Question

Explain why on addition of 1mol of NaCl to 1litre of water, the boiling point of water increases,

Answer 1

When 1 mole of NaCl was added to water, the resulting solution has lower mole fraction of water and hence lower vapour pressure. So, some heating would be required above the boiling point of pure water to make the vapour pressure of solution equivalent to atmospheric pressure . Hence the boiling point of solution is more than pure solvent(water).

Answer 2

Hey !!

Vapour pressure of the solvent decreases in the presence of non-volatile solute (glucose) hence boiling point increases.

LET ME GIVE YOU DETAILED ANSWER FOR THE BETTER UNDERSTANDING

Addition of non-volatile solute, glucose in water, lowers the vapour pressure of water. As a result boiling point increases.