Which of the following functional groups is commonly found in compounds that act as emulsifiers?

• A. Aldehyde group
• B. Amphiphilic group (containing both hydrophilic and hydrophobic regions, such as in phospholipids)
• C. Ester group
• D. Carboxyl group only

Answer: (B)

Verified step by step guidance

1. Understand what an emulsifier is: an emulsifier is a molecule that helps mix two immiscible liquids, like oil and water, by stabilizing the mixture.
2. Recognize that emulsifiers must have both hydrophilic (water-attracting) and hydrophobic (water-repelling) parts to interact with both phases effectively.
3. Identify the functional groups listed: aldehyde, ester, carboxyl, and the amphiphilic group (which contains both hydrophilic and hydrophobic regions).
4. Analyze each group’s properties: aldehyde, ester, and carboxyl groups are generally either hydrophilic or hydrophobic but do not inherently contain both regions in one molecule.
5. Conclude that the amphiphilic group, which has both hydrophilic and hydrophobic parts (like phospholipids), is the functional group commonly found in emulsifiers because it can interact with both oil and water phases.