Which of the following substances commonly found in shampoos is highly flammable and has an astringent quality that causes it to evaporate quickly?

• A. Sodium lauryl sulfate
• B. Glycerin
• C. Ethanol
• D. Water

Answer: (C)

Verified step by step guidance

1. Identify the properties described in the question: the substance is highly flammable, has an astringent quality, and evaporates quickly.
2. Recall that sodium lauryl sulfate is a surfactant commonly used for cleaning but is not highly flammable and does not evaporate quickly.
3. Consider glycerin, which is a viscous, non-flammable humectant that does not evaporate quickly and lacks astringent properties.
4. Water is non-flammable and evaporates relatively slowly compared to volatile organic compounds.
5. Ethanol is a volatile organic compound that is highly flammable, has an astringent (drying) effect, and evaporates quickly, matching all the properties described.