Question

Would increasing the volume of the container for each of the following reactions at equilibrium cause the system to shift in the direction of the products or the reactants?

Part A
2NH3(g)???3H2(g)+N2(g)

A. Increasing the volume will shift the system in the direction of the products.
B. Increasing the volume will shift the system in the direction of the reactants.
C. Increasing the volume will not shift the equilibrium.

Part B
N2(g)+O2(g)???2NO(g)

A. Increasing the volume will shift the system in the direction of the products.
B. Increasing the volume will shift the system in the direction of the reactants.
C. Increasing the volume will not shift the equilibrium.

Part C
N2(g)+2O2(g)???2NO2(g)

A. Increasing the volume will shift the system in the direction of the products.
B. Increasing the volume will shift the system in the direction of the reactants.
C. Increasing the volume will not shift the equilibrium.

Part D
4NH3(g)+3O2(g)???2N2(g)+6H2O(g)

A. Increasing the volume will shift the system in the direction of the products.
B. Increasing the volume will shift the system in the direction of the reactants.
C. Increasing the volume will not shift the equilibrium.

Part E.

The equilibrium constant, Kc, for the decomposition of N2O4 is 4.6

Answer 1

In general : Decreased volume shifts the system to the side of the reaction that has fewer moles of gas

Or increased volume shifts the system to the side of the reaction that has more moles of gas

Part A

2NH3(g)???3H2(g)+N2(g)

moles of products > moles of reactant

Increasing the volume will shift the system in the direction of the products.

Part B
N2(g)+O2(g)???2NO(g)

moles of products = moles of reactant

Increasing the volume will not shift the equilbrium

Part C
N2(g)+2O2(g)???2NO2(g)

moles of products < moles of reactant

Increasing the volume will shift the system in the direction of the reactant.

Part D
4NH3(g)+3O2(g)???2N2(g)+6H2O(g)

moles of products > moles of reactant

Increasing the volume will shift the system in the direction of the products.

Part E

N2O4(g) -->2NO2(g)

Kc = [NO2]^2 / [N2O4] = 4.6