Question

for an experiment, the student needs 25 ml of 85% phosphoric acid. however, they inadvertently measured out 30 ml in the graduated cylinder. what should they do with the excess phosphoric acid? click on the single best answer.

• pour the excess into the \chemicals for disposal\ beaker.
• pour the excess into the sink by the lab bench.
• pour the excess back into the stock bottle labeled \85% phosphoric acid.\

Explanation:

In a laboratory setting, it's a safety and protocol rule that excess chemicals (especially acids like phosphoric acid) should not be poured back into the stock bottle (to avoid contamination) or down the sink (to prevent damage to plumbing or environmental harm). Instead, they should be placed in a designated “Chemicals for Disposal” beaker for proper disposal by lab safety procedures.

Answer:

A. Pour the excess into the “Chemicals for Disposal” beaker.