Final answer:
The statement is "false". In an emulsion, the hydrophobic part of an emulsifier associates with the oil phase, not the water phase, while the hydrophilic head associates with the water phase.
Step-by-step explanation:
The statement that the hydrophobic part of an emulsifier associates with the water phase of an emulsion is false. An emulsifier is a molecule that contains two distinct parts: a hydrophobic tail that has little affinity for water and a hydrophilic head that is attracted to water.
When an emulsifier is added to an emulsion, the hydrophobic tail associates with the hydrophobic phase (for example, oil), while the hydrophilic head faces towards the water phase. This structure is crucial for stabilizing emulsions by preventing the coalescence of the hydrophobic liquid droplets.
A classic example of an emulsifier in action is soap, which can stabilize an emulsion of kerosene in water. Additionally, in biological systems, phospholipids form bilayers with the hydrophobic tails inward and the hydrophilic heads outward, interacting with the aqueous environment.