Effect on Reaction Rate

Question

I was told when O2 gas is added into this reaction, the reaction rate will increase.

3H2(g) + N2 (g) ----> 2NH3 (g)

Using collision theory to explain this, I assume these particles are in a fixed volume container,

when the container is getting crowded, chances of collision between H2 and N2 is higher?

Is that right?

Answer 1

Adding O2 gas will not participate in the reaction per se, but it will increase the pressure in the container (assuming it is a fixed volume situation). According to Le Chatelier, this will shift the equilibrium to the right since there are more moles of gas on the left.