Canadian Society for Medical Laboratory Science (CSMLS) Practice Exam

How is acid diluted with water?

1. Mix in equal quantities

2. Add water to the acid or base

3. Add the acid or base to water

4. Work as quickly as possible

The correct answer is: Add the acid or base to water

Diluting acid with water must be done by adding the acid to the water rather than the other way around. This method is crucial because it minimizes the risk of a violent exothermic reaction that can occur if water is added directly to concentrated acid. When water is added to concentrated acid, the heat generated can lead to splattering or even boiling, creating dangerous situations. By adding the acid to the water, the acid disperses and is able to cool down as it mixes, resulting in a more controlled and safer dilution process. This practice is a fundamental safety principle in laboratory protocols involving strong acids and bases and aligns with standard safety guidelines across chemical handling. In summary, the correct answer underscores a critical safety measure in laboratory practices, ensuring a safer approach to diluting acids.