In shampoo chemistry, what does the hydrophilic head of the molecule do?

• A. Attracts water and repels oil and grease
• B. Attracts water and oil
• C. Repels water and attracts oil
• D. Attracts oil and grease

Answer: (A)

The hydrophilic head is the water-loving part of a surfactant. Its job is to attract and interact with water, helping the molecule stay in the aqueous phase. In shampoo, the nonpolar tails are attracted to oils and dirt, while the heads face the water. This arrangement lets dirt and oil be trapped inside micelles, with the outer surface of the micelle being water-friendly, so the entire complex can be rinsed away with water. Because the head prefers water, it doesn’t bind to oil; it effectively helps separate oil from hair and grease, making cleansing and rinsing possible.