1) For which one of the following systems at equilibrium, at constant temperature will the doubling of the volume cause a shift to the right? A) $H_{2}(g)+Cl_{2}(s)\rightleftharpoons2HCl(g)$ B) $2CO(g)+O_{2}(g)\rightleftharpoons 2CO_{2}(g)$ C) $N_{2}(g)+3H_{2}(g)\rightleftharpoons2NH_{3}(g)$ D) $PCl_{5} (g)\rightleftharpoons PCl_{3} (g)+ Cl_{2}(g)$ Answer: Option DExplanation:When volume is increased the conc. decreases & the equilibrium shifts in the direction where more moles are formed
