Adding a nonvolatile solute to a solution decreases the vapor pressure of the solution. True or False

True.

Explanation:

Adding a non - volatile solute to solvent, decreases the tendency for water molecules to evaporate into gas phase i. e these non - volatile solute particles obstruct or reduce the rate of evaporation. Few water molecules in the vapour.

Therefore, Adding a nonvolatile solute to a solution decreases the vapor pressure of the solution while

Vapor pressure is a measurement of the likelihood of the molecules of a pure solvent to change from the liquid to the vapor phase.

Using Raoult's Law:

Psol = Xsolv * P°solv

where:

Psol = the vapor pressure of the solvent above the solution,

Xsolv = the mole fraction of the solvent in the solution, and

P°solv = the vapor pressure of the pure solvent.