A student removes a chemical sample from a reagent bottle

Subject : Chemistry

Question: A student removes a chemical sample from a reagent bottle to be used in an experiment. What should he do with any excess chemicals remaining from this sample after the experiment is complete?

Select one:

A) Check and see if anyone else can use the chemical. If not, discard in the proper waste container.

B) Conduct a second trial of the experiment with the excess chemical.

C) Discard the chemical down the sink under running water.

D) Clean a spatula thoroughly, then use it to add the chemical back into the reagent bottle.

Expert Verified Solution:

The correct answer is:

A) Check and see if anyone else can use the chemical. If not, discard in the proper waste container.

Explanation:

Option A is correct because leftover chemicals should never be returned to the original reagent bottle due to the risk of contamination, which can compromise future experiments and safety. Instead, the student should first check if any other lab members can use the excess chemical. If no one else needs it, the student should dispose of the chemical in the designated waste container according to the lab’s safety and disposal guidelines.

Option B is incorrect because conducting a second trial should not be done without proper authorization or a scientific need, and it doesn’t address the proper disposal or reuse of excess chemicals.

Option C is incorrect because disposing of chemicals down the sink is dangerous unless specifically stated as safe by the lab’s safety protocol. Some chemicals can react with water, cause environmental harm, or corrode plumbing.

Option D is incorrect because returning excess chemicals to the reagent bottle poses a significant risk of contaminating the entire reagent supply, which can lead to inaccurate experimental results or dangerous reactions in future experiments.