1. H2(g) + l2(g) ⇌ 2HI(g)
In the above equilibrium reaction, volume of gaseous molecules is equal on both sides. So increase or decrease the volume will not affect the equilibrium and there will be no change in the yield of product.
Volume is greater in product side. By decreasing the pressure, volume will increase thus, to get more of product CO2, the pressure should be decreased or volume should be increased.
Volume is lesser in product side. So by increasing the pressure, equilibrium shifts to the product side.
