Question

how will the following systems react when an increase in pressure occurs? note all species are gases N2O4<-->2NO2

Answer 1

 N2O4 ↔ 2NO2

The  following system  react as below  when  increase in pressure  occurs

The equilibrium   will  shift towards the left (more N2O4  is produced)

   Explanation

When  pressure increases  the equilibrium  shift toward  the side  of reaction with fewer  moles of gas.

 In the reaction  of N2O4 ↔  2 NO2  there  is only  1  moles   of N2O4  and 2 moles of NO2.

Therefore increase  in pressure led to shift of equilibrium towards the left. ( more N2O4 is produced)