Magnesium Carbonate Dissociates to Magnesium Oxide and Carbon Dioxide at Elevated

Multiple Choice

Magnesium carbonate dissociates to magnesium oxide and carbon dioxide at elevated temperatures.
MgCO₃(s)
MgO(s) + CO₂(g)
A reaction vessel contains these compounds in equilibrium at 300°C.What will happen if the volume of the container is reduced by 25% at 300°C?

A) The partial pressure of carbon dioxide present at equilibrium will increase.
B) The partial pressure of carbon dioxide present at equilibrium will decrease.
C) The partial pressure of carbon dioxide at equilibrium will be unchanged.
D) The equilibrium constant will have to decrease to compensate for the decrease in volume.
E) More information is needed in order to make a valid judgment.