vapor pressure lowering

Vapor pressure lowering occurs when a non-volatile substance (like salt or sugar) dissolves in a liquid, reducing the tendency of the liquid molecules to escape into the air as vapor. This happens because the dissolved particles occupy space at the liquid’s surface, hindering some molecules from escaping. As a result, the pressure exerted by the vapor above the liquid decreases. The more solute dissolved, the greater the effect. This principle explains why adding salt to water raises its boiling point and is used in processes like preserving food and controlling boiling temperatures.