Question

Match the effects on the concentration of SO3 gas when the following changes occur after initial equilibrium has been established in this system (N.C. = no change).

2SO2(g) + O2(g) 2SO3(g) + 46.8 kcal

pressure increases
increase

increase [O2]

increase volume of chamber

adding a catalyst

raising the temperature

Answer 1

This is not a multiple choice question. It is asking for the effects on the SO3 concentration after each change is applied.

For each change, think about Le Chatelier’s principle and how the reaction will respond to the applied change.

Staring with pressure increases, because there are fewer moles of gas on the product side, the reaction will shift towards the product side and thus the concentration of SO3 will increase.

Go through each of the other choices and think about how the reaction is affected and how that will affect the SO3 concentration.