Answer to Question #103321 in Physical Chemistry for Akshay Kumar

Question

In the following equilibrium, predict the direction of shift of equilibrium for each
condition listed below:
N2
(g) + 3H2
(g) 2NH3
(g) + 92 kJ
i) Addition of H2
ii) increased pressure
iii) lowering of temperature.

Answer 1

$N_2(g) + 3H_2(g)\to 2NH_3(g) + 92 kJ$

By using Le-Chatlier principle,

$i)$ Addition of $H_2$ -

When the concentration of the reactant is increased,the reaction equilibrium will shift forward so as to bring the reaction state to original state.

$ii)$  Increased pressure  -

When the pressure is increased,the reaction will try to reduce the pressure by shifting the side where the number of moles of the gas becomes less.In this case,there are 4 moles in reactant side and 3 in that of product side.

So,the reaction equilibrium will shift toward product side or forward direction.

$iii)$ Lowering of temperature-

When the temperature is lowered,the reaction will try to increase the temperature by shifting the side where the energy is being released.

The given reaction is an example of exothermic reaction,hence,when temperature is lowered,the reaction equilibrium will shift forward in order to increase the temperature.