Basic Wastewater Operator Practice Exam

What is the correct procedure for mixing acid and water?

1. Add acid to water slowly while stirring to dissipate heat

2. Water to acid

3. Do not mix

4. Pour both into a beaker at the same time

The correct answer is: Add acid to water slowly while stirring to dissipate heat

The correct procedure is to add acid to water slowly while stirring to dissipate heat. This method is crucial for safety because mixing water and acid can generate significant heat, which can lead to splattering or boiling if water is added to acid. By adding acid to water, the heat generated is more effectively dispersed throughout the larger volume of water, minimizing the risk of violent reactions and potential injuries. The other options don't provide a safe method for mixing these substances. Adding water to acid could result in a hazardous reaction, as water is a smaller volume and can cause the acid to heat up very quickly, potentially splashing. Stating not to mix altogether ignores instances where mixing is necessary, albeit safely. Pouring both into a beaker at the same time can also result in dangerous reactions, as it doesn't control the heat generation effectively. Thus, the recommended procedure ensures both safety and efficiency.