Predict the bond angles marked $x$ and $y$ in the hydroxyethanal diagram.
Hydroxyethanal is tested separately with 2,4-dinitrophenylhydrazine (2,4-DNPH) and with Tollens’ reagent. State the observation in each case.
When hydroxyethanal is oxidised to ethanedioic acid, $(\text{CO}_2\text{H})_2$, by excess acidified dichromate(VI) ions, $\text{Cr}_2\text{O}_7^{2-}$, state the role of the acidified $\text{Cr}_2\text{O}_7^{2-}$ in this reaction.
State and explain any other conditions needed for this reaction to work successfully.
Hydroxyethanal may be reduced to ethane-1,2-diol, $(\text{CH}_2\text{OH})_2$, as shown. Write an equation for the reduction of hydroxyethanal to $(\text{CH}_2\text{OH})_2$. Use $[\text{H}]$ to stand for one hydrogen atom from the reducing agent.
Identify a reagent for this reduction reaction.
$(\text{CH}_2\text{OH})_2$ is also produced when alkene A reacts with cold, dilute, acidified manganate(VII) ions. Name A.