The Reaction Quotient

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

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

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

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.    

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.

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.

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

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.

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.

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.  

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 

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.

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.

Consider the following reaction at equilibrium at 24°C:NH4HS(s) ⇌ NH3(g) + H2S(g)      Kc = 1.58 x 10–4If 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?

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 M2. 0.205 M3. 0.295 M4. 0.240 M5. 0.102 M6. 0.429 M7. 0.145 M8. 0.071 M

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

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.  

Consider the following general reaction:2 B4A4 (l) + 2 C2 (g) → 4 A2C (g) + 4 B2 (g),           K c =  0.0596If 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 equilibriumB. Q < K; the reaction will shift towards the reactantsC. Q > K; the reaction will shift towards the productsD. Q > K; the reaction will shift towards the reactantsE. Q < K; the reaction will shift towards the products.

At 500 °C, 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 °C, 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 = KpB. The reaction proceeds to the left towards reactants until  Qp = KpC. The reaction proceeds to the right towards products until  Qp > KpD. The reaction proceeds to the left towards reactants until  Qp < Kp

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

Consider the reactionMg(s) + Fe2+(aq) → Mg2+(aq) + Fe(s) at 75°Cwhere [Fe2+] = 2.90M and [Mg2+] = 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?

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?

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

For the reaction:PCl3 (g) + Cl2 (g) ⇌ PCl5 (g)           K c = 24.3a 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 changeb. the amount of PCl 5 will increasec. more PCl3 will formd. the reaction will shift righte. the amount of PCl 3 will increase while the concentration of Cl 2 will decrease.  

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

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

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.

The value of Kc for the reaction: 2 NO2 (g) ⇌ N2O4(g) is 6.9 at 447 K. Determine the reaction quotient for a mixture of the two gases in which [NO2] = 0.0311 M and [N2O4] = 0.00931 M.