National League for Nursing (NLN PAX) Practice Exam

The correct answer is that the presence of salt increases the boiling point of water. This phenomenon is known as boiling point elevation, a colligative property of solutions. When salt (sodium chloride) is dissolved in water, it dissociates into its constituent ions (sodium and chloride ions). This process disrupts the ability of water molecules to escape into the vapor phase, thus requiring a higher temperature to achieve boiling.

In pure water, the boiling point is determined by the atmospheric pressure and the energy of the water molecules at that temperature. When solute particles, such as salt ions, are added, they effectively increase the number of particles present in the solution, which influences the overall vapor pressure. As a result, more energy (in the form of heat) must be supplied to reach the boiling point, leading to an elevation in the boiling point compared to pure water.

This principle has practical applications in cooking and food preparation, where adding salt to boiling water not only enhances flavor but also raises the temperature, allowing food to cook more thoroughly in less time.