(a(i))[1]
Explain what structural isomerism means.
(a(ii))[2]
State two different molecular features that can produce stereoisomerism.
(b)[1]
Give the structural formula of the organic compound formed when tartaric acid, $\text{HO}_2\text{CCH(OH)CH(OH)CO}_2\text{H}$, is treated with excess $\text{NaHCO}_3$.
(c)[1]
Does citric acid exhibit optical isomerism? Explain your answer.
(d(i))
Show, by calculation, that the empirical formula for $W$ is $\\text{C}_4\\text{H}_6\\text{O}_5$.
(d(ii))[3]
Given that the $M_r$ of $W$ is $134$, use this to work out the molecular formula of $W$.
(e(i))
Use these data to determine how many carboxylic acid groups are in one molecule of $W$.
(e(ii))[5]
Suggest the displayed formula of $W$.