Which diagram shows the expected arrangement of soap anions in an emulsion? A - HSC - SSCE Chemistry - Question 8 - 2021 - Paper 1

To determine the correct arrangement of soap anions in an emulsion, we need to understand how emulsifiers work. Soap molecules have a hydrophilic (water-attracting) head and a hydrophobic (water-repelling) tail. In an emulsion, soap anions will orient themselves with their hydrophilic heads in the water and their hydrophobic tails in the oil.

In the provided diagrams:

• Diagram A: Incorrect, as it does not show a suitable arrangement for soap anions.
• Diagram B: Incorrect, because soap anions are not properly aligned with respect to both phases.
• Diagram C: Incorrect, as it fails to depict the correct orientation of the soap molecules.
• Diagram D: Correct, as it appropriately shows the soap anions with their hydrophilic heads in the aqueous phase and their hydrophobic tails interacting with the oil phase.

Therefore, the best answer is Diagram D.