Question

Consider the following system at equilibrium where K_c = 0.159 and delta H° = -111 kJ/mol at 723 K.

N₂(g) + 3 H₂(g) = 2 NH₃(g)

The production of NH₃(g) is favored by:

Indicate True (T) or False (F) for each of the following:

___TF 1. increasing the temperature.
___TF 2. decreasing the pressure (by changing the volume).
___TF 3. increasing the volume.
___TF 4. adding NH₃.
___TF 5. removing H₂.

Answer 1

The reversible reaction is

N2+ 3H2 = 2NH3 ∆H=-111kj Temperature is 723K

Equilibrium constant Kc is 0 .159

The production of ammonia will increase by

1. Increasing temperature (False) .

Since it is a exothermic reaction (∆H=-111kj ) hence according to Lechatelier's principle for exothermic reaction the equilibrium can shift more forward direction by decreasing temperature.

2.decreasing pressure by changing volume (false).This is because here the forward direction voume is decreasing hence increase of pressure will increase NH3 production according to Lechatelier's principle.

3.increasing volume of system.(false).

Here in the forward direction voume decrease ,hence by decreasing volume ,production of ammonia will increase.

4. By addition of NH3 .( False) Here according to Lechatelier's principle addition of NH3 equilibrium Will shift towards backward direction to maintain equilibrium. So production of NH3 decrease.

5.removing H2.(false) ,If we remove H2 then equilibrium Will shift more towards backward direction to maintain new equilibrium. Hence NH3 production will decrease.