Forráspontemelkedés

Forráspontemelkedés, also known as boiling point elevation, is a colligative property of solutions. This means that the effect depends on the concentration of solute particles in a solvent, rather than the identity of the solute itself. When a non-volatile solute is dissolved in a solvent, the boiling point of the solution is higher than that of the pure solvent. This occurs because the solute particles interfere with the solvent molecules' ability to escape into the gas phase, thus requiring a higher temperature to achieve a vapor pressure equal to the surrounding atmospheric pressure.

The magnitude of the boiling point elevation is directly proportional to the molal concentration of the solute. The relationship can be expressed by the formula ΔTb = Kb * m * i, where ΔTb is the boiling point elevation, Kb is the ebullioscopic constant of the solvent, m is the molality of the solution, and i is the van't Hoff factor, which accounts for the number of particles a solute dissociates into in solution. For non-electrolytes, i is typically 1. For electrolytes, i is greater than 1 and depends on the degree of dissociation.

Forráspontemelkedés has several practical applications. It is used in the food industry to determine the concentration of solutes in liquids, such as sugar in fruit juices. It also plays a role in antifreeze formulations for car radiators, where the addition of ethylene glycol to water raises the boiling point, preventing the coolant from boiling over in hot conditions. Furthermore, it is a fundamental concept in understanding the behavior of solutions in various chemical and industrial processes.