Q.

Liquid ⇌ Vapour (a) If vapour pressure is high, it means equilibrium is in forward side. This is attained when inter molecular forces holding the molecules are of weak nature. Low heat is required to convert liquid into vapour. Thus, (a) is correct. (b) Thus, incorrect. (c) When vapour pressure is high, it means inter molecular forces are weak hence (c) is incorrect. (d) When, vapour pressure is low, inter molecular forces are strong, hence large heat is required thus, (d) is incorrect.