Question

Why is the boiling point of of pure sodium chloride higher than an aqueous solution of NaCl?

Answer 1

Generally solids have higher boiling point than aqueous solutions for the same compound.

Boiling point = The temprerature at which liquid phase converts into gaseous phase.

aqueous solution of NaCl

In the case of aqueous solution of NaCl, only one step that is heating of aqueous solution of NaCl to convert it into gas.

pure sodium chloride = solid

But in the case of pure sodium chloride, two steps are required.

First, we have to melt the sodim chloride to convert into liquid and then we have to heat it to convert into gas.

So more amount of heat energy is required compared to aqueous solution of NaCl.

Therefore,

boiling point of pure sodium chloride is higher than an aqueous solution of NaCl.