Question Video: Deducing What Should Be Done with Hanging Drops from a Buret When Running a Titrant Chemistry

What should be done with any hanging drops of titrant that remain after running in a titrant from a buret?

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Video Transcript

What should be done with any hanging drops of titrant that remain after running in a titrant from a buret? (A) The drops should be left hanging from the buret and the conical flask should be carefully moved away. (B) The drops should be absorbed using a small piece of paper towel. (C) The drops should be added to the conical flask by gently flicking the nozzle of the buret. (D) The drops should be collected in a second conical flask. Or (E) the drops should be collected and reintroduced to the top of the buret.

In order to answer this question, we need to understand how a buret is used to run a titrant.

A buret is used to run a titrant in a procedure called a titration. A titration is a quantitative analytical method used to determine the concentration of an analyte using a known concentration of a second solution. The buret is clamped upright over a conical flask. It contains the solution of known concentration. This solution is called the titrant. Into the analyte below, the buret releases a volume of titrant until the reaction is complete and the data can be used to find the concentration of the analyte.

In order for this quantitative method to be valid, the volume of known solution reacted must be precisely and accurately measured using the gradations on the buret. If drops are left hanging on the end of the buret, the volume reading is compromised. With this in mind, let’s have a look at our answer choices.

Answer choice (A) suggests that the conical flask be moved away and the drops left on the buret. These remaining drops would be included in the volume reading on the buret as it is no longer contained in the glassware but would not be reacted in the conical flask and thus would alter the results. Similarly, absorbing the drops using a paper towel as suggested by answer choice (B) would alter the results.

Answer choice (D) suggests the drops be collected by a second flask, which would still alter the results by removing the drops but not reacting them with the analyte. Answer choice (E) suggests the drops be collected and reintroduced into the top of the buret. While this might not alter the results, it is an impractical method and this transfer would be difficult.

Answer choice (C) suggests the drops be added to the conical flask containing the analyte by gently flicking the nozzle of the buret. This would allow the hanging drops to fall into the analyte and for the volume reading to be accurate. This would make the volume reading of the buret valid and the quantitative analysis to be reliable.

Therefore, the correct answer is (C). After running a titrant from a buret, any hanging drops that remain should be added to the conical flask by gently flicking the nozzle of the buret.

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