Bay laurel oil contains a triester with three identical R groups. This triester reacts with potassium hydroxide to form propane-1,2,3-triol and a potassium carboxylate salt.
The triester in bay laurel oil has a relative molecular mass, Mr=638.0M_r = 638.0Mr=638.0. In this triester, the R group represents an alkyl group that can be written as CH3(CH2)n\text{CH}_3(\text{CH}_2)_nCH3(CH2)n. Deduce the value of nnn in CH3(CH2)n\text{CH}_3(\text{CH}_2)_nCH3(CH2)n. Show your working.
A 1.650 g1.650\text{ g}1.650 g sample of bay laurel oil is heated with 0.500 g0.500\text{ g}0.500 g of KOH\text{KOH}KOH (Mr=56.1M_r=56.1Mr=56.1) in aqueous ethanol until all of the triester is hydrolysed. The mixture is cooled. The remaining KOH\text{KOH}KOH is neutralised by exactly 17.00 cm317.00\text{ cm}^317.00 cm3 of 0.150 mol dm−3 HCl0.150\text{ mol\,dm}^{-3}\ \text{HCl}0.150 moldm−3 HCl. Calculate the percentage by mass of the triester (Mr=638.0M_r=638.0Mr=638.0) in the bay laurel oil. Show your working.
Suggest why aqueous ethanol is a suitable solvent when heating the bay laurel oil with KOH\text{KOH}KOH. Give a safety precaution used when heating the mixture and justify your choice.