Answer: they will decrease.
Explanation:
1) The system given is:
N₂O₄(g) ⇄ 2NO₂(g)
2) This question is answered using Le Chatelier's principle.
When
a force or disturbance is introduced into a system in equilibrium, the
system moves in the direction that relieves the system of such
disturbance.
3) In this case when the pressure is increased the system will try to compensate the increase by reducing the number of molecules, which will result in a relief of the pressure.
4) The system can reduce the number of molecules by reacting in the reverse direction, because 2 molecules of NO₂ combine to produce 1 molecule of N₂O₄. The less the number of molecules the less the pressure.
