In which scenario can the concept of colligative properties be applied?

Colligative properties are characteristics of solutions that depend on the number of solute particles in a given amount of solvent rather than the identity of the solute itself. The scenario that demonstrates this principle is when lowering the freezing point of water for preservation. When a solute is added to water, it disrupts the ability of water molecules to form a solid crystalline structure, effectively lowering the freezing point. This is a direct application of colligative properties, as the extent of freezing point depression is influenced by the concentration of solute particles.

In this process, common examples include the addition of salt or antifreeze to water, where the resulting solution has a lower freezing point than pure water. This phenomenon is critical for practical applications like food preservation or preventing the freezing of water in cold environments.

The other scenarios do not relate to colligative properties. Molarity is a concentration measure but does not directly invoke colligative effects. The color intensity of a solution is influenced by the nature and concentration of the solute but does not pertain to colligative properties. Measuring pH deals with the acidity or basicity of a solution, which is not a colligative property but rather a property of the chemical species present.