How will the vapor pressure of an aqueous solution of sodium chloride compare to that of pure water?

Vapor pressure of the solution will be less than the pure water.

Explanation:

Vapor pressure of a liquid is defined as the equilibrium pressure of the vapor above the liquid. It is also the pressure exerted by the evaporation of liquid.

When a solid is present in a liquid or a non-volatile substance is present in a liquid, the vapor pressure of the pure liquid tends to decrease.

The presence of a non-volatile solute in a solution reduces the escaping tendency of the solvent molecules into the vapor phase. This happens because solute particles occupy the position of solvent molecules on the liquid surface.

We are given an aqueous solution of sodium chloride and pure water.

Hence, vapor pressure of the solution will be less than the pure water.