Exams › JEE Main › Chemistry

The increasing order of the following compounds towards HCN addition is: (i) o-methoxybenzaldehyde (ii) o-nitrobenzaldehyde (iii) m-methoxybenzaldehyde (iv) m-nitrobenzaldehyde

1. (iii) < (iv) < (ii) < (i)
2. (iii) < (iv) < (i) < (ii)
3. (iii) < (i) < (iv) < (ii)
4. (i) < (iii) < (iv) < (ii)

Correct answer: (i) < (iii) < (iv) < (ii)

Solution

The correct order reflects the influence of substituents on the reactivity of the carbonyl group towards HCN addition. Electron-donating groups like methoxy increase nucleophilicity, while electron-withdrawing groups like nitro decrease it, leading to the observed increasing order of reactivity.

Related JEE Main Chemistry questions

• What is the product formed when toluene (C6H5CH3) is treated with chromyl chloride (CrO2Cl2)?
• o-Xylene is first treated with HNO3 to give compound X, which on reaction with phenol in the presence of H2SO4 forms product Y. What is Y?
• What products are formed when a benzene ring containing a formyl group (–CHO) and a chloro substituent is treated with 50% KOH?
• Which of the following compounds contains a carboxyl group (–COOH)?
• Which of the following compounds is converted to the corresponding hydrocarbon on reduction with zinc and hydrochloric acid?
• Why do carboxylic acids not undergo the typical addition–elimination reactions shown by aldehydes and ketones?

⚔️ Practice JEE Main Chemistry free + battle 1v1 →