Exams › JEE Main › Chemistry

Which one of the following reactions will not form acetaldehyde? (1) CH3CH2OH —Cu, 573 K→ (2) CH3CN —(i) DIBAL-H (ii) H2O→ (3) CH2=CH2 + O2 —Pd(II)/Cu(II)→ H2O (4) CH3CH2OH —CrO3/H2SO4→

1. (1)
2. (2)
3. (3)
4. (4)

Correct answer: (4)

Solution

Reactions (1) Cu/573K dehydrogenation, (2) CH3CN + DIBAL-H then H2O, and (3) Wacker oxidation of ethene all give acetaldehyde. But (4) ethanol with CrO3/H2SO4 (a strong oxidant) oxidizes all the way to acetic acid, so it does NOT form acetaldehyde.

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 →