When cleaning a buret, you should begin by coating the inside with which of the following substances?

• A. the solution to be used in the titration
• B. distilled water
• C. acetone
• D. dilute hydrochloric acid

Answer: (A)

Verified step by step guidance

1. Understand the purpose of cleaning a buret before a titration: it is to ensure that the inside surface is free of contaminants and that the solution used in the titration will not be diluted or contaminated by residual substances.
2. Recognize that rinsing the buret with distilled water removes impurities but leaves water inside, which can dilute the titrant solution and affect accuracy.
3. Consider that rinsing with acetone or dilute hydrochloric acid could leave residues or react with the titrant, potentially altering the concentration or causing contamination.
4. Learn that the best practice is to rinse the buret with the solution that will be used in the titration itself, so the inside surface is coated with the exact solution, preventing dilution or contamination.
5. Therefore, the correct substance to coat the inside of the buret before filling it for a titration is the solution to be used in the titration.