Question

What happens to the concentration of
SO2(g) when the total pressure on the equilibrium reaction
2 SO2(g) + O2(g) <---> 2 SO3(g) is increased (by compression)?

I thought it remained the same but that was incorrect.

Answer 1

Remember what I told you in the last response. Le Chatelier's Principle--with gases-- the system shifts to the side with the fewer moles of gas. There are three moles on the left and 2 on the right. Goes to the right.

Answer 2

but what happens to the concentration of SO2? does it decrease?

Answer 3

It decreases, yes. The amount of moles is the same as the concentration of the compound. It shifts to the right and causing all molecules to shift; therefore it decreases.