Chapter 8

Decide on the appropriate methods and equipment for the following procedures: (a) Preparing one litre of ethanol at approximately \(70 \% \mathrm{v} / \mathrm{v}\) in water for use as a general-purpose reagent. (b) Adding \(25.00 \mathrm{~mL}\) of concentrated hydrochloric acid to water (100 mL). (c) Adding \(10 \mu \mathrm{L}\) of propanone to a volumetric flask \((100.00 \mathrm{~mL}\) ) to produce an aqueous solution calibration standard for chromatography. (d) Titrating an unknown solution of sodium hydroxide (approximate concentration \(0.1 \mathrm{M}\) ) with sulphuric acid \((0.5 \mathrm{M})\).

After reading this chapter, prepare a streetwise protocol explaining how to use a pipettor to deliver a specific volume, say \(500 \mu \mathrm{L}\) (e.g. using a Gilson Pipetman \(^{\oplus}\) or an alternative if your department does not use this type). Ask another student to evaluate your protocol and provide you with feedback - either by reading through your protocol or by trying it out with a pipettor as part of a class exercise (check with a member of staff before you attempt this in a laboratory).