Question

This equilibrium reaction is exothermic:   2SO₂ (g) + O₂ (g) <-> 2SO₃ (g)

(where <-> indicates equilibrium, or double headed arrows)

Le Châtelier's principle predicts that __________ will result in an increase in the number of moles of SO₃(g) in the reaction container.

A) decreasing the liquid level

B) removing some oxygen

C) increasing the pressure

D) increasing the volume of the container

E) decreasing the pressure

Answer 1

option C) Increasing the pressure.

2SO2 (g) + O2(g) <--------> 2 SO3 (g)

A) Le Chatlier doesn't apply to liquids.

B) removing oxygen shift the equilibrium towards reactants. Removal of reactants Shift the equilibrium towards reactant as more reactant needs to be produced to compensate the removal of the reactants.

C) increasing the pressure shift the equilibrium towards the fewer moles of gas. Number of moles of gas in reactant = 3 and the number of moles of gas in product =2

Therefore the equilibrium shift towards the product SO3 (g).

D &E) Increasing the volume of the container will decrease the pressure and the equilibrium equilibrium shift towards more moles of gas. i.e, reactant in this case.