A student is investigating the boiling points of straight-chain aldehydes. The table below shows the boiling points of some aldehydes:
| Name of aldehyde | Number of carbon atoms | Boiling point (∘C\phantom{}^{\circ}\text{C}∘C) |
|---|---|---|
| Methanal | 1 | -19 |
| Ethanal | 2 | 20 |
| Propanal | 3 | 48 |
| Pentanal | 5 | 103 |
| Hexanal | 6 | 130 |
Estimate the boiling point of butanal (which contains 4 carbon atoms) by considering the trend in the data.
Draw the displayed formula of butanal, C3H7CHO\text{C}_3\text{H}_7\text{CHO}C3H7CHO.
Aldehydes react in a similar way because they contain the same functional group. Identify this functional group.
Primary alcohols are oxidised to aldehydes. Ethanol (C2H5OH\text{C}_2\text{H}_5\text{OH}C2H5OH) is oxidised to ethanal (CH3CHO\text{CH}_3\text{CHO}CH3CHO). State the formula of the alcohol that is oxidised to propanal (C2H5CHO\text{C}_2\text{H}_5\text{CHO}C2H5CHO).