Q60 / 180 · COMEDK 2025 (10 May Shift 2) · Chemistry
Choose the incorrect statement.
- AAcetone undergoes Wolff Kishner reaction to yield Propane.
- Correct answerBThe increasing order of boiling points of 5 compounds having comparable molar masses is as follows: Methoxyethane \(<\) Propanone \(<\) Propanal \(<\) Propan-1-ol
- CThe order of reactivity towards Nucleophilic attack is Methanal > Ethanal > Benzaldehyde > Acetophenone
- DDuring nucleophilic addition of HCN to RCHO , the hybridisation changes from $\mathrm{sp}^2$ to $\mathrm{sp}^3$ and a tetrahedral intermediate is formed.
Solution
Statement (2) is incorrect because ketones have higher boiling points than isomeric aldehydes due to greater dipole-dipole interactions from two electron-donating alkyl groups. Propanone (b.p. $\approx 56°C$) boils higher than Propanal (b.p. $\approx 49°C$).
The correct increasing order of boiling points should be:
Methoxyethane $<$ Propanal $<$ Propanone $<$ Propan-1-ol
The given order in statement (2) places Propanone before Propanal, which is incorrect.
The correct increasing order of boiling points should be:
Methoxyethane $<$ Propanal $<$ Propanone $<$ Propan-1-ol
The given order in statement (2) places Propanone before Propanal, which is incorrect.
Hence, the correct answer is option: 'B'.