Which of the following statements are correct
a) the boiling point of a solution is greater than pure solvent.
b) the temperature where the vapour pressure of liquid equals to atmospheric pressure is called its boiling point.
c) the vapour pressure of pure solvent is less than the vapour pressure of solution containing non volatile solute.
d) evaporation of a liquid is exothermic

Addition of non volatile solute to a volatile solvent decreases the VP of the solvent

i.e VP of a solution containing a non-volatile solute is lesser than that of pure solvent
    

Lowering of VP $\propto$ Elevation of BP

$\therefore$BP of sol. will be greater than BP of pure solvent

The temperature at which VP of a liquid becomes equal to external pressure is called BP.

Evaporation of liquid is endothermic.