Explain why on addition of 1 mol of NaCl to 1 litre of water, the boiling point of water increases, while addition of 1 mol of methyl alcohol to one litre of water decreases its boiling point.

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Solution

Methyl alcohol is more volatile than water. But

NaCl is non-volatile solute. On addition of NaCl

in water , vapour pressure is lowered and as a

result boiling point of water increased. But on

addition of methyl alcohol ,vapour pressure is

more than that of water. Hence boiling point

decreases.

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Explain why on addition of 1 mole of NaCl to 1L of water, the boiling point of water increases, while addition of 1 mole of methyl alcohol to 1 L of water decreases its boiling point.

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Explain why on addition of 1 mol of NaCl to 1 litre of water, the boiling point of water increases, while addition of 1 mol of methyl alcohol to one litre of water decreases its boiling point.

Methyl alcohol is more volatile than water. But NaCl is non-volatile solute. On addition of NaCl in water , vapour pressure is lowered and as a result boiling point of water increased. But on addition of methyl alcohol ,vapour pressure is more than that of water. Hence boiling point decreases.