Question

Suppose the following exothermic reaction is allowed to reach equilibrium. A(g) + 3B(g) ⇋ 2C(g) + 3D(g)Then we make each of the following changes and allow the reaction to reestablish equilibrium. Tell whether the amount of B present at the new equilibrium will be (i) greater than, (ii) less than, or (iii) the same as the amount of B before the change was imposed.(a) The temperature is decreased while the volume is kept constant; (b) more A is added(c) more C is added(d) a small amount of D is removed;(e) the pressure is increased by decreasing the volume

Answer 1

(a) The temperature is decreased while the volume is kept constant;

Because the reaction is exothermic when we decrease the temperature the equilibrium will shift to the right.

The amount of B will be (ii) less than before the change was imposed.

(b) more A is added

Equilibrium is shifted to the right.

The amount of B will be (ii) less than before the change was imposed.

(c) more C is added

Equilibrium is shifted to the left.

The amount of B will be (i) greater than before the change was imposed.

(d) a small amount of D is removed

Equilibrium is shifted to the right.

The amount of B will be (ii) less than before the change was imposed.

(e) the pressure is increased by decreasing the volume

The equilibrium will shift to the part where we have a lower number of moles which is the left side.

The amount of B will be (i) greater than before the change was imposed.