Ch.14 - Chemical EquilibriumWorksheetSee all chapters
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Sections
Chemical Equilibrium
ICE Chart
Le Chatelier's Principle
The Reaction Quotient
Additional Practice
Equilibrium Expressions
LearnAdditional PracticeSummary

The reaction quotient, Q, is used to determine if our chemical reaction is at equilibrium. 

Equilibrium Determination

Depending on if Q is greater than or less than K our reaction will shift to attain equilibrium by reaching the equilibrium constant K. The direction our reaction shifts determines whether our reactants or products are increasing or decreasing. 

If the reaction quotient Q is equal to the equilibrium constant K then our reaction is at equilibrium. 

When the reaction quotient, Q, is smaller than the equilibrium constant, K, then the reaction shifts in the forward direction to reach equilibrium. 

When the reaction quotient, Q, is larger than the equilibrium constant, K, then the reaction shifts in the reverse direction to reach equilibrium. 

Example #2: Determining the Reaction Quotient

Example #3: Determining Equilibrium Concentrations

Previous SectionLe Chatelier's Principle
Additional Problems
The reaction shown below has Kp = 81.9 at 25°C. I2(g) + Cl2(g) ⇌ 2 ICl(g) A flask contains Pi2 = 0.114 atm, PCl2 = 0.102 atm, and PICl = 0.355 atm. Choose the answer that best describes how this mixture will behave. A) The reaction is at equlibrium, so the concentrations will not vary. B) The reaction is not at equilibrium and will generate more products. C) The reaction is not at equilibrium and will generate more reactants. D) The reaction will not proceed without the addition of a catalyst. E) The rate constant of the reaction is needed to solve this problem.
The reaction A + B ⇌ C + 2D has an equilibrium constant of 3.7 x 10 -3 . Consider a reaction mixture with: [A] = 2.0 x 10-2 M [B] = 1.7 x 10-4 M [C] = 2.4 x 10-6 M [D] = 3.5 x 10-3 M Which of the following statements is definitely true? No conclusions about the system can be made without additional information. The system is at equilibrium. The reverse reaction will occur to a greater extent than the forward reaction until equilibrium is established. The forward reaction will occur to a greater extent than the reverse reaction until equilibrium is established.
Consider the following general reaction: 2 B4A4 (l) + 2 C2 (g) → 4 A2C (g) + 4 B2 (g),           K c =  0.0596 If you have a reaction mixture that contains 0.725 M concentration of each of these substances, in which direction will the reaction proceed? A. Q = K; the reaction mixture is at equilibrium B. Q < K; the reaction will shift towards the reactants C. Q > K; the reaction will shift towards the products D. Q > K; the reaction will shift towards the reactants E. Q < K; the reaction will shift towards the products.
In a reaction mixture containing only reactants, what is the value of Q? A) -1 B) 1 C) ∞ D) 0 E) It cannot be determined without concentrations.
Which of the following statements is TRUE? A) Dynamic equilibrium occurs when the rate of the forward reaction equals the rate of the reverse reaction. B) The equilibrium constant for the forward reaction is equal to the equilibrium constant for the reverse reaction. C) A reaction quotient (Q) larger than the equilibrium constant (K) means that the reaction will favor the production of more products. D) Dynamic equilibrium indicates that the amount of reactants and products are equal. E) All of the above are true.
Consider the following reaction and its equilibrium constant: I2(g) ⇌ 2I(g)                K p = 0.209 A reaction mixture contains 0.89 atm I 2 and 1.77 atm I. Which of the following statements is TRUE concerning this system? A) The reaction will shift in the direction of reactants. B) The reaction quotient will increase. C) The reaction will shift in the direction of products. D) The equilibrium constant will decrease. E) The system is at equilibrium.
A mixture of 0.2 moles of H2S(g), 0.5 moles of S8(s), and 0.35 moles of H2(g) is placed in a 2L container where the equilibrium 8H2S(g) ⇌ 8H2(g) + S8(s) is established. If the equilibrium constant for this reaction is Kc = 162, which of the following statements is true? a) Q = 162 and the reaction is already at equilibrium. b) Q = 44 and the reaction proceeds to the left c) Q = 88 and the reaction proceeds to the right d) Q = 44 and the reaction proceeds to the right e) Q = 88 and the reaction proceeds to the left
Consider the following reaction at equilibrium at 24°C: NH4HS(s) ⇌ NH3(g) + H2S(g)      Kc = 1.58 x 10–4 If 0.0205 mol of NH3(g), 0.00800 mol of H2S, and excess solid NH4HS are mixed in a one-liter container at 24°C, in what direction will the equilibrium proceed?
The reaction 2 NO(g) + Br2(g) ⟺ 2NOBr(g) has an equilibrium constant of 116.6  at 25°C. If Mickey Mouse starts with the reaction mixture PNO = 0.300, PBr2 = 0.225, PNOBr = 0.855 at 25°C, predict what will happen as the reaction proceeds towards equilibrium. The initial partial pressures are given in atm. a) More reactants will form b) More products will form c) The reaction is already at equilibrium d) It is impossible for the process to come to equilibrium from these starting conditions e) Not enough information is given
At 500oC, the Kp for the below reaction is 1.45 x10 -5. When 75 atm N2, 35 atm H2, and 5 atm of NH3 are added to a container and heated to 500 oC, in which direction does the reaction proceed? N2 (g) + 3 H2 (g) ⇌ 2 NH3 (g) A. The reaction proceeds to the right towards products until  Qp=Kp B. The reaction proceeds to the left towards reactants until  Qp=Kp C. The reaction proceeds to the right towards products until  Qp>Kp D. The reaction proceeds to the left towards reactants until  Qp<Kp
For the following chemical reaction: Br 2(g) + Cl2(g) ⇌ 2BrCl(g) At 400 K, the equilibrium constant is K p = 7.0. A closed vessel at 400 K is filled with 1.00 atm of Br2(g), 1.00 atm of Cl2(g), and 2.00 atm of BrCl(g). Use Q p to determine which of the statements below is true. A) At equilibrium, the total pressure in the vessel will be less than the initial total pressure. B) The equilibrium partial pressure of Br 2(g) will be greater than 1.00 atm. C) The reaction will go to completion. D) The equilibrium partial pressure of BrCl(g) will be greater than 2.00 atm. E) The reaction shifts to the left
Which of the following statements is TRUE? A) If Q < K, it means the reverse reaction will proceed to form more reactants. B) If Q > K, it means the forward reaction will proceed to form more products. C) If Q = K, it means the reaction is at equilibrium. D) All of the above are true. E) None of the above are true.  
Suppose we put 1.0 mol of HI(g), 1.0 mol of H 2 (g), and 1 mol of I2 (g) in a 2.0 liter reaction vessel and the following equilibrium is established: 2 HI (g) ⇌ H2 (g) + I2 (g) If Kc = 10 for this reaction at the temperature of the equilibrium mixture, compute the equilibrium concentration of HI. 1. 0.260 M 2. 0.205 M 3. 0.295 M 4. 0.240 M 5. 0.102 M 6. 0.429 M 7. 0.145 M 8. 0.071 M
Give the direction of the reaction, if Q >> 1 A) The forward reaction is favored. B) The reverse reaction is favored. C) cannot be determined. D) If the temperature is raised, then the forward reaction is favored. E) If the temperature is raised, then the reverse reaction is favored.
If a 1.00 L vessel contains 0.010 atm SO3, 0.010 atm O2, and 0.020 atm SO2, is the system at equilibrium with respect to the reaction below? If not, what will happen in order to establish equilibrium? 2 SO2 + O2 ⇌ 2 SO3                   Kp = 0.14
Given the chemical reaction: 4 H3PO4 (aq) ⇌ 6 H2 (g) + 8 O2 (g) + P4 (s)              Kc = 1.35 X 10  −12 Which direction will the reaction move if there is initially 0.25 M H 3PO4, 0.0020 M H2, 0.150 M O2 and 61.94 grams of P4. a. The reaction will move to the right because Q = 2.1 X 10  -21 b. The reaction will move to the right because Q = 4.2 X 10 −21 c. The reaction will move to the left because Q = 2.1 X 10 −21 d. The reaction will move to the left because Q = 4.2 X 10 −21 e. The reaction will move to the right because Q = 0.0012
What is the difference between the reaction quotient, Q, and the equilibrium constant, K, for a given chemical reaction? 
Consider the reversible reaction: 2NO2(g) ⇋ N2O4(g) If the concentrations of both NO2 and N2O4 are 0.016 mol L-1, what is the value of Qc? A)  0.016               B)  0.50           C)  1.0             D)  2.0             E)  63  
The equilibrium constant, Kp , for the reaction:    H2(g) + I2(g)  ⇋ 2HI(g) is 55.2 at 425°C. A rigid cylinder at that temperature contains 0.127 atm of hydrogen, 0.134 atm of iodine, and 1.055 atm of hydrogen iodide. Is the system at equilibrium? A)  Yes. B)  No, the forward reaction must proceed to establish equilibrium. C)  No, the reverse reaction must proceed to establish equilibrium. D)  Need to know the volume of the container before deciding. E)  Need to know the starting concentrations of all substances before deciding.
For the reaction: PCl3 (g) + Cl3 (g) ⇌ PCl5 (g)           K c = 24.3 a system is prepared with [PCl3] = 0.10 M; [Cl 2] = 0.15 M; [PCl 5] = 0.60 M. Which response is correct?  a. the reaction is at equilibrium and concentrations will not change b. the amount of PCl 5 will increase c. more PCl3 will form d. the reaction will shift right e. the amount of PCl 3 will increase while the concentration of Cl 2 will decrease.    
The reaction 2 A → B + C has a Kc of 0.2. The reaction is commenced with initial concentrations [A] = 0.2 M, [B] = 0.2 M and [C] = 0.2 M. In what direction does the reaction occur? 1. Cannot be determined without knowing the temperature. 2. The reaction shifts to the right to reach equilibrium 3. The reaction is already at equilibrium 4. The reaction shifts to the left to reach equilibrium.    
Consider a reaction A2(g) + B2(g) ⇌ 2AB(g), with atoms of A shown in red here and atoms of B shown in blue. If Kc = 1, which system is at equilibrium?
If Qc< Kc, in which direction will a reaction proceed in order to reach equilibrium?
What condition must be satisfied so that Qc=Kc?
If Qc> Kc, how must the reaction proceed to reach equilibrium?
At the start of a certain reaction, only reactants are present; no products have been formed. What is the value of Qc at this point in the reaction?
What is the definition of the reaction quotient (Q) for a reaction? What does Q measure?
What is the value of Q when each reactant and product is in its standard state?
A mixture of water and graphite is heated to 600 K. When the system comes to equilibrium it contains 0.15 mol of H2, 0.15 mol of CO, 0.57 mol of H2O, and some graphite. Some O2 is added to the system and a spark is applied so that the H2 reacts completely with the O2.Find the amount of CO in the flask when the system returns to equilibrium.
For the reaction below Kc = 168C(s) + CO2(g) ⇌ 2CO(g)A mixture contains some C(s), [CO] = 0.50 M and [CO 2] = 0.75 M. Therefore the system willa) Shift to produce more C (s) and CO2 (g) because Q < K.b) Shift to produce more CO because Q < K.c) Shift to produce more C (s) and CO2 (g) because Q > K.d) Shift to produce more CO because Q > K.e) The system is already in equilibrium
Consider the reactionMg(s) + Fe2+(aq) → Mg2+(aq) + Fe(s) at 75°Cwhere [Fe2+] = 2.90M and [Mg 2+] = 0.310Ma. What is the value for the reaction quotient, Q, for the cell?b. What is the value for the temperature, T, in kelvins?
Consider the reaction shown below with its equilibrium constant:            S 2Cl 2(g) + Cl 2(g) --->  2SCl 2(g)  Keq = 4Examine the figure, and determine if the system is at equilibrium. If it is not, in which direction will it proceed to reach equilibrium?    A)    The reaction is at equilibrium.    B)    The reaction is not at equilibrium, it will shift to the left.    C)    The reaction is not at equilibrium, it will shift to the right.    D)    It is not possible to tell if the reaction is at equilibrium.    E)    To reach equilibrium, the value of Keq must change
The value of the equilibrium constant at a given temperature for the reaction:                 2HI(g) ⇌ H2(g) + I2(g)         is 0.200.  If [HI] = 0.200 M, [H 2] = 0.200 M, and [I 2] = 0.200 M, determine if the reaction is at equilibrium. If it is not, in which direction will it proceed to reach equilibrium?     A)    The reaction is at equilibrium.     B)    The reaction is not at equilibrium, it will shift to the left.     C)    The reaction is not at equilibrium, it will shift to the right.     D)    It is not possible to tell if the reaction is at equilibrium.     E)    To reach equilibrium, the value of Keq must change.  
At 850 K the equilibrium constant for the following reaction is K c = 15.2SO2(g) + O2(g) ⇌ 2SO3(g) If we mix the following concentrations of the three gases, predict in which direction the reaction will proceed toward equilibrium: Left, Right, or No Reaction.a. [SO2] = 0.60 M, [O2] = 0.70 M, [SO3] = 0.16 Mb. [SO2] = 0.20 M, [O2] = 0.60 M, [SO3] = 0.60 Mc. [SO2] = 0.10 M, [O2] = 0.20 M, [SO3] = 0.40 M
Consider the reaction at 55°C, where [Fe2+] = 3.80 M and [Mg2+] = 0.310 MMg(s) + Fe2+(aq) → Mg+2(aq) + Fe(s)What is the value for the reaction quotient, Q, for the cell?
Consider the hypothetical reaction below3 A (g) + B (g) ↔ 2 C (g)           Kc = 1.5 x 10-3Which of the following statements is correct if the initial concentrations are [A] = 0.85 M, [B] = 0.36 M, and [C] = 0.005 M.A. At equilibrium, the amount of C will increase.B. At equilibrium, the amount of A will increase.C. At equilibrium, the amount of B will increase and C will increase.D. At equilibrium, the amount of A will increase and B will decrease.E. The reaction is at equilibrium.
Balance the equation and write the reaction-quotient expression, Qc.U (s) + F2 (g) ⇌ UF6 (g)Qc=    ?/?  
For a chemical reaction: Cl 2 (g) + O2 (g) ⇌ 2 ClO (g) has a KP = 0.155, and the initial concentrations are:0.55 atm      Cl 2 0.55 atm      O2 0.45 atm      ClOSolve for the final concentration of Cl 2 in atm:A. 0.098B. 0.12C. 0.42D. 0.65E. 0.67 
Write the reaction quotient for
The equilibrium constant Kc for the reaction 2 NOCl(g) → 2 NO(g) + Cl2(g) is 0.51 at a certain temperature. A mixture of NOCl, NO, and Cl2 with concentrations 1.3,1.2, and 0.60 M, respectively, was introduced into a container at this temperature. Which of the following is true? 1. Cl2(g) is produced until equilibrium is reached. 2. [Cl2 ] = 0.30 M at equilibrium. 3. No apparent reaction takes place.  4. [NOCl] = [NO] = [Cl2 ] at equilibrium. 5. NOCl(g) is produced until equilibrium is reached.
In which direction will the net reaction proceedX(g) + Y(g) ⇌ Z(g)          Kp = 1.00 at 300 Kfor the set of initial condition? [X] = [Y] = [Z] = 1.0 M a) net reaction goes to the leftb) net reaction goes to the rightc) reaction is at equilibrium
Which of the following is TRUE? 1. When the value of Q is large, the equilibrium lies on the product side of the equilibrium reaction. 2. A small value of K means that the equilibrium concentrations of the reactants are small compared to the equilibrium concentration of the products. 3. When the value of K is large, the equilibrium lies on the reactant side of the equilibrium reaction. 4. A large value of K means that the equilibrium concentrations of products are large compared to the equilibrium concentrations of the reactants 5. When the value of K is small, the equilibrium lies on the product side of the equilibrium reaction.
Given the equilibrium constant and initial concentrations in a reaction, predict the direction the reaction will proceed The equilibrium constant is equal to 5.00 at 1300 K for the reaction:2 SO 2 (g) + O 2 (g) ⇌ 2 SO 3 (g). If initial concentrations are [SO 2] = 1.20 M, [O 2] = 0.45 M, and [SO 3] = 1.80 M, the system isA) not at equilibrium and will remain in an unequilibrated state.B) at equilibrium.C) not at equilibrium and will shift to the left to achieve an equilibrium state.D) not at equilibrium and wil shift to the right to achieve an equilibrium state
At a certain temperature, bromine and nitric oxide react to form nitrosyl bromide: Br 2(g) + 2 NO(g) ⇌ 2 NOBr(g). When initial amounts of Br 2, NO, and NOBr are mixed, the concentration of NOBr increases. Which statement below is TRUE? A) K c < Q                                  B) K c = Q                       C) K c > Q         D) More information is needed to make a statement about Kc.
One reaction that occurs in producing steel from iron ore is the reduction of iron(II) oxide by carbon monoxide to give iron metal and carbon dioxide. The equilibrium constant, K p, for the reaction at 1000 K is 0.259. FeO (s) + CO (g) ⇌ Fe (s) + CO 2 (g)                 K p = 0.259 at 1000 K. What is the equilibrium partial pressure of CO at 1000 K if the initial partial pressures are P CO = 1.000 atm and P CO2 = 0.500 atm? A) 1.191                B) 0.121          C) 0.241          D) 0.359          E) 0.191
The research and development unit of a chemical company is studying the reaction of CH4 and H2S, two components of natural gas: CH4(g) + 2H2S(g) ⇌ CS2(g) + 4H2(g) In one experiment, 1.00 mol of CH4, 1.00 mol of CS2, 2.00 mol of H2S, and 2.00 mol of H2 are mixed in a 250-mL vessel at 960 oC. At this temperature, Kc = 0.036. If [CH4] = 5.56 M at equilibrium, what are the equilibrium concentrations of H2?   A) 5.56 M                   B) 1.76 M                    C) 6.44 M                    D) 2.44 M
What is the value of Q when the SrCrO 4 solution contains 2.00 × 10−2 M Sr 2+ and 1.50 × 10−3M CrO42−? Calculate the value of Q.
For the reaction 2A(g) ⇌ B(g), the equilibrium constant is Kp = 0.76. A reaction mixture initially contains 4.0 atm of gas (PA = 2.0 atm and PB = 2.0 ; atm). Which statement is true of the reaction mixture?a) The reaction mixture is at equilibrium.b) The reaction mixture will proceed toward products.c) The reaction mixture will proceed toward reactants.d) It is not possible to determine from the information given the future direction of the reaction mixture.
The solid XY decomposes into gaseous X and Y: XY(s) ⇌ X(g) + Y(g); Kp=4.1 (at 0˚C). If the reaction is carried out in a 22.4 L container, which initial amounts of X and Y will result in the formation of solid XY?a) 5 mol X; 0.5 mol Yb) 2.0 mol X; 2.0 mol Yc) 1 mol X; 1 mol Yd) none of the above
Explain why there may be an infinite number of values for the reaction quotient of a reaction at a given temperature but there can be only one value for the equilibrium constant at that temperature.
Consider the reaction: 2H2S(g) ⇌ 2H2(g) + S2(g), Kp = 2.4 x 10–4 (at 1073 K)A reaction mixture contains 0.113 atm of H2, 0.056 atm of S2, and 0.604 atm of H2S. Determine how these conditions compare to equilibrium conditions.
Consider the reaction and its equilibrium constant: N2O4(g) ⇌ 2NO2(g); Kc = 5.85 x 10–3 (at some temperature)A reaction mixture contains [NO2] = 0.0251 M and [N2O4] = 0.0331 M. Determine the direction in which the reaction will proceed.
At a particular temperature a 2.00-L flask at equilibrium contains 2.80 x 10 -4 mole of N2, 2.50 x 10 -5 mole of O2, and 2.00 x 10 -2 mole of N2O. Calculate K at this temperature for the reaction2N2(g) + O2(g) ⇌ 2N2O(g)If [N2] = 2.00 x 10 -4 M, [N2O] = 0.200 M, and [O2] = 0.00245 M, does this represent a system at equilibrium?
The “filmstrip” represents five molecular scenes of a gaseous mixture as it reaches equilibrium over time:X is purple and Y is orange: X2(g) + Y2(g) ⇌ 2XY(g). (c) If K > 1, is time progressing to the right or to the left? Explain. 
The following equilibrium pressures were observed at a certain temperature for the reactionN2(g) + 3H2(g) ⇌ 2NH3(g)PNH3 = 3.1 x 10 -2 atmPN2 = 8.5 x 10 -1 atmPH2 = 3.1 x 10 -3 atmCalculate the value for the equilibrium constant Kp at this temperature.If PN2 = 0.525 atm, PNH3 = 0.0167 atm, and PH2 = 0.00761 atm, does this represent a system at equilibrium?
Consider the reaction: N2(g) + 3H2(g) → 2NH3(g)Write the equilibrium constant expression for this reaction. If some hydrogen is added, before the reaction shifts, how will the numerator and denominator of the expression compare to the value at equilibrium?
The “filmstrip” represents five molecular scenes of a gaseous mixture as it reaches equilibrium over time:X is purple and Y is orange: X2(g) + Y2(g) ⇌ 2XY(g). (a) Write the reaction quotient, Q, for this reaction.(b) If each particle represents 0.1 mol, find Q for each scene.(c) If K > 1, is time progressing to the right or to the left? Explain.(d) Calculate K at this temperature.
Consider the reaction: N2(g) + 3H2(g) → 2NH3(g)If some hydrogen is added, before the reaction shifts, will Q be larger or smaller than K? Why?
Consider the reaction: N2(g) + 3H2(g) → 2NH3(g)If some hydrogen is added, before the reaction shifts, will the reaction have to shift forward or backward to retain equilibrium? Explain.
The equilibrium constant is 0.0900 at 25ºC for the reaction H2O(g) + Cl2O(g) ⇌ 2HOCl(g)For which of the following sets of conditions is the system at equilibrium? For those that are not at equilibrium, in which direction will the system shift?a. PH2O = 1.00 atm, PCl2O = 1.00 atm, PHOCl = 1.00 atmb. PH2O = 200. torr, PCl2O = 49.8 torr, PHOCl = 21.0 torrc. PH2O = 296 torr, PCl2O = 15.0 torr, PHOCl = 20.0 torr
For the reaction N2O4(g) (g), a reaction mixture at a certain temperature initially contains both N2O4 and NO2 in their standard states. If Kp = 0.15, which statement is true of the reaction mixture before any reaction occurs?(a) Q = K; the reaction is at equilibrium.(b) Q < K; the reaction will proceed to the right.(c) Q > K; the reaction will proceed to the left.
The initial concentration or pressure of reactant and product are given for the following system. Calculate the reaction quotient and determine the direction in which system will proceed to reach equilibrium.(a) 2NH3(g) ⇌ N2(g) + 3H2(g)            K c = 17; [NH 3] = 0.20 M, [N2] = 1.00 M, [H2] = 1.00 M
In what direction will a reaction proceed for each condition? Q < K
In what direction will a reaction proceed for each condition? Q > K
In what direction will a reaction proceed for each condition? Q = K
An equilibrium is established according to the following equationHg2 2+(aq) + NO3 −(aq) + 3H+(aq) ⇌ 2Hg2+(aq) + HNO2(aq) + H2 O(l)    Kc = 4.6What will happen in a solution that is 0.20 M each in Hg 2 2+, NO3 −, H+, Hg2+, and HNO2?(a) Hg2 2+ will be oxidized and NO3 − reduced.(b) Hg2 2+ will be reduced and NO3 − oxidized.(c) Hg2+ will be oxidized and HNO2 reduced.(d) Hg2+ will be reduced and HNO2 oxidized.(e) There will be no change because all reactants and products have an activity of 1.
The initial concentration or pressure of reactant and product are given for the following system. Calculate the reaction quotient and determine the direction in which system will proceed to reach equilibrium.(b) 2NH3(g) ⇌ N2(g) + 3H2(g)       KP = 6.8 × 10 4; initial pressures: NH3 = 3.0 atm, N2 = 2.0 atm, H2 = 1.0 atm
The initial concentration or pressure of reactant and product are given for the following system. Calculate the reaction quotient and determine the direction in which system will proceed to reach equilibrium.(c) 2SO3(g) ⇌ 2SO2(g) + O2 (g)             K c = 0.230; [SO3] = 0.00 M, [SO2] = 1.00 M, [O2] = 1.00 M
Consider the equilibrium4NO2(g) + 6H2 O(g) ⇌ 4NH3(g) + 7O2(g)(b) How must the concentration of NH3 change to reach equilibrium if the reaction quotient is less than the equilibrium constant?
The equilibrium constant for the reaction2Fe3+(aq) + Hg 22+(aq) ⇌ 2Fe2+(aq) + 2Hg2+(aq)is Kc = 9.1 x 10−6 at 298 K.(b) If standard-state concentrations of the reactants and product are mixed, in which direction does the reaction proceed?
Consider the following reaction: NH4HS(s) ⇌ NH3(g) + H2S(g)At a certain temperature, Kc = 8.5 x 10–3. A reaction mixture at this temperature containing solid NH4HS has [NH3] = 0.166 and [H2S] = 0.166. Will more of the solid form or will some of the existing solid decompose as equilibrium is reached?
Silver sulfate dissolves in water according to the following reaction: Ag2SO4(s) ⇌ 2 Ag+(aq) + SO42–(aq), Kc = 1.1 x 10–5 at 298 K.A 1.5-L solution contains 6.55 g of dissolved silver sulfate. If additional solid silver sulfate is added to the solution, will it dissolve?
Nitrogen dioxide dimerizes according to the following reaction: 2 NO2(g) ⇌ N2O4(g); Kp = 6.7298A 2.35-L container contains 0.056 mol of NO2 and 0.085 mol of N2O4 298. Is the reaction at equilibrium? If not, in what direction will the reaction proceed?        
Consider the reaction2NO2 (g) ⇌ N2O4 (g)For each of the following mixtures of reactants and products at 25°C, predict the direction in which the reaction will shift to reach equilibrium. a. PNO2 = PN2O4 = 1.0 atm
Consider the reaction2NO2 (g) ⇌ N2O4 (g)For each of the following mixtures of reactants and products at 25°C, predict the direction in which the reaction will shift to reach equilibrium. b. PNO2 = 0.21 atm, PN2O4 = 0.50 atm
Consider the reaction2NO2 (g) ⇌ N2O4 (g)For each of the following mixtures of reactants and products at 25°C, predict the direction in which the reaction will shift to reach equilibrium. c. PNO2 = 0.29 atm, PN2O4 = 1.6 atm
The oxidation of SO2 is the key step in H2SO4 production:   SO2(g) + ½O2(g) ⇌ SO3(g)  ΔH°rxn = −99.2 kJ(b) How does addition of O2 affect Q? K? 
At 425°C, Kp = 4.18×10−9 for the reaction2HBr(g) ⥫⥬ H2(g) + Br2(g)In one experiment, 0.20 atm of HBr(g), 0.010 atm of H2(g), and 0.010 atm of Br2(g) are introduced into a container. Is the reaction at equilibrium? If not, in which direction will it proceed?
At 100°C, Kp = 60.6 for the reaction2NOBr(g) ⥫⥬ 2NO(g) + Br2(g)In a given experiment, 0.10 atm of each component is placed in a container. Is the system at equilibrium? If not, in which direction will the reaction proceed?
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)At a given temperature, Kp = 2.7. If 0.13 mol of CO, 0.56 mol of H 2O, 0.62 mol of CO2, and 0.43 mol of H2 are put in a 2.0-L flask, in which direction does the reaction proceed?
The initial concentration or pressure of reactant and product are given for the following system. Calculate the reaction quotient and determine the direction in which system will proceed to reach equilibrium.(b) 2NH3(g) ⇌ N2(g) + 3H2(g)   KP = 6.8 × 10 4; initial pressures: NH3 = 2.00 atm, N2 = 10.00 atm, H2 = 10.00 atm
The initial concentration or pressure of reactant and product are given for the following system. Calculate the reaction quotient and determine the direction in which system will proceed to reach equilibrium.(c) 2SO3(g) ⇌ 2SO2(g) + O2(g)        Kc = 0.230; [SO3] = 2.00 M, [SO2] = 2.00 M, [O2] = 2.00 M
The initial concentration or pressure of reactant and product are given for the following system. Calculate the reaction quotient and determine the direction in which system will proceed to reach equilibrium.(d) 2SO3(g) ⇌ 2SO2(g) + O2(g) KP = 6.5 atm; initial pressures: SO2 = 1.00 atm, O2 = 1.130 atm, SO3 = 0 atm
The initial concentration or pressure of reactant and product are given for the following system. Calculate the reaction quotient and determine the direction in which system will proceed to reach equilibrium.(e) 2NO(g) + Cl2(g) ⇌ 2NOCl(g) KP = 2.5 × 103; initial pressures: NO = 1.00 atm, Cl  2 = 1.00 atm, NOCl = 0 atm
Consider the following reaction: H2(g) + I2(g) ⇌ 2HI(g)A reaction mixture at equilibrium at 175 K contains PH2 = 0.958 atm, PI2 = 0.877 atm, and PHI = 0.020 atm. A second reaction mixture, also at 175 K, contains PH2 = PI2 = 0.621 atm, and PHI = 0.106 atm. Is the second reaction at equilibrium?
The initial concentration or pressure of reactant and product are given for the following system. Calculate the reaction quotient and determine the direction in which system will proceed to reach equilibrium.(e) 2NO(g) + Cl2(g) ⇌ 2NOCl(g)     Kc = 4.6 × 104; [NO] = 1.00 M, [Cl2] = 1.00 M, [NOCl] = 0 M
The initial concentration or pressure of reactant and product are given for the following system. Calculate the reaction quotient and determine the direction in which system will proceed to reach equilibrium.(f) N2(g) + O2(g) ⇌ 2NO(g)         K c = 0.050; [N2] = 0.100 M, [O2] = 0.200 M, [NO] = 1.00 M
The initial concentration or pressure of reactant and product are given for the following system. Calculate the reaction quotient and determine the direction in which system will proceed to reach equilibrium.(f) N2(g) + O2(g) ⇌ 2NO(g)     KP = 0.050; initial pressures: NO = 10.0 atm, N 2 = O2 = 5 atm
Determine if the following system is at equilibrium. If not, in which direction will the system need to shift to reach equilibrium?SO2 Cl2(g) ⇌ SO2(g) + Cl2(g)[SO2Cl2] = 0.12 M, [Cl2] = 0.16 M and [SO2] = 0.050 M. Kc for the reaction is 0.078.
The initial concentration or pressure of reactant and product are given for the following system. Calculate the reaction quotient and determine the direction in which system will proceed to reach equilibrium.(d) 2SO3(g) ⇌ 2SO2(g) + O2(g)      KP = 16.5; initial pressures: SO3 = 1.00 atm, SO2 = 1.00 atm, O2 = 1.00 atm
The initial concentration or pressure of reactant and product are given for the following system. Calculate the reaction quotient and determine the direction in which system will proceed to reach equilibrium.(a) 2NH3(g) ⇌ N2(g) + 3H2(g)        Kc = 17; [NH3] = 0.50 M, [N2] = 0.15 M, [H2] = 0.12 M
Balance the following reaction and write its reaction quotient, Qc:(a) NO(g) + O2(g) ⥫⥬ N2O3(g)
Balance the following reaction and write its reaction quotient, Qc:(b) SF6(g) + SO3(g) ⥫⥬ SO2F2(g)
Balance the following reaction and write its reaction quotient, Qc:(c) SClF5(g) + H2(g) ⥫⥬ S2F10(g) + HCl(g)
Balance the following reaction and write its reaction quotient, Qc:(a) C2H6(g) + O2(g) ⥫⥬ CO2(g) + H2O(g)
Balance the following reaction and write its reaction quotient, Qc:(b) CH4(g) + F2(g) ⥫⥬ CF4(g) + HF(g)
Balance the following reaction and write its reaction quotient, Qc:(c) SO3(g) ⥫⥬ SO2(g) + O2(g)
Balance the following reaction and write its reaction quotient, Qc:(a) NO2Cl(g) ⥫⥬ NO2(g) + Cl2(g)
Balance the following reaction and write its reaction quotient, Qc:(b) POCl3(g) ⥫⥬ PCl3(g) + O2(g)
Balance the following reaction and write its reaction quotient, Qc:(c) NH3(g) + O2(g) ⥫⥬ N2(g) + H2O(g)
Balance the following reaction and write its reaction quotient, Qc:(a) O2(g) ⥫⥬ O3(g)
Balance the following reaction and write its reaction quotient, Qc:(b) NO(g) + O3(g) ⥫⥬ NO2(g) + O2(g)
Balance the following reaction and write its reaction quotient, Qc:(c) N2O(g) + H2(g) ⥫⥬ NH3(g) + H2O(g)
Write the expression of the reaction quotient for the ionization of HOCN in water.
Write the reaction quotient expression for the ionization of NH 3 in water.
Balance the following example of heterogeneous equilibria and write the reaction quotient, Qc:(a) Na2O2(s) + CO2(g) ⇌ Na2CO3(s) + O2(g)
Balance the following example of heterogeneous equilibria and write the reaction quotient, Qc:(b) H2O(l) ⇌ H2O(g)
Balance the following example of heterogeneous equilibria and write the reaction quotient, Qc:(c) NH4Cl(s) ⇌ NH3(g) + HCl(g)
Balance the following example of heterogeneous equilibria and write the reaction quotient, Qc:(a) H2O(l) + SO3(g) ⇌ H2SO4(aq)
Balance the following example of heterogeneous equilibria and write the reaction quotient, Qc:(b) KNO3(s) ⇌ KNO2(s) + O2(g)
Balance the following example of heterogeneous equilibria and write the reaction quotient, Qc:(c) S8(s) + F2(g) ⇌ SF6(g)
Balance the following example of heterogeneous equilibria and write the reaction quotient, Qc:(a) NaHCO3(s) ⇌ Na2CO3(s) + CO2(g) + H2O(g)
Balance the following example of heterogeneous equilibria and write the reaction quotient, Qc:(b) SnO2(s) + H2(g) ⥫⥬ Sn(s) + H2O(g)
Balance the following example of heterogeneous equilibria and write the reaction quotient, Qc:(c) H2SO4(l) + SO3(g) ⥫⥬ H2S2O7(l)
The “filmstrip” represents five molecular scenes of a gaseous mixture as it reaches equilibrium over time:X is purple and Y is orange: X2(g) + Y2(g) ⇌ 2XY(g). (a) Write the reaction quotient, Q, for this reaction. 
Balance the following example of heterogeneous equilibria and write the reaction quotient, Qc:(a) Al(s) + NaOH(aq) + H2O(l) ⥫⥬ Na[Al(OH)4](aq) + H2(g)
Consider the reaction and its equilibrium constant: N2O4(g) ⇌ 2NO2(g); Kc = 5.85 x 10–3 (at some temperature)A reaction mixture contains [NO2] = 0.0251 M and [N2O4] = 0.0331 M. Calculate Qc at the given concentrations.
Balance the following example of heterogeneous equilibria and write the reaction quotient, Qc:(b) CO2(s) ⥫⥬ CO2(g)
The “filmstrip” represents five molecular scenes of a gaseous mixture as it reaches equilibrium over time:X is purple and Y is orange: X2(g) + Y2(g) ⇌ 2XY(g). (b) If each particle represents 0.1 mol, find Q for each scene. 
Balance the following example of heterogeneous equilibria and write the reaction quotient, Qc:(c) N2O5(s) ⥫⥬ NO2(g) + O2(g)
Write Qc for the following:(a) Hydrogen chloride gas reacts with oxygen gas to produce chlorine gas and water vapor.
Write Qc for the following:(b) Solid diarsenic trioxide reacts with fluorine gas to produce liquid arsenic pentafluoride and oxygen gas.
Write Qc of the following:(c) Gaseous sulfur tetrafluoride reacts with liquid water to produce gaseous sulfur dioxide and hydrogen fluoride gas.
Isolation of Group 8B(10) elements, used as industrial catalysts, involves a series of steps. For nickel, the sulfide ore is roasted in air: Ni3S2(s) + O2(g) ⇌ NiO(s) + SO2(g). The metal oxide is reduced by the H2 in water gas (CO + H 2) to impure Ni: NiO(s) + H2(g) ⇌ Ni(s) + H2O(g). The CO in water gas then reacts with the metal in the Mond process to form gaseous nickel carbonyl, Ni(s) + CO(g) ⇌ Ni(CO)4(g), which is subsequently decomposed to the metal.(b) Show that the overall Q c is the product of the Q c’s for the individual reactions.
Write Qc of the following:(d) Solid molybdenum(VI) oxide reacts with gaseous xenon difluoride to form liquid molybdenum(VI) fluoride, xenon gas, and oxygen gas.
Write the mathematical expression for the reaction quotient, Q c, for the following reaction:(a) N2(g) + 3H2(g) ⇌ 2NH3(g)
Write the mathematical expression for the reaction quotient, Q c, for the following reaction:(b) 4NH3(g) + 5O2(g) ⇌ 4NO(g) + 6H2 O(g)
Write the mathematical expression for the reaction quotient, Q c, for the following reaction:(c) N2 O4(g) ⇌ 2NO2(g)
Write the mathematical expression for the reaction quotient, Q c, for the following reaction:(d) CO2(g) + H2(g) ⇌ CO(g) + H2 O(g)
Write the mathematical expression for the reaction quotient, Q c, for the following reaction:(e) NH4 Cl(s) ⇌ NH3(g) + HCl(g)
The interhalogen ClF3 is prepared via a two-step fluorination of chlorine gas:Cl2(g) + F2(g) ⥫⥬ ClF(g)ClF(g) + F2(g) ⥫⥬ ClF3(g)(b) Show that the overall Q c equals the product of the Q c’s for the individual steps.
Write the mathematical expression for the reaction quotient, Q c, for the following reaction:(f) 2Pb(NO3)2(s) ⇌ 2PbO(s) + 4NO2(g) + O2(g)
Use the following reaction quotient to write the balanced equation:
Use the following reaction quotient to write the balanced equation:
Write the mathematical expression for the reaction quotient, Q c, for the following reaction:(g) 2H2(g) + O2(g) ⇌ 2H2 O(l)
Write the mathematical expression for the reaction quotient, Q c, for the following reaction:(h) S8(g) ⇌ 8S(g)
Show that the complete chemical equation, the total ionic equation, and the net ionic equation for the reaction represented by the equation KI(aq) + I 2(aq) ⇌ KI3(aq) give the same expression for the reaction quotient. KI3 is composed of the ions K + and I3 −.
Write the mathematical expression for the reaction quotient, Q c, for the following reaction:(a) CH4(g) + Cl2(g) ⇌ CH3 Cl(g) + HCl(g)
Write the mathematical expression for the reaction quotient, Q c, for the following reaction:(b) N2(g) + O2(g) ⇌ 2NO(g)
Write the mathematical expression for the reaction quotient, Q c, for the following reaction:(c) 2SO2(g) + O2(g) ⇌ 2SO3(g)
Write the mathematical expression for the reaction quotient, Q c, for the following reaction:(d) BaSO3(s) ⇌ BaO(s) + SO2(g)
Write the mathematical expression for the reaction quotient, Q c, for the following reaction:(e) P4(g) + 5O2(g) ⇌ P4 O10(s)
Write the mathematical expression for the reaction quotient, Q c, for the following reaction:(f) Br2(g) ⇌ 2Br(g)
Write the mathematical expression for the reaction quotient, Q c, for the following reaction:(g) CH4(g) + 2O2(g) ⇌ CO2(g) + 2H2 O(l)
Write the mathematical expression for the reaction quotient, Q c , for the following reaction:(h) CuSO4 •5H2 O(s) ⇌ CuSO4(s) + 5H2 O(g)
Nitrogen dioxide dimerizes according to the following reaction: 2 NO2(g) ⇌ N2O4(g); Kp = 6.7298A 2.35-L container contains 0.056 mol of NO2 and 0.085 mol of N2O4 298. Calculate Q for the reaction.
Compound A decomposes according to the equation                  A(g) ⥫⥬ 2B(g) + C(g)A sealed 1.00-L container initially contains 1.75×10−3 mol of A(g), 1.25×10−3 mol of B(g), and 6.50×10−4 mol of C(g) at 100°C. At equilibrium, [A] is 2.15×10 −3 M. Find [B] and [C].
The equilibrium constant (Kc) for this reaction is 1.60 at 990 °C:H2(g) + CO2(g) ⇌ H2O(g) + CO(g)Calculate the number of moles of each component in the final equilibrium mixture obtained from adding 1.00 mol of H2, 2.00 mol of CO2, 0.750 mol of H2O, and 1.00 mol of CO to a 5.00-L container at 990 °C.
At 25 °C and at 1 atm, the partial pressures in an equilibrium mixture of N  2O4 and NO2 are PN2O4 = 0.70 atm and PNO2 = 0.30 atm.(b) Calculate the partial pressures of NO2 and N2O4 when they are at equilibrium at 9.0 atm and 25 °C.
For the equilibriumH2S(g) ⥫⥬ 2H2(g) + S2(g)     Kc = 9.0×10−8 at 700°Cthe initial concentrations of the three gases are 0.300 M H 2S, 0.300 M H2, and 0.150 M S2. Determine the equilibrium concentrations of the gases.
At 900ºC, Kp = 1.04 for the reaction CaCO3(s) ⇌ CaO(s) + CO2(g)At a low temperature, dry ice (solid CO 2), calcium oxide, and calcium carbonate are introduced into a 50.0-L reaction chamber. The temperature is raised to 900ºC, resulting in the dry ice converting to gaseous CO2. For the following mixtures, will the initial amount of calcium oxide increase, decrease, or remain the same as the system moves toward equilibrium at 900ºC? b. 780 g CaCO3, 1.00 g CaO, PCO2 = 1.04 atm
At 900ºC, Kp = 1.04 for the reaction CaCO3(s) ⇌ CaO(s) + CO2(g)At a low temperature, dry ice (solid CO 2), calcium oxide, and calcium carbonate are introduced into a 50.0-L reaction chamber. The temperature is raised to 900ºC, resulting in the dry ice converting to gaseous CO2. For the following mixtures, will the initial amount of calcium oxide increase, decrease, or remain the same as the system moves toward equilibrium at 900ºC? c. 0.14 g CaCO3, 5000 g CaO, PCO2 = 1.04 atm
At 900ºC, Kp = 1.04 for the reaction CaCO3(s) ⇌ CaO(s) + CO2(g)At a low temperature, dry ice (solid CO 2), calcium oxide, and calcium carbonate are introduced into a 50.0-L reaction chamber. The temperature is raised to 900ºC, resulting in the dry ice converting to gaseous CO2. For the following mixtures, will the initial amount of calcium oxide increase, decrease, or remain the same as the system moves toward equilibrium at 900ºC? d. 715 g CaCO3, 813 g CaO, PCO2 = 0.211 atm
Ethyl acetate is synthesized in a nonreacting solvent (not water) according to the following reaction:CH3CO2H + C2H5OH ⇌ CH3CO2C2H5 + H2O                K = 2.2Acetic acid    Ethanol      Ethyl acetateFor the following mixtures, will the concentration of H 2O increase, decrease, or remain the same as equilibrium is established?a. [CH3CO2C2H5] = 0.22 M, [H2O] = 0.10 M, [CH3CO2H] = 0.010 M, [C2H5OH] = 0.010 M
Ethyl acetate is synthesized in a nonreacting solvent (not water) according to the following reaction:CH3CO2H + C2H5OH ⇌ CH3CO2C2H5 + H2O                K = 2.2Acetic acid    Ethanol      Ethyl acetateFor the following mixtures, will the concentration of H 2O increase, decrease, or remain the same as equilibrium is established?b. [CH3CO2C2H5] = 0.22 M, [H2O] = 0.0020 M, [CH3CO2H] = 0.0020 M, [C2H5OH] = 0.10 M
Ethyl acetate is synthesized in a nonreacting solvent (not water) according to the following reaction:CH3CO2H + C2H5OH ⇌ CH3CO2C2H5 + H2O                K = 2.2Acetic acid    Ethanol      Ethyl acetateFor the following mixtures, will the concentration of H 2O increase, decrease, or remain the same as equilibrium is established?c. [CH3CO2C2H5] = 0.88 M, [H2O] = 0.12 M, [CH3CO2H] = 0.044 M, [C2H5OH] = 6.0 M
Ethyl acetate is synthesized in a nonreacting solvent (not water) according to the following reaction:CH3CO2H + C2H5OH ⇌ CH3CO2C2H5 + H2O                K = 2.2Acetic acid    Ethanol      Ethyl acetateFor the following mixtures, will the concentration of H 2O increase, decrease, or remain the same as equilibrium is established?d. [CH3CO2C2H5] = 4.4 M, [H2O] = 4.4 M, [CH3CO2H] = 0.88 M, [C2H5OH] = 10.0 M
Ethyl acetate is synthesized in a nonreacting solvent (not water) according to the following reaction:CH3CO2H + C2H5OH ⇌ CH3CO2C2H5 + H2O                K = 2.2Acetic acid    Ethanol      Ethyl acetatee. What must the concentration of water be for a mixture with [CH 3CO2C2H5] = 2.0 M, [CH3CO2H] = 0.10 M, and [C2H5OH] = 5.0 M to be at equilibrium?
When 0.100 mol of CaCO3(s) and 0.100 mol of CaO(s) are placed in an evacuated sealed 10.0-L container and heated to 385 K, PCO2 = 0.220 atm after equilibrium is established:   CaCO3(s) ⇌ CaO(s) + CO2(g) An additional 0.300 atm of CO2(g) is pumped in. What is the total mass (in g) of CaCO 3 after equilibrium is re-established?
Highly toxic disulfur decafluoride decomposes by a freeradical process: S 2F10(g) ⥫⥬ SF4(g) + SF6(g). In a study of the decomposition, S 2F10 was placed in a 2.0-L flask and heated to 100°C; [S 2F10] was 0.50 M at equilibrium. More S 2F10 was added, and when equilibrium was reattained, [S2F10] was 2.5 M. How did [SF4] and [SF6] change from the original to the new equilibrium position after the addition of more S2F10?
At a particular temperature, K = 3.75 for the reaction SO2(g) + NO2(g) ⇌ SO3(g) + NO(g)If all four gases had initial concentrations of 0.800 M, calculate the equilibrium concentrations of the gases.
At a particular temperature, K = 1.00 x 102 for the reactionH2(g) + I2(g) ⇌ 2HI(g)In an experiment, 1.00 mole of H2, 1.00 mole of I2, and 1.00 mole of HI are introduced into a 1.00-L container. Calculate the concentrations of all species when equilibrium is reached.
A study of the water-gas shift reaction (see Problem 17.38) was made in which equilibrium was reached with [CO]  = [H2O] = [H2] = 0.10 M and [C O2] = 0.40 M. After 0.60 mol of H2 is added to the 2.0-L container and equilibrium is re-established, what are the new concentrations of all the components?
Antimony pentachloride decomposes according to this equation:SbCl5(g) ⇌ SbCl3(g) + Cl2(g)An equilibrium mixture in a 5.00-L flask at 448 °C contains 3.85 g of SbCl  5, 9.14 g of SbCl 3, and 2.84 g of Cl2. How many grams of each will be found if the mixture is transferred into a 2.00-L flask at the same temperature?
At 650 K, the reaction MgCO3(s) ⇌ MgO(s) + CO2(g) has Kp = 0.026. A 12.6 L container at 650 K has 1.0 g of MgO(s) and CO2 at P = 0.0260 atm. The container is then compressed to a volume of 0.600 L. Find the mass of MgCO3 that is formed.
A system at equilibrium contains I2(g) at a pressure of 0.27 atm and I(g) at a pressure of 0.26 atm . The system is then compressed to half its volume. Find the pressure of I2 when the system returns to equilibrium.
A system at equilibrium contains I2(g) at a pressure of 0.27 atm and I(g) at a pressure of 0.26 atm . The system is then compressed to half its volume. Find the pressure of I when the system returns to equilibrium.
Consider the following reaction: H2(g) + I2(g) ⇌ 2HI(g)A reaction mixture at equilibrium at 175 K contains PH2 = 0.958 atm, PI2 = 0.877 atm, and PHI = 0.020 atm. A second reaction mixture, also at 175 K, contains PH2 = PI2 = 0.621 atm, and PHI = 0.106 atm. What will be the partial pressure of HI in the second reaction mixture when the reaction reaches equilibrium at 175 K?
The system described by the reaction CO(g) + Cl2(g) ⇌ COCl2(g) is at equilibrium at a given temperature when PCO = 0.31 atm, PCl2 = 0.12 atm, and PCOCl2 = 0.61 atm. An additional pressure of Cl2(g) = 0.41 atm is added. Find the pressure of CO when the system returns to equilibrium.
An equilibrium mixture contains N2O4 (P = 0.29 atm) and NO2 (P = 1.2 atm) at 350 K. The volume of the container is doubled at constant temperature. Calculate the equilibrium pressure of NO2 when the system reaches a new equilibrium.
An equilibrium mixture contains N2O4 (P = 0.29 atm) and NO2 (P = 1.2 atm) at 350 K. The volume of the container is doubled at constant temperature. Calculate the equilibrium pressure of N2O4 when the system reaches a new equilibrium.
Hydrogen iodide decomposes according to the reaction2HI(g) ⥫⥬ H2(g) + I2(g)A sealed 1.50-L container initially holds 0.00623 mol of H 2, 0.00414 mol of I 2, and 0.0244 mol of HI at 703 K. When equilibrium is reached, the concentration of H2(g) is 0.00467 M. What are the concentrations of HI(g) and I2(g)?
The following reaction has KP = 4.50 × 10−5 at 720 K. N2(g) + 3H2(g) ⇌ 2NH3(g) If a reaction vessel is filled with each gas to the partial pressures listed, in which direction will it shift to reach equilibrium? P(NH3) = 93 atm, P(N2) = 48 atm, and P(H2) = 52
The value of Kc for the reaction: 2NO2 (g) ⇌ N2O4(g) is 6.9 at 447 K. Determine the reaction quotient for a mixture of the two gases in which [NO  2] = 0.0311 M and [N2O4] = 0.00931 M.
Hydrogen lodide gas is formed when hydrogen and iodine gases are combined. H2 (g) + I2 (g) ⇌ 2HI (g)     Keq = 7.1 x 102 at 25°CA student is studying this reaction to observe how the equilibrium changes. He mixes the proper amounts of the gases so that the initial concentration of hydrogen gas is 0.90 M, the initial concentration of the lodine gas is 0.45 M and the initial concentration of hydrogen lodide gas is 0.75 M. Is the system at equilibrium, or will it shift toward the product? Set up the correct expression that will help you answer this question.Choose one: (i) Q = (0.75 M)2/(0.45M)(0.90M) where the reaction progresses toward the product (ii) Q = 1/(0.45M)(0.90M) 8 1090 where the reaction progresses toward the product (iii) Q = (0.75 M)2/(0.45M)(0.90M) where the reaction is at equillbrium (iv) KC = (0.75 M)2/(0.45M)(0.90M) where the reaction progresses toward the product 
Is a mixture of 0.0205 mol NO2(g) and 0.750 mol N2O4(g) and 0.750 mol N2O4(g) in a 5.25 - L flask at 25 ° C at equilibrium ? If not, in which direction will the reaction proceed - toward products or reactants?N2O4(g)⇌ 2NO2(g) KC = 4.61x10-3 at 25 °Ca. The reaction will proceed to the right, toward productsb. The reaction will proceed to the left, toward reactants.c. The mixture is at equilibrium.
Determine Qc, if the following amounts (in moles) of each component is placed in a 10.00 L container.CO2 0.990 CO 0.480 O2 0.590 
Predict and calculate the effect of concentration changes on an equilibrium system. Some SbCl5 is allowed to dissociate into SbCl3, and Cl2 at 521 K. At equilibrium, [SbCl5] = 0.163 M, and [SbCl3] = [Cl2] = 6.39 x 10-2 M. Additional SbCl5 is added so that [SbCl5]new = 0.287 M and the system is allowed to once again reach equilibrium. SbCl5 (g) ⇌ SbCl3 (g) + Cl2 (g) K = 2.50 x 10-2 at 521 K (a) In which direction will the reaction proceed to reach equilibrium? (b) What are the new concentrations of reactants and products after the system reaches equilibrium? 
Calculate the equilibrium concentrations of N2O4 and NO2 at 25 °C if the initial concentrations are [N2O4] = 0.0180 M and [NO2] = 0.0410 M. The equilibrium constant Kc for the reaction N2O4 (g) ⇌ 2NO2 (g) is 4.64 x 10-3 at 25 °C. Part ACalculate the equilibrium concentration of N2O4. Express your answer with the appropriate units. Part BCalculate the equilibrium concentration of NO2. Express your answer with the appropriate units.
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.(b) Given that PO2, in air is 0.21 atm, in which direction will the reaction proceed to reach equilibrium?                (i) no change                 (ii) toward products                 (iii) toward reactants
At 850 K the equilibrium constant for the following reaction is Kc = 15.2SO2(g) + O2(g) ⇌ 2SO3(g)If we mix the following concentrations of the three gases, predict in which direction the net reaction will proceed toward equilibrium.[SO2] = 0.20 M[O2] = 0.60 M[SO3] = 0.60 M[SO2] = 0.14 M[O2] = 0.10 M[SO3] = 0.40 M[SO2] = 0.90 M[O2] = 0.50 M[SO3] = 0.10 M
Consider this equilibrium reaction at 400 K. Br2 (g) + Cl2 (g) ⇌ 2BrCl (g)        Kc = 7.0 If the composition of the reaction mixture at 400 K is [BrCl] = 0.00415 M, [Br2] = 0.00366 M, and [Cl2] = 0.000672 M, what is the reaction quotient, Q? How is the reaction quotient related to the equilibrium constant, Kc, for this reaction?            (i) Q < K            (ii) Q > K           (iii) Q = K
The equilbrium constant for the water-gas shift reaction is 5.0 at 400 °C: CO(g) + H2O(g) <—> CO2(g) + H2(g) Determine Qc, if the following amounts (in moles) of each component is placed in a 1.0 L container. CO 0.61 H2O 0.40 CO2 0.77 H2 0.64
The equilibrium constant for the following reaction is 0.16 M 0.5 at 3000 K: CO2 (g) <-> CO (g) + 0.5O2(g) Determine Qc if the following amounts (in moles) of each component is placed in a 3.00 L container. CO2 0.790 CO 0.410 O2 0.580 Give answer to 3 decimal places.
For the reaction 2A(g) ⇌ B(g), the equilibrium constant is Kp = 0.76. A reaction mixture initially contains 4.0 atm of gas (PA = 2.0 atm and PB = 2.0 atm). Which statement is true of the reaction mixture? (a) The reaction mixture will proceed toward products. (b) The reaction mixture is at equilibrium. (c) The reaction mixture will proceed toward reactants (d) It is not possible to determine from the information given the future direction of the reaction mixture.
What is the name of Qc?a. Reversibility expressionb. Reaction expressionc. Mass actiond. Equilibrium expressione. Reaction quotient 
Consider this system at equilibrium.A(aq) ⇌ B(aq)        ΔH = +550 kJ/molWhat can be said about Q and K immediately after an increase in temperature?A) Q > K because Q increasedB) Q > K because K decreasedC) Q < K because Q decreasedD) Q < K because K increasedE) Q = K because neither changed How will the system respond to a temperature increase?A) shift leftB) shift rightC) no change
Will a precipitate form if the metal ion concentration in a solution of M(CIO2)3 is 0.0246 M and the concentration of CIO2 is 0.0148 M? Ksp for M(ClO2)3 = 6.25x10-8 Which of the following substances has the higher molar entropy (assume that each is in the gas phase)? 
Sulfur dioxide reacts with chlorine at 227°C: SO2(g) +Cl2(g) <—> SO2Cl2(g) Kp for this reaction is 5.1 x 10-2 atm-1. Initially, 1.00 g each of SO2 and Cl2 are placed in a 1.00 L reaction vessel. After 15 minutes, the concentration of SO2Cl2 is 45.5 μg/mL. You will determine if the system has reached equilibrium. First, what is Kc, (in L/mol)? (A μg is 10-6 g.) Next determine all initial concentrations. What is the initial sulfur dioxide concentration (in mol/L or M)? Determine all concentrations after 15 minutes. What is the chlorine concentration? What is Q after 15 minutes? 
2NO (g) + 2H2 (g) → N2 (g) + 2H2O (g) At the temperature the engineer picks, the equilibrium constant Kp for this reaction is 0.052. The engineer charges ("fills") four reaction vessels with nitrogen monoxide and hydrogen, and lets the reaction begin. He then measures the composition of the mixture inside each vessel from time to time. His first set of measurements are shown in the table below. Predict the changes in the compositions the engineer should expect next time he measures the compositions.
The diagram shows the free energy change of the reaction A(g) + B(g) ⇌ C(g).The reaction progress starts on the left with pure reactants, A and B  each at 1 atm and moves to pure product, C, also at 1 atm on the right. Place the statements in the appropriate place on the diagram.spontaneousnonspontaneousQ< KQ> KQ= K.
Consider this system at equilibrium.A(aq) ⇌ B(aq)        ΔH = -750 kJ/molWhat can be said about Q and K immediately after an increase in temperature?A) Q > K because Q increasedB) Q > K because K decreasedC) Q < K because Q decreasedD) Q < K because K increasedE) Q = K because neither changed How will the system respond to a temperature increase?A) shift leftB) shift rightC) no change
Balance the equation and write the reaction quotient expression. U(s) + F2(g) ⇌ UF6(g)