at 600. K(a) At equilibrium, PC2H5OH = 200. atm and PH2O = 400. atm. Calculate PC2H4.
The equilibrium constant (Kc) for this reaction is 5.0 at a given temperature. CO(g) + H2O(g) ⇌ CO2(g) + H2(g)(a) On analysis, an equilibrium mixture of the substances present at the given temperature was found to contain 0.20 mol of CO, 0.30 mol of water vapor, and 0.90 mol of H2 in a liter. How many moles of CO2 were there in the equilibrium mixture?
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.
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) (a) At equilibrium, PSO3 = 300. atm and PO2 = 100. atm. Calculate PSO2. 
For the reaction2H2O(g) ⇌ 2H2(g) + O2(g)K = 2.4 x 10 -3 at a given temperature. At equilibrium in a 2.0-L container it is found that [H 2O(g)] = 1.1 x 10 -1 M and [H2(g)] = 1.9 x 10 -2 M. Calculate the moles of O2(g) present under these conditions.
The reaction2NO(g) + Br2(g) ⇌ 2NOBr(g)has Kp = 109 at 25ºC. If the equilibrium partial pressure of Br 2 is 0.0159 atm and the equilibrium partial pressure of NOBr is 0.0768 atm, calculate the partial pressure of NO at equilibrium.
The equilibrium constant (Kc) for this reaction is 5.0 at a given temperature. CO(g) + H2O(g) ⇌ CO2(g) + H2(g)(b) Maintaining the same temperature, additional H2 was added to the system, and some water vapor was removed by drying. A new equilibrium mixture was thereby established containing 0.40 mol of CO, 0.30 mol of water vapor, and 1.2 mol of H2 in a liter. How many moles of CO2 were in the new equilibrium mixture? Compare this with the quantity in part (a), and discuss whether the second value is reasonable. Explain how it is possible for the water vapor concentration to be the same in the two equilibrium solutions even though some vapor was removed before the second equilibrium was established.
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) + 2H 2(g)(b) What is the percent yield of H 2 when an equimolar mixture of CH4 and CO2 with a total pressure of 20.0 atm reaches equilibrium at at 1300. K, at which Kp = 2.626×107?
The methane used to obtain H2 for NH3 manufacture is impure and usually contains other hydrocarbons, such as propane, C3H8. Imagine the reaction of propane occurring in two steps:C3H8(g) + 3H2O(g) ⥫⥬ 3CO(g) + 7H 2(g)             K p = 8.175×1015 at 1200. KCO(g) + H2O(g) ⥫⥬ CO2(g) + H2(g)             K p = 0.6944 at 1200. K(c) When 1.00 volume of C3H8 and 4.00 volumes of H2O, each at 1200. K and 5.0 atm, are mixed in a container, what is the final pressure? Assume the total volume remains constant, that the reaction is essentially complete, and that the gases behave ideally.
The methane used to obtain H2 for NH3 manufacture is impure and usually contains other hydrocarbons, such as propane, C3H8. Imagine the reaction of propane occurring in two steps:C3H8(g) + 3H2O(g) ⥫⥬ 3CO(g) + 7H 2(g)             K p = 8.175×1015 at 1200. KCO(g) + H2O(g) ⥫⥬ CO2(g) + H2(g)             K p = 0.6944 at 1200. K(d) What percentage of the C3H8 remains unreacted?
One mechanism for the synthesis of ammonia proposes that N 2 and H2 molecules catalytically dissociate into atoms:N2(g) ⥫⥬ 2N(g)       log K p = −43.10H2(g) ⥫⥬ 2H(g)       log K p = −17.30(a) Find the partial pressure of N in N 2 at 1000. K and 200. atm.
One mechanism for the synthesis of ammonia proposes that N 2 and H2 molecules catalytically dissociate into atoms:N2(g) ⥫⥬ 2N(g)       log K p = −43.10H2(g) ⥫⥬ 2H(g)       log K p = −17.30(b) Find the partial pressure of H in H2 at 1000. K and 600. atm.
One mechanism for the synthesis of ammonia proposes that N 2 and H2 molecules catalytically dissociate into atoms:N2(g) ⥫⥬ 2N(g)       log K p = −43.10H2(g) ⥫⥬ 2H(g)       log K p = −17.30(c) How many N atoms and H atoms are present per liter?
Consider the following reaction: N2(g) + 3 H2(g) ⇌ 2 NH3(g)Complete the following table. Assume that all concentrations are equilibrium concentrations in M. T (K)  [N2][H2][NH3]Kc5000.1150.1050.439  –5750.110–0.1309.67750.130  0.140  –0.0584  Find [H2] at 575 K.
Consider the following reaction: N2(g) + 3 H2(g) ⇌ 2 NH3(g)Complete the following table. Assume that all concentrations are equilibrium concentrations in M. T (K)  [N2][H2][NH3]Kc5000.1150.1050.439  –5750.110–0.1309.67750.130  0.140  –0.0584  Find [NH3] at 775 K.
Consider the reaction: 2 NO(g) + Br2(g) ⇌ 2 NOBr(g); Kp=28.4 at 298 KIn a reaction mixture at equilibrium, the partial pressure of NO is 121 torr and that of Br2 is 141 torr. What is the partial pressure of NOBr in this mixture?
Consider the reaction: SO2Cl2(g) ⇌ SO2(g) + Cl2(g); Kp = 2.91×103 at 298 KIn a reaction at equilibrium, the partial pressure of SO2 is 0.146 torr and that of Cl2 is 0.351 torr. What is the partial pressure of SO2Cl2 in this mixture?
At 25ºC, Kp ≈  1 x 10 -31 for the reactionN2(g) + O2(g) ⇌ 2NO(g)a. Calculate the concentration of NO, in molecules/cm 3, that can exist in equilibrium in air at 25ºC. In air, PN2 = 0.8 atm and PO2 = 0.2 atm.
The minerals hematite (Fe2O3) and magnetite (Fe3O4) exist in equilibrium with atmospheric oxygen: 4Fe3O4(s) + O2(g) ⇌ 6Fe2O3(s) Kp = 2.5 x 1087 at 298 K(a) Determine PO2 at equilibrium. 
A reaction is represented by this equation: A(aq) + 2B(aq) ⇌ 2C(aq)     K c = 1 × 103(b) Using concentrations ≤1 M, make up two sets of concentrations that describe a mixture of A, B, and C at equilibrium.
A reaction is represented by this equation: 2W(aq) ⇌ X(aq) + 2Y(aq)    K c = 5 × 10−4(b) Using concentrations of ≤1 M, make up two sets of concentrations that describe a mixture of W, X, and Y at equilibrium.
You are a member of a research team of chemists discussing plans for a plant to produce ammonia:   N2(g) + 3H2(g) ⇌ 2NH3(g)(a) The plant will operate at close to 700 K, at which K p is 1.00 x 10−4, and employs the stoichiometric 1/3 ratio of N2/H2. At equilibrium, the partial pressure of NH 3 is 50. atm. Calculate the partial pressures of each reactant and Ptotal.
In the process of cave formation (Section 19.3), the dissolution of CO 2 (equation 1) has a Keq of 3.1 × 10−2, and the formation of aqueous Ca(HCO 3)2 (equation 2) has a Keq of 1 × 10−12. The fraction by volume of atmospheric CO 2 is 4 × 10−4. (a) Find [CO2(aq)] in equilibrium with atmospheric CO 2. 
In the process of cave formation (Section 19.3), the dissolution of CO 2 (equation 1) has a Keq of 3.1 × 10−2, and the formation of aqueous Ca(HCO 3)2 (equation 2) has a Keq of 1 × 10−12. The fraction by volume of atmospheric CO 2 is 4 × 10−4. (b) Determine [Ca2+] arising from (equation 2) given current levels of atmospheric CO 2. 
In the process of cave formation (Section 19.3), the dissolution of CO 2 (equation 1) has a Keq of 3.1 × 10−2, and the formation of aqueous Ca(HCO 3)2 (equation 2) has a Keq of 1 × 10−12. The fraction by volume of atmospheric CO 2 is 4 × 10−4. (c) Calculate [Ca2+] if atmospheric CO2 doubles.
Analysis of the gases in a sealed reaction vessel containing NH 3, N2, and H2 at equilibrium at 400°C established the concentration of N2 to be 1.2 M and the concentration of H 2 to be 0.24 M.N2(g) + 3H2(g) ⇌ 2NH3(g)         Kc = 0.50 at 400°CCalculate the equilibrium molar concentration of NH 3.
Calculate the number of moles of HI that are at equilibrium with 1.25 mol of H  2 and 1.25 mol of I2 in a 5.00−L flask at 448°C.H2 + I2 ⇌ 2HI              K c = 50.2 at 448°C
For the following reaction, Kp = 6.5×104 at 308 K:2NO(g) + Cl2(g) ⥫⥬ 2NOCl(g)At equilibrium, PNO = 0.35 atm and PCl2 = 0.10 atm. What is the equilibrium partial pressure of NOCl(g)?
For the following reaction, Kp = 0.262 at 1000°C: C(s) + 2H2(g) ⥫⥬ CH4(g)At equilibrium, PH2 is 1.22 atm. What is the equilibrium partial pressure of CH 4(g)?
What is the pressure of BrCl in an equilibrium mixture of Cl  2, Br2, and BrCl if the pressure of Cl2 in the mixture is 0.115 atm and the pressure of Br 2 in the mixture is 0.450 atm?Cl2(g) + Br2(g) ⇌ 2BrCl(g)          K P = 4.7 x 10−2
What is the pressure of CO 2 in a mixture at equilibrium that contains 0.50 atm H 2, 2.0 atm of H2O, and 1.0 atm of CO at 990°C?H2(g) + CO2(g) ⇌ H2O(g) + CO(g)        K P = 1.6 at 990°C
A sample of CaCO3(s) is introduced into a sealed container of volume 0.656 L and heated to 1000 K until equilibrium is reached. The Kp for the reaction CaCO3(s) ⇌ CaO(s) + CO2(g) is 3.8 × 10−2 at this temperature. Calculate the mass of CaO(s) that is present at equilibrium.
Cobalt metal can be prepared by reducing cobalt(II) oxide with carbon monoxide.CoO(s) + CO(g) ⇌ Co(s) + CO 2(g)               K c = 4.90 x 10 2 at 550°CWhat concentration of CO remains in an equilibrium mixture with [CO 2] = 0.100 M?
For the reaction shown here:2NH3(g) ⇌  3H2 (g) +N2 (g) the equilibrium concentrations were found to beNH3 =0.250 MH2 =0.540 MN2=0.750 MWhat is the equlibrium constant for this reaction?       
A sample of SO3 is introduced into an evacuated sealed container and heated to 600 K. The following equilibrium is established: 2SO3(g) ⇌ 2SO2(g) + O2(g)The total pressure in the system is found to be 3.0 atm and the mole fraction of O2 is 0.12. Find Kp.
Consider the reaction: aA(g) ⇌ bB(g)Each of the entries in the following table represents equilibrium partial pressures of A and B under different initial conditions. What are the values of a and b in the reaction? PA (atm)  PB (atm) 4.02.02.01.41.01.00.500.710.250.50
Ethene (C2H4) can be halogenated by the following reaction: C2H4(g) + X2(g) ⇌ C2H4X2(g)where X2 can be Cl2 (green), Br2 (brown), or I2 (purple). Examine the three figures below representing equilibrium concentrations in this reaction at the same temperature for the three different halogens.Rank the equilibrium constants for these three reactions from largest to smallest.
The following diagram represents an equilibrium mixture produced for a reaction of the type A + X .Is K greater or smaller than 1 if the volume is 1 L and each atom/molecule in the diagram represents 1 mol?
For the reaction shown here:2H2O(g)  ⇌ 2H2(g)+O2(g)the equilibrium concentrations were found to be:[H2O]=0.250 M[H2]=0.560 M[O2]=0.800 MWhat is the equilibrium constant for this reaction?Keq =?  
The following diagram represents a reaction shown going to completion. Each molecule in the diagram represents 0.1 mol, and the volume of the box is 1.0 L.Calculate the value of Kc.
A sample of solid ammonium chloride was placed in an evacuated chamber and then heated, causing it to decompose according to the following reaction:NH4Cl(s) ⇌ NH3(g) + HCl(g)In a particular experiment, the equilibrium partial pressure of NH 3(g) in the container was 2.9 atm. Calculate the value of Kp for the decomposition of NH4Cl(s) at this temperature.
For the reaction2NO(g) + 2H2(g) ⇌ N2(g) + 2H2O(g)it is determined that, at equilibrium at a particular temperature, the concentrations are as follows: [NO(g)] = 8.1 x 10 -3 M, [H2(g)] = 4.1 x 10 -5 M, [N2(g)] = 5.3 x 10 -2 M, and [H2O(g)] = 2.9 x 10 -3 M. Calculate the value of K for the reaction at this temperature.
At high temperatures, elemental nitrogen and oxygen react with each other to form nitrogen monoxide:N2(g) + O2(g) ⇌ 2NO(g)Suppose the system is analyzed at a particular temperature, and the equilibrium concentrations are found to be [N2] = 0.041 M, [O2] = 0.0078 M, and [NO] = 4.7 x 10 -4 M. Calculate the value of K for the reaction.
At a particular temperature, a 3.0-L flask contains 2.4 moles of Cl 2, 1.0 mole of NOCl, and 4.5 x 10 -3 mole of NO. Calculate K at this temperature for the following reaction: 2NOCl(g) ⇌ 2NO(g) + Cl2(g)
Consider the reaction: A(g) ⇌ 2B(g). The graph plots the concentrations of A and B as a function of time at a constant temperature.What is the equilibrium constant for this reaction at this temperature?
Consider the following reaction at a certain temperature:4Fe(s) + 3O2(g) ⇌ 2Fe2O3(s)An equilibrium mixture contains 1.0 mole of Fe, 1.0 x 10-3 mole of O2, and 2.0 moles of Fe2O3 all in a 2.0-L container. Calculate the value of K for this reaction.
In a study of the reaction3Fe(s) + 4H2O(g) ⇌ Fe3O4(s) + 4H2(g)at 1200 K it was observed that when the equilibrium partial pressure of water vapor is 15.0 torr, the total pressure at equilibrium is 36.3 torr. Calculate the value of Kp for this reaction at 1200 K. (Hint: Apply Dalton’s law of partial pressures.)
Consider the following reaction: CO(g) + 2 H2(g) ⇌ CH3OH(g)An equilibrium mixture of this reaction at a certain temperature was found to have [CO] = 0.110 M , [H2]= 0.114 M , and [CH3OH] = 0.190 M. What is the value of the equilibrium constant (Kc) at this temperature?
Consider the following reaction: NH4HS(s) ⇌ NH3(g) + H2S(g)An equilibrium mixture of this reaction at a certain temperature was found to have [NH3] = 0.282 M and [H2S] = 0.365 M. What is the value of the equilibrium constant (Kc) at this temperature?
Consider the following reaction: N2(g) + 3 H2(g) ⇌ 2 NH3(g)Complete the following table. Assume that all concentrations are equilibrium concentrations in M. T (K)  [N2]left[ {{f{N}}_{f{2}} } ight][H2]left[ {{f{H}}_{f{2}} } ight][NH3]left[ {{f{NH}}_{f{3}} } ight]Kcleft[ {{f{K}}_{f{c}} } ight]5000.1150.1050.439  –5750.110–0.1309.67750.130  0.140  –0.0584  Find Kc at 500 K.
Hydrogen is prepared commercially by the reaction of methane and water vapor at elevated temperatures.CH4(g) + H2 O(g) ⇌ 3H2(g) + CO(g)What is the equilibrium constant for the reaction if a mixture at equilibrium contains gases with the following concentrations: CH4, 0.126 M; H2O, 0.242 M; CO, 0.126 M; H2 1.15 M, at a temperature of 760 °C?
Gaseous ammonia was introduced into a sealed container and heated to a certain temperature:2NH3(g) ⥫⥬ N2(g) + 3H2(g)At equilibrium, [NH3] = 0.0225 M, [N2] = 0.114 M, and [H2] = 0.342 M. Calculate Kc for the reaction at this temperature.
Calculate the value of the equilibrium constant K P for the reaction 2NO(g) + Cl2(g) ⇌ 2NOCl(g) from these equilibrium pressures: NO, 0.050 atm; Cl2, 0.30 atm; NOCl, 1.2 atm.
When heated, iodine vapor dissociates according to this equation:I2(g) ⇌ 2I(g)At 1274 K, a sample exhibits a partial pressure of I 2 of 0.1122 atm and a partial pressure due to I atoms of 0.1378 atm. Determine the value of the equilibrium constant, KP, for the decomposition at 1274 K.
A sample of ammonium chloride was heated in a closed container.NH4 Cl(s) ⇌ NH3(g) + HCl(g)At equilibrium, the pressure of NH3(g) was found to be 1.75 atm. What is the value of the equilibrium constant KP for the decomposition at this temperature?
A sample of pure NO2 is heated to 337 oC, at which temperature it partially dissociates according to the equation2NO2(g) ⇌ 2NO(g) + O2(g)At equilibrium the density of the gas mixture is 0.525 g/L at 0.755 atm. Calculate Kc for the reaction.
What is the correct expression for the equilibrium constant (Kc) for the reaction between carbon and hydrogen gas to form methane shown here?C(s) + 2 H2(g) ⇌ CH4(g)
Among the solubility rules previously discussed is the statement: All chlorides are soluble except Hg2Cl2, AgCl, PbCl2, and CuCl.(a) Write the expression for the equilibrium constant for the reaction represented by the equationAgCl(s) ⇌ Ag+(aq) + Cl−(aq). Is Kc > 1, < 1, or ≈ 1? Explain your answer.
Among the solubility rules previously discussed is the statement: All chlorides are soluble except Hg2Cl2, AgCl, PbCl2, and CuCl.(b) Write the expression for the equilibrium constant for the reaction represented by the equationPb2+(aq) + 2Cl−(aq) ⇌ PbCl2(s). Is Kc > 1, < 1, or ≈ 1? Explain your answer.
Among the solubility rule previously discussed is the statement: Carbonates, phosphates, borates, and arsenates—except those of the ammonium ion and the alkali metals—are insoluble.(a) Write the expression for the equilibrium constant for the reaction represented by the equationCaCO3(s) ⇌ Ca2+(aq) + CO3 2−(aq). Is Kc > 1, < 1, or ≈ 1? Explain your answer.
Express the equilibrium constant for the combustion of propane in the balanced chemical equation: C3H8(g) + 5O2(g) ⇌ 3CO2(g) + 4H2O(g)
The following diagram represents a reaction shown going to completion. Each molecule in the diagram represents 0.1 mol, and the volume of the box is 1.0 L.Choose the equilibrium constant expression for the reaction.
Write an expression for the equilibrium constant (Kc) for the following chemical equation:4 HCl(g) + O2(g) ⇌ 2 H2O(l) + 2 Cl2(g)
Write the equilibrium expression (K) for each of the following gas-phase reactions.a. N2(g) + O2(g)  ⇌  2NO(g)
Write the equilibrium expression (K) for each of the following gas-phase reactions.c. SiH4(g) + 2Cl2(g) ⇌ SiCl4(g) + 2H2(g)
Write the equilibrium expression (K) for each of the following gas-phase reactions.d. 2PBr3(g) + 3Cl2(g) ⇌ 2PCl3(g) + 3Br2(g)
Write the equilibrium expression (Kp) for each of the following gas-phase reactions.c. SiH4(g) + 2Cl2(g) ⇌ SiCl4(g) + 2H2(g)
Write the equilibrium expression (Kp) for each of the following gas-phase reactions.d. 2PBr3(g) + 3Cl2(g) ⇌ 2PCl3(g) + 3Br2(g)
Nitrogen and oxygen react at high temperatures.(a) Write the expression for the equilibrium constant (K c) for the reversible reactionN2(g) + O2(g) ⇌ 2NO(g)                ΔH = 181 kJ
Consider the reaction: N2(g) + 3H2(g) → 2NH3(g)Write the equilibrium constant expression for this reaction.
Write expressions for K and Kp for the following reactions.a. 2NH3(g) + CO2(g) ⇌ N2CH4O(s) + H2O(g)
Write expressions for K and Kp for the following reactions.b. 2NBr3(s) ⇌ N2(g) + 3Br2(g)
Write expressions for K and Kp for the following reactions.c. 2KClO3(s) ⇌ 2KCl(s) + 3O2(g)
Write expressions for K and Kp for the following reactions.d. CuO(s) + H2(g) ⇌ Cu(l) + H2O(g)
Write expressions for Kp for the following reactions.a. 2Fe(s) + 3/2 O2(g)  ⇌ Fe2O3(s)
Write expressions for Kp for the following reactions.b. CO2(g) + MgO(s) ⇌ MgCO3(s)
Water gas, a mixture of H2 and CO, is an important industrial fuel produced by the reaction of steam with red hot coke, essentially pure carbon.(a) Write the expression for the equilibrium constant for the reversible reactionC(s) + H2 O(g) ⇌ CO(g) + H2(g)              ΔH = 131.30 kJ
Write expressions for Kp for the following reactions.d. 4KO2(s) + 2H2O(g)  ⇌ 4KOH(s) + 3O2(g)
Give the general expression for the equilibrium constant of the following generic reaction: aA + bB ⇌ cC + dD.
Identify an expression for the equilibrium constant of each of the following chemical equations.SbCl5(g) ⇌ SbCl3(g) + Cl2(g)
Identify an expression for the equilibrium constant of each of the following chemical equations.2 BrNO(g) ⇌ 2 NO(g) + Br2(g)
Identify an expression for the equilibrium constant of each of the following chemical equations.2 CO(g) + O2(g) ⇌ 2 CO2(g)
Find and fix each mistake in the following equilibrium constant expressions.CO(g) + Cl2(g) ⇌ COCl2(g); K = [CO][Cl2]/[COCl2]large{K_{{ m{eq}}} = frac{{[{ m{CO}}][{ m{Cl}}_2 ]}}{{[{ m{COCl}}_2 ]}}}
The binding of oxygen by hemoglobin (Hb), giving oxyhemoglobin (HbO2), is partially regulated by the concentration of H3O+ and dissolved CO2 in the blood. Although the equilibrium is complicated, it can be summarized as HbO2(aq) + H3 O+(aq) + CO2(g) ⇌ CO2 −Hb−H+ + O2(g) + H2 O(l)(a) Write the equilibrium constant expression for this reaction.
Write an equilibrium expression for each of the following chemical equations involving one or more solid or liquid reactants or products.CO32–(aq) + H2O(l) ⇌ HCO3–(aq) + OH–(aq)
Write an equilibrium expression for each of the following chemical equations involving one or more solid or liquid reactants or products.HF(aq) + H2O(l) ⇌ H3O+(aq) + F–(aq)
Find the mistake in the following equilibrium expression and fix it.PCl5(g) ⇌ PCl3(l) + Cl2(g); Kc = [PCl3][Cl2]/[PCl5]large{K_{{ m{eq}}} = frac{{left[ {{ m{PCl}}_3 } ight]left[ {{ m{Cl}}_2 } ight]}}{{left[ {{ m{PCl}}_5 } ight]}}}
Using data from Appendix C in the textbook, write the equilibrium-constant expression and calculate the value of the equilibrium constant and the free-energy change for these reactions at 298 K .2HBr(g) + Cl2(g)  ⇌  2HCl(g) + Br2(g)Which is the equilibrium-constant expression for this reaction?
The phase diagram for SO2 is shown here.Calculate the equilibrium constant for this reaction at 100 oC.
Consider this reaction.P4 (s) + 6 Cl2 (g) ⇌ 4 PCl3 (g)What is the correct Kc expression for this reaction?  
The equilibrium2NO (g) + Cl2 (g) 2NOCl (g)is established at 500 K. An equilibrium mixture of the three gases has partial pressures of 9.50×10−2 atm , 0.175 atm , and 0.27 atm for NO, Cl2, and NOCl, respectively.Calculate Kp for this reaction at 500.0 K.
An equilibrium mixture of H2, I2 and HI at 458°C contains 1.34 atm of H2, 1.34 atm of I2 and 9.30 atm of HI.What is the equilibrium constant (Kp) for this reaction?a) 31.6b) 48.2c) 64.7d) 78.3e) 92.5
What is the value of the equilibrium constant at 500 °C for the formation of NH  3 according to the following equation?N2(g) + 3H2(g) ⇌ 2NH3(g)An equilibrium mixture of NH3(g), H2(g), and N2(g) at 500 °C was found to contain 1.35 M H 2, 1.15 M N2, and 4.12 × 10−1 M NH3.
Consider the following reaction: H2(g) + I2(g) ⇌ 2HI(g)Complete the following table. Assume that all concentrations are equilibrium concentrations in M.T(oC)  [H2] (M)left[ {{f{H}}_{f{2}} } ight]   [I2] (M) left[ {{f{I}}_{f{2}} } ight] [HI] (M) left[ {{f{HI}}} ight]   Kcleft[ {{f{K}}_{f{c}} } ight]25  0.0355  0.0388 0.922   –340- 4.60×10−2  0.390 90.6 445 4.90×10−2  4.72×10−2     – 50.2Find Kc at 25 oC.
Write the equilibrium-constant expression for the reaction A (s) + 3B (l) ⇌ 2C (aq) + D (aq)in terms of [A], [B], [C), and [D] as needed. 
Consider the following reaction N2 (g) + 3H2 (g) ⇌ 2NH3 (g) Complete the following table. Assume that all concentrations are equilibrium concentrations in M. Part A Find Kc at 500 K. Part B Find [H2] at 575 K. Part C Find [NH3] at 775 K.
Calculate the value of Kp for the equation C (s) + CO2 (g) ⇌ 2CO (g) Kp = ? given that at a certain temperature C (s) + 2H2O (g) ⇌ CO2 (g) + 2H2 (g) Kp1 = 3.23 H2 (g) + CO2 (g) ⇌ H2O (g) + CO (g) Kp2 = 0.651 
Butane exists as two isomers, n−butane and isobutane.KP = 2.5 at 25 °CWhat is the pressure of isobutane in a container of the two isomers at equilibrium with a total pressure of 1.22 atm?
At a temperature of 60 °C, the vapor pressure of water is 0.196 atm. What is the value of the equilibrium constant KP for the transformation at 60 °C?H2 O(l) ⇌ H2 O(g)
Consider the reaction A(g) ⇌ B(g). The images shown here illustrate equilibrium mixtures of A (red) and g (black) at three different temperatures.At which temperature is the equilibrium constant the largest?
Part 1 (1 point) Do not add states of matter to the equilibrium expressions.Write the equilibrium constant expression for the following reaction: N2O (g) + NO2 (g) ⇌ 3NO (g) Part 2 (1 point) Do not add states of matter to the equilibrium expressions.Write the equilibrium constant expression for the following reaction: 2CO (g) + O2 (g) ⇌ 2CO2 (g)
The equilibrium constant is 9.36 x 10-17 at 25 °C. The reaction is endothermic with an enthalpy of 131 kJ/mol. What is the equilibrium constant at 700 °C? Report to three significant digits.
At a given temperature, the elementary reaction A ⇌ B in the forward direction is first order in A with a rate constant of 2.60 x 10-2 S-1. The reverse reaction is first order in B and the rate constant is 9.00 x 10-2 S-1. What is the value of the equilibrium constant for the reaction A ⇌ B at this temperature? What is the value of the equilibrium constant for the reaction B ⇌ A at this temperature?
Gaseous ammonia was introduced into a sealed container and heated to a certain temperature: 2 NH3(g) ⇌ N2(g) + 3 H2(g) At equilibrium, [NH3] = 0.0237 M, [N2] = 0.115 M, and [H2] = 0.345 M. Calculate Kc for the reaction at this temperature.
Enter your answer in the provided box.What is the equilibrium constant for the acid-base reaction between ammonia and acetic acid?
Enter your answer in the provided box.Consider the reaction 2NO (g) + O2 (g) ⇋ 2NO2(g) At a certain temperature, an equilibrium mixture consists of 0.0220 mole O 2, 0.0410 mole NO, and 0.973 mole of NO2. Calculate Kp for the reaction, given that the total pressure is 0.200 atm.
The equilibrium constant for the chemical equation N2(g) + 3H2(g) ⇌ 2NH3(g) is Kp = 13.0 at 191°C. Calculate the value of the Kc for the reaction at 191°C. Kc =
Write the equilibrium constant expression for the reaction in terms of [A), [B], [C], and [D]. 
When Kc is <<1, the equilibrium lies far to the right.a. Trueb. False 
At a certain temperature, a 29.0-L contains holds four gases in equilibrium. Their masses are: 3.5 g SO3, 4.6 g SO2, 24.2 g N2, and 0.98 g N2O. What is the value of the equilibrium constant at this temperature for the reaction of SO2 with N2O to form SO3 and N2 (balanced with lowest whole-number coefficients)?
The elementary reaction 2H2O(g) ⇌ 2H2(g) + O2(g) proceeds at a certain temperature until the partial pressures of H2O, H2, and O2 reach 0.0700 atm, 0.00100 atm, and 0.00150 atm respectively. What is the value of the equilibrium constant at this temperature?
What is the Kc for the following equilibrium at 1000°C, CO (g) + 3H2 (g) ⇌ CH4 (g) + H2O (g) [H2] = 0.25 M, [CO] = 0.60 M, [CH 4] = 1.9 M, and [H2O] = 1.9 M? Express your answer using two significant figures. 
For the reaction N2 (g) + 3H2 (g) ⇌ 2NH3 (g) what is the value of Kc at 500°C if the equilibrium concentrations are as follows: [H 2] = 0.30 M, [N2] = 0.40 M, and [NH3] = 2.2 M? Express the equilibrium constant to two significant figures.
What is the numerator for the equilibrium expression, Kc, for the following chemical equilibrium? Cu2+ (aq) + 4NH3 (aq) = Cu(NH3)42+ (aq) a. [Cu(NH3)42+]b. [Cu2+][NH3]4 c. [Cu(NH3)42+]2 d. [Cu2+][NH3]
Consider the reaction for the Haber synthesis of ammonia: N2(g) + 3H2 (g) → 2NH3 (g). Which of the following is the correct equilibrium expression? (i) Keq = [NH3]/[N2][H2]) (ii) Keq = ([N2][H2]3)/[NH3]2 (iii) Keq = [NH3]2/([N2][H2]3) (iv) Keq = [NH3]3/([N2]2[H2]2)
At a given temperature, the elementary reaction A ⇌ B in the forward direction is first order in A with a rate constant of 3.70 x 10-2 s-1. The reverse reaction is first order in B and the rate constant is 8.00 x 10-2 s-1. What is the value of the equilibrium constant for the reaction A ⇌ B at this temperature? What is the value of the equilibrium constant for the reaction B ⇌ A at this temperature?
Ethyl ethanoate (commonly called ethyl acetate), CH3CO2C2H5, is an important solvent used in nail polish remover, lacquers, adhesives, the manufacture of plastics, and even as a food favoring. It is produced from acetic acid and ethanol by the reaction CH3CO2C2H + C2H5OH ⇌ CH3CO2C2H5 + H2OAt 25°C, Kc = 4.10 for this reaction. In a reaction mixture, the following equilibrium concentrations were observed: [CH3CO2H] = 0.377 M, [H2O] = 0.00818 M, and [CH3CO2C2H5] = 0.924 M What was the concentration of CH3CO2H in the mixture? 
The Keq for the reaction: A + B ⇌ AB is 7 What is the Keq for 3 AB ⇌ 3A + 3B?
At 409 K, this reaction has a Kc value of 0.0845. 2X(g) + 3Y(g) ⇌ 2Z(g)Calculate Kp at 409 K.[Note that the pressure is in units of atmosphere (atm).]
Consider the following elementary reaction: ICl (g) + H2 (g) → HI (g) + HCl (g) Suppose we let k1 stand for the rate constant of this reaction, and k-1 stand for the rate constant of the reverse reaction. Write an expression that gives the equilibrium concentration of HCl in terms of k1, k-1, and the equilibrium concentrations of ICl, H2, and HI.
Write the equilibrium-constant expression for the reaction2 NO(g) + O2(g) ⇌ 2 NO2(g)in terms of [NO], [O2], and [NO2].
Write the equilibrium constant expression for this reaction: C6H10O4(aq) + 2 OH- (aq) → 2 CH3COO-(aq) + C2H6O2(aq)
Be sure to answer all parts. Consider the heterogeneous equilibrium process: C(s) + CO2(g) ⇋ 2CO(g) At 700°C, the total pressure of the system is found to be 1.50 atm. If the equilibrium constant is 1.52, calculate the equilibrium partial pressures of CO and CO2.
For the reaction shown here8H2S (g) ⇌ 8H2(g) + S8(g)the equilibrium concentrations were found to be[H2S] = 0.250 M[H2] = 0.560 M[S8] = 0.750 MWhat is the equilibrium constant for this reaction?
An equilibrium was established for the reaction CO(g) + H2O(g) ⇌ CO2(g) + H2(g) at 500 °C. (This is an industrially important reaction for the preparation of hydrogen.) At equilibrium, the following concentrations were found in the reaction vessel: [CO] = 0.167 M, [H2O] . 0.0387 M, [CO2] = 0.106 M, and [H2] = 0.248 M. What is the value of Kc for this reaction? 
Calculate the value of Kp for the equation C (s) + CO2 (g) ⇌ 2CO (g)                       Kp = ? given that at a certain temperature C (s) + 2H2O (g) ⇌ CO2 (g) + 2H2 (g)     Kp1 = 3.11 H2 (s) + CO2 (g) ⇌ H2O(g) + CO(g)        Kp2 = 0.625
The equilibrium between hemoglobin and oxyhemoglobin in the blood can be represented by the following reaction. Write the form of the equilibrium constant expression. Hb + O2 ⇌ HbO2.  
Phosgene (carbonyl chloride), COCl2, is an extremely toxic gas that is used in manufacturing certain dyes and plastics. Phosgene can be produced by reacting carbon monoxide and chlorine gas at high temperatures: CO(g) + Cl2(g) ⇌ COCl2(g) Carbon monoxide and chlorine gas are allowed to react in a sealed vessel at 460°C. At equilibrium, the concentrations were measured and the following results obtained: What is the equilibrium constant, Kp of this reaction? Express your answer numerically.
Consider the following reaction. CO(g) + H2O(g) ⇌ CO2(g) + H2(g) a. Write the expression for the equilibrium constant. b. Calculate K using the following concentrations of each substance at equilibrium: [CO] = 0.270 M; [H2O] = 0.24 m; [CO2] = 0.45 M; [H2] = 0.60 M.
For the reaction shown here 2NH3(g) ⇌ 3H2(g) + N2(g)the equilibrium concentrations were found to be [NH3] = 0.250 M [H2] = 0.580 M [N2] = 0.750 M What is the equilibrium constant for this reaction?
Write the equilibrium expression for each of the following dissolution reactions: (a) PbCrO4 (s) ⇌ Pb2+ (aq) + CrO42- (aq)(b) Cs2SO4 (s) ⇌ 2Cs+ (aq) + SO42-(aq) (c) Fe(OH)3 (s) ⇌ Fe3+ (aq) + 3OH- (aq)
The equilibrium for the reaction for the decomposition of PCl5 to chlorine and PCl3 is 0.042. PCl5(g) ⇌ PCl3(g) + Cl2(g) If the equilibrium concentrations are [PCl3] = 0.010 M, [Cl2] = 0.10 M, what is the value of [PCl5]? (a) 0.0020 M (b) 0.042 M (c) 0.0010 M (d) 0.010 M (e) 0.024 M
What is the equilibrium constant for the reversible reaction in aqueous medium below given that respective concentrations of A, B, C, and D are 0.0117 M, 0.00440 M, 0.00550 M, and 0.00780 M? 3A + 3B ⇌ 2C + 3DReport your answer to the nearest whole number.
At a certain temperature a 24.0-L contains holds four gases in equilibrium. Their masses are: 3.5 g SO3, 4.6 g SO2, 15.8 g N2, and 0.98 g N2O. What is the value of the equilibrium constant at this temperature for the reaction of SO2 with N2O to form SO3 and N2 (balanced with lowest whole-number coefficients)?
Calculate the value of the equilibrium constant K for the reaction 2D ⇌ A + 2B from the following information A + 2B ⇌ C             Kc = 3.15C ⇌ 2D                   Kc = 0.0485
The decomposition of N2O4 at 25°C, N2O4(g) ⇌ 2NO2(g) has Kc = 4.61 x 10-3. A 1.31 L vessel contained 0.0432 mol N2O4 at equilibrium. What was the concentration of NO2 in the vessel? 
For A + 2B ⇌ 2C           Kc = 2.39For 2C ⇌ D            Kc = 0.160Calculate the value of the equilibrium constant for the reactionD ⇌ A + 2B 
An equilibrium mixture of the following reaction was found to have [SbCl3] = 0.155 M and [Cl2] = 0.0268 M 248 °CWhat is the concentration of SbCl5?SbCl5(g) ⇌ SbCl3(g) + Cl2(g)Keq = 5.4x 10-4 at 248°CExpress your answer using two significant figures.
Consider the following reaction. A (aq) ⇌ 3B (aq)      Kc = 2.78 x 10-6 at 500 K If a 4.50 M sample of A is heated to 500 K, what is the concentration of B at equilibrium?
What is the numerical value of Kc for the following reaction if the equilibrium mixture contains 0.025 M N2O4 and 0.20 M NO2? N2O4 (g) ⇌ 2NO2 (g) Express your answer using two significant figures.
At a certain temperature, the equilibrium constant for the following chemical reaction is 0.00145. At equilibrium, the concentration of AB is 2.725 M, the concentration of BC is 1.625 M, and the concentration of AC is 0.240 M. Calculate the concentration of B at equilibrium. AB (aq) + BC (aq) ⇌ AC (aq) + 2B (aq)
Write an expression for the equilibrium constant for the reaction. 2 NO(g) + O2(g) ⇌ 2 NO2(g)
At 2000 K the partial pressures of an equilibrium mixture of H2S, H2, and S are 0.015, 0.041, and 0.025 atm, respectively. Calculate the value of the equilibrium constant Kp at 2000 K. H2S (g) ⇌ H2 (g) + S (g)
The equilibrium constant, Kc, for the following reaction is 2.01 x 10-2 at 710 K. NH4I (s) ⇌ NH3 (g) + HI (g) Calculate Kc at this temperature for the following reaction: NH3 (g) + HI (g) ⇌ NH4I (s)
Write the equilibrium constant expression for this reaction: H2C2O4 (aq) → 2H+ (aq) + C2O42- (aq) 
The reaction 2PH3 (g) + As2 (g) ⇌ 2AsH3 (g) + P2 (g) has Kp = 2.9 x 10-5 at 873 K. At the same temperature, what is Kp for each of the following reactions? 2AsH3 (g) + P2(g) ⇌ 2PH3 (g) + As2(g) Express your answer using two significant figures. 6PH3(g) + 3As2(g) ⇌ 3P2(g) + 6AsH3(g) Express your answer using two significant figures. 
An equilibrium mixture of the following reaction was found to have [SO3] = 0.411 M and [O2] = 0.205 M at 600 °C What is the concentration of SO2?2SO2 (g)+ O2 (g) ⇌ 2SO3 (g)Keq = 4.14 at 600 °C
For A + 2B ⇌ 2C                Kc = 2.15 For 2C ⇌ D                                             Kc = 0.194 Calculate the value of the equilibrium constant for the reaction D ⇌ A + 2B 
The equilibrium constant, Kc, is calculated using molar concentrations. For gaseous reactions another form of the equilibrium constant, Kp, is calculated from partial pressures instead of concentrations. These two equilibrium constants are related by the equation Kp = Kc (RT)Δn where R = 0.08206 L•atm/(K•mol), T is the absolute temperature, and Δn is the change in the number of moles of gas (sum moles product - sum moles reactants). For example, consider the reaction N2(g) + 3H2(g) ⇌ 2NH3(g)  for which Δn = 2 - (1 + 3) = -2 Part A. For the reaction 3A(g) + 3B(g) ⇌ C(g) Kc = 29.8 at a temperature of 293°C. Calculate the value of Kp. Express your answer numerically. Part B. For the reaction X(g) + 3Y(g) ⇌ 2Z(g) Kp = 3.41 x 10-2 at a temperature of 203°C. Calculate the value of Kc. Express your answer numerically.
For the reaction shown here 2NH3 (g) ⇌ 3 H2 (g) + N2 (g) the equilibrium concentrations were found to be [NH3] = 0.250 M [H2] = 0.540 M [N2] = 0.800 M What is the equilibrium constant for this reaction?
Write the concentration equilibrium constant expression for this reaction.
Nitric oxide and bromine were allowed to react in a sealed container. When equilibrium was reached PNO = 0.526 atm = 1.59 atm, and PNOBr = 12.2 atm. Calculate Kp for the reaction: 2NO (g) + Br2 (g) = 2NOBr (g) Include 3 significant digits.
The elementary reaction 2H2O(g) ⇌ 2H2(g) + O2(g) proceeds at a certain temperature until the partial pressures of H2O, H2, and O2 reach 0.0550 atm, 0.00100 atm, and 0.00400 atm respectively. What is the value of the equilibrium constant at this temperature?
At 327 K, this reaction has a Kc values of 0.0474. X (g) + 3Y (g) ⇌ 2Z (g) Calculate Kp at 327 K. Note that the pressure is in units of atmosphere (atm).
Write the following equilibrium-constant expressions: (a) Kc for Cr (s) + 3Ag+ (aq) ⇌ Cr3+ (aq) + 3Ag (s), (b) Kp for 3Fe (s) + 4H2O(g) ⇌ Fe3O4 (s) + 4H2 (g).
Consider the reaction: 2NH3 (g) ⇌ N2 (g) + 3H2 (g) Select the equilibrium constant expression. (A) Kc = [NH3]2/[N2][H2]3 (B) Kc = [N2]2/[H2][NH3] (C) Kc = [N2][H2]3/[NH3]2 What is the numerical value of Kc for the reaction if the concentrations at equilibrium are 0.19 M NH3, 5.0 M N2, and 0.60 M H2? Express your answer using two significant figures.
Consider the reaction:1/2 N2(g) + O2(g) ⇌ NO2(g)Write the equilibrium constant for this reaction in terms of the equilibrium constants, Ka and Kb for reactions a and b below:a) N2O4(g) ⇌ 2NO2(g)               Kab) N2(g) + 2O2(g) ⇌ N2O4(g)    Kb
What is the equilibrium expression (Kc) for the following reaction? A(aq) + B(aq) → C(aq)