Question

Which of the following reactions will get affected by increasing the pressure? Also, mention whether change will cause the reaction to go into forward or backward direction.
(i) ${COCl}_2\left(g\right)\rightleftharpoons CO\left(g\right)+{Cl}_2\left(g\right)$
(ii) ${CH}_4\left(g\right)+2S_2\left(g\right)\rightleftharpoons {CS}_2\left(g\right)+2H_{2}S\left(g\right)$
(iii) ${CO}_2\left(g\right)+C\left(s\right)\rightleftharpoons 2CO\left(g\right)$
(iv) $2H_2\left(g\right)+CO\left(g\right)\rightleftharpoons {CH}_{3}OH\left(g\right)$
(v) ${CaCO}_3\left(s\right)\rightleftharpoons CaO\left(s\right)+{CO}_2\left(g\right)$
(vi) $4{NH}_3\left(g\right)+5O_2\left(g\right)\rightleftharpoons 4NO\left(g\right)+6H_{2}O\left(g\right)$

Answer 1

(i) The change in the number of moles of the gaseous species $\Delta n=2-1=1$.
When pressure is increased, the equilibrium reaction is affected. The direction of reaction will shift into backward direction.
(ii)The change in the number of moles of the gaseous species $\Delta n=3-3=0$.
When the pressure is increased, the equilibrium reaction is not affected.
(iii) The change in the number of moles of the gaseous species $\Delta n=2-1=1$.
When pressure is increased, the equilibrium reaction is affected. The direction of reaction will shift into backward direction.
(iv) The change in the number of moles of the gaseous species $\Delta n=1-3=-2$.
When pressure is increased, the equilibrium reaction is affected. The direction of reaction will shift into forward direction.
(v) The change in the number of moles of the gaseous species $\Delta n=1-0=1$.
When pressure is increased, the equilibrium reaction is affected. The direction of reaction will shift into backward direction.
(vi) The change in the number of moles of the gaseous species $\Delta n=10-9=1$.
When pressure is increased, the equilibrium reaction is affected. The direction of reaction will shift into backward direction.