Question

Lecture 19 Equilibrium II Worksheet 1)The equilibrium constant, K c , is 9.8 x 10 5 for H 2 (g) + S (s) H 2 S (g). a.Find the reaction quotient, Q c , if [H 2 ] = 0.762 M and [H 2 S] = 0.483 M . b.Has the process established equilibrium? If not, inwhich direction will it proceed? Justify your answer.

Answer 1

Q = 0.634

This means we have more reactants than products. This will cause the reaction to shift to the right, the side of the products.

We have more H2 gas than H2S. The reaction will shift to the side of H2S

Step-by-step explanation:

Step 1: Data given

Kc = 9.8 * 10^5

[H2]= 0.762 M

[H2S] = 0.483 M

When Q=K, the system is at equilibrium this means there will be no shift to the left nor the right.

When Q<K, we have more reactants than products. This will cause the reaction to shift to the right, the side of the products.

When Q>K, we have more products than reactants. This will cause the reaction to shift to the leftt, the side of the reactants.

Step 2: The balanced equation

H2(g) + S(s) ⇆ H2S(g)

Step 3: Calculate Q

Q = [H2S] / [H2]

Q = (0.483 M) / (0.762 M)

Q = 0.634

Step 4: Calculate the direction

Q = 0.634

K = 9.8 * 10^5

Q <<<< K

This means we have more reactants than products. This will cause the reaction to shift to the right, the side of the products.

We have more H2 gas than H2S. The reaction will shift to the side of H2S

Answer 2

a) Qc = 0.6338

b) Qc < Kc ⇒ the reaction proceeds to the right, towards the products.

Step-by-step explanation:

• H2(g) + S(s) ↔ H2S(g)

∴ Kc = 9.8 E5 = [H2S] / [H2]

a) reaction quotient, Q:

∴ Qc = [H2S] / [H2] = (0.483 M)/(0.762 M) = 0.6338

b) the process is not established equilibrium: Qc < Kc

⇒ The reaction evolves to the right, towards the products