Question

For the reaction CH4(g) + Cl2(g) ⇌ CH3Cl(g) + HCl(g) + 26.4 kcal predict the effect on the equilibrium (will it shift to the left or right, or will there be no change?) for each of the following changes. Be sure to answer all parts:

(a) The temperature is increased. (select one of the following: 1) equilibrium shifts to the left, 2) equilibrium shifts to the right, or 3) equilibrium does not change

(b) The pressure is increased by decreasing the volume of the container. (select one of the following: 1) equilibrium shifts to the left, right, or does not change

(c) A catalyst is added. (select one of the following: equilibrium shifts to the left, right, or does not change

Answer 1

According to the Le-Charterlier's principle,
(1) If the temperature is raised, reaction will proceed in the direction in which some heat can destroy (absorbed) so that temperature of the system remains constant.
Thus increase in temperature shifts the equilibrium in the forward direction of those reactions which proceed with absorption of heat (endothermic reactions), and in the back ward direction of those reactions which proceed with the evolution of heat (exothermic reactions)
(2) If the pressure is increased, reaction will takes place in a direction which will bring about lowering f pressure. This implies that the equilibrium will shifts in the direction which produces the smaller no. of gas molecules.
(3) If the concentration of reactants is increased or product is removed , the reaction will take place in the forward direction. If the concentration of reactants decreases or increasing the concentration of products the reaction will take place in the backward direction.
(4) Catalyst speeds up both forward & backward reactions to the same extent but does not have any effect on Equilibrium point.
(5)---> When the no. of moles of reactants & products are same the addition of inert gas has no effect
----> for a reaction at constant pressure ,addition of an inert gas will shifts the equilibrium in the direction in
which there is increase in the no . of moles of the gases

For CH4(g) + Cl2(g) ⇌ CH3Cl(g) + HCl(g) + 26.4 kcal

11+1=2 moles. 1+1=2 moles

(a) The temperature is increased.

It is exothermic reaction so increase of temperature favours backward reaction.So (1) equilibrium shifts to the left.

(b) The pressure is increased by decreasing the volume of the since volume doesn't change so upon increase of pressure the equilibrium does not change

(c) A catalyst is added,equilibrium does not change