Question

1. The equilibrium constant for the reaction 2A ⇌ 3B is 2.3. If the initial concentrations of A and B are [A] = 0.10 M and [B] = 0.050 M, which of the following statements is true?

A. The reaction will proceed to the left because Q > K.

B. The reaction will proceed to the right because Q > K.

C. The reaction will proceed to the left because Q < K.

D. The reaction will proceed to the right because Q < K.

E. The system is at equilibrium.

2. The equilibrium constant is given for two of the reactions below. Determine the value of the missing equilibrium constant.

A (g) + 2 B (g) ⇌ AB₂ (g) K₁ = 59

AB₂ (g) + B (g) ⇌ AB₃ (g) K₂ = ?

A (g) + 3 B (g) ⇌ AB₃ (g) K₃ = 478

3. The reaction below has a K_c value of 61. What is the K_p for this reaction at 500. K?

N₂ (g) + 3 H₂ (g) ⇌ 2 NH₃ (g)

4. Given the following reaction, how could you increase the concentration of products? Select all that apply.

A. Increase volume

B. Decrease volume

C. Increase temperature

D. Decrease temperature

E. Add N₂

F. Remove N₂

5. Consider the following reaction at equilibrium:

2 KClO₃ (s) ⇌ 2 KCl (s) + 3 O₂ (g) ΔH < 0

What happens when the reaction mixture is heated?

A. Reaction shifts right

B. Reaction shifts left

C. There is no effect

D. Additional information is needed.

6.

Does the equilibrium 2 NO(g) + O₂(g) ⇌ 2 NO₂(g) shift to the right (more products) or left (more reactants) if the volume of the reaction vessel is increased?

A. right (more products)

B. left (more reactants)

C. no change

Answer 1

Q= [B]³/ [A]²= (0.05)³/(0.1)² =0.0125

Kc= 2.3 Since Q<Kc, the reaction shifts in a direction of decreasing A. The reaction proceeds to the right. D is the correct answer.

b)

For the reaction A+2Bß-> AB2

K1= [AB₂]/ [A] [B]²   (1) =49

[A][B]²/[AB2] =1/49     (1A)

For the reaction AB2+B ßà AB3, K2= [AB³]/ [AB2][B]   (2)

For the reaction A+3Bß-> AB3, K3= [AB3]/ [A][B]³     =478 (3)

Eq.1A* Eq.3 gives [A][B]²*[AB3]/{ [A][B]³*[AB2]}=478/49=9.755

[AB3]/ [AB2] [B] = 9.755= K2

C)Kp =Kc(RT)deln

deln= moles of products- moles of reactants = 2-4 =-2

Kp =61*(0.08206*500)^-2=0.036235

4. Reaction not given

5.for the reaction 2KClO3---> 2KCl+3O2   delH<0

The reaction is exothermic, when the reactino mixture is heated, the reaction proceeds in the endothermic direction, toward the formation of KClO3. B is the correct answer.

6. for the reaction 2NO+O2---> 2NO2

if the volume is increased, i.e an increase in number of moles, the reaction proceeds in a direction where there is a decrease in number of moles. So more NO2 is formed. A is the correct anwwer.