Edexcel A-Level Chemistry A2 6 P11 Selecting Laboratory Apparatus Questions

This question is about copper and some of its compounds.

Brass is an alloy of copper and zinc.

A student determined the percentage of copper in a sample of brass.

Procedure
- weigh the sample of brass
- place the brass in a beaker and add concentrated nitric acid until all the brass dissolves
- transfer the solution and washings to a $250.0 \mathrm{~cm}^{3}$ volumetric flask
- make the solution up to the mark with distilled water and mix well
- pipette $25.0 \mathrm{~cm}^{3}$ of the solution into a conical flask
- neutralise the excess nitric acid in the solution
- add $10 \mathrm{~cm}^{3}$ of potassium iodide solution (an excess) to the conical flask
- titrate the iodine produced with $0.100 \mathrm{~mol} \mathrm{dm}^{-3}$ sodium thiosulfate solution using starch indicator
- repeat the titration until concordant titres are obtained.

Name the most suitable piece of apparatus to measure the $10 \mathrm{~cm}^{3}$ of potassium iodide solution.