Question

Why does sodium chloride solution freeze at a lower temperature than water

Answer 1

it is salt so it will freeze at lower temperature

Answer 2

Answer:

Potassium chloride or NaCl has low freezing point because of the colligative property which states that when a solute such as NaCl is added to solvent such as water then according to colligative property  there is an elevation in boiling point and a lowering in freezing point.

Freezing point depends on the inter-molecular force of attraction  between the liquid. When solute NaCl is added to solvent water then it decreases the inter-molecular force of attraction between the molecules hence the freezing point decreases.