Product the shift in equilibrium when the volume is decreased on the following equilibrium reactions: (i) \(\mathrm{Pcl}_{3(\mathrm{~g})}+\mathrm{Cl}_{2(\mathrm{~g})} \rightleftarrows \mathrm{PCl}_{5(\mathrm{~g})}\) (ii) \(\mathrm{N}_{2(g)}+\mathrm{O}_{2(\mathrm{~g})} \rightleftarrows 2 \mathrm{NO}_{(g)}\)

To understand how the equilibrium will shift when volume is decreased, it's essential to identify the ratio of moles of reactants/products for each reaction. (i) In the first reaction: \(\mathrm{Pcl}_{3(g)}+\mathrm{Cl}_{2(g)} \rightleftarrows \mathrm{PCl}_{5(g)}\) There is 1 mole of \(\mathrm{Pcl}_{3(g)}\) and 1 mole of \(\mathrm{Cl}_{2(g)}\) (total of 2 moles) on the left (reactants) side, and 1 mole of \(\mathrm{PCl}_{5(g)}\) on the right (product) side. (ii) In the second reaction: \(\mathrm{N}_{2(g)}+\mathrm{O}_{2(g)} \rightleftarrows 2\mathrm{NO}_{(g)}\) There is 1 mole of \(\mathrm{N}_{2(g)}\) and 1 mole of \(\mathrm{O}_{2(g)}\) (total of 2 moles on the left (reactants) side, and 2 moles of \(\mathrm{NO}_{(g)}\) on the right (product) side.

To predict how the equilibrium will shift upon a decrease in volume, we need to apply Le Chatelier's principle. Decreasing the volume of the container increases the pressure inside the container. (i) For the first reaction, we have more moles of gas on the reactant (left) side. Therefore, when the pressure increases due to a decrease in volume, the system will try to counteract the change by shifting the equilibrium to the side with fewer moles of gas. In this case, the equilibrium will shift to the right (towards the products) to minimize the pressure increase, forming more \(\mathrm{PCl}_{5(g)}\). (ii) For the second reaction, there are equal moles of gas on both sides of the equation (2 moles each). Therefore, when the volume is decreased, and the pressure increases, there will be no significant effect on the equilibrium position. This is because the system has equal moles on both sides, and shifting the equilibrium will not help to counteract the change in pressure.