Question

Solid NH₄HS decomposes by the following endothermic process:

a. What effect will adding more (g) have on the equilibrium?

b. What effect will adding more (s) have on the equilibrium?

c. What effect will increasing the volume of the container have on the equilibrium?

d. What effect will decreasing the temperature have on the equilibrium?

Short answer

a. It will shift the reaction to the left to reach equilibrium again.

b. It will have no effect on the equilibrium reaction.

c. It will move the reaction to the right.

d. It will shift the reaction to the left.

Step-by-step solution

Part a.

In order to regain equilibrium, the reaction will move to the left. Adding additional ammonia,${\mathrm{NH}}_3$ will move the equilibrium to the left, allowing part of the extra gaseous product to be used up.

Part b.

The addition of solid${\mathrm{NH}}_4\mathrm{HS}$ will have no effect because in the equilibrium constant expression, the concentration of ${\mathrm{NH}}_4\mathrm{HS}$ is not present in it. Hence, adding more solid has no effect on the equilibrium.

Part c.

According to Stoichiometric equation, the total number of moles of gaseous reactants is zero while the total number of moles of gaseous products is two. Increasing the volume will shift the equilibrium reaction to the right side because more number of moles of gas made to fill the increased volume in order to reach the equilibrium again.

Part d.

The given decomposition reaction is endothermic in nature. So, decreasing temperature will shift the equilibrium reaction to the left to generate more heat energy. Therefore, this will move the reaction to the left side.