NEET Aldehydes Ketones and Carboxylic Acids — Set 18

Question 1

Which compound forms a six-carbon tertiary alcohol when treated with $ \ce{CH3CH2CH2MgBr} $?

Accepted Answer

Propanone ($ \ce{CH3COCH3} $) reacts with $ \ce{CH3CH2CH2MgBr} $, adding a propyl group, forming 2-methylpentan-2-ol ($ \ce{CH3C(OH)(CH2CH2CH3)CH3} $), a six-carbon tertiary alcohol.

Question 2

Which compound shows a positive iodoform test and forms a tertiary alcohol with $ \ce{CH3MgBr} $?

Accepted Answer

Acetone ($ \ce{CH3COCH3} $) gives a positive iodoform test ($ \ce{CH3C=O} $) and reacts with $ \ce{CH3MgBr} $ to form 2-methylpropan-2-ol ($ \ce{(CH3)3COH} $), a tertiary alcohol.

Question 3

Which test gives a yellow precipitate with both acetaldehyde and acetone?

Accepted Answer

The iodoform test ($ \ce{I2, NaOH} $) is positive for compounds with $ \ce{CH3C=O} $, like acetaldehyde ($ \ce{CH3CHO} $) and acetone ($ \ce{CH3COCH3} $), forming $ \ce{CHI3} $.

NEET Chemistry: Aldehydes Ketones and Carboxylic Acids — Practice Set 18

Q1. Which compound forms a six-carbon tertiary alcohol when treated with \( \ce{CH3CH2CH2MgBr} \)?

Q2. Which compound shows a positive iodoform test and forms a tertiary alcohol with \( \ce{CH3MgBr} \)?

Q3. Which test gives a yellow precipitate with both acetaldehyde and acetone?

Q4. Which test produces a pink color with butanal but not with butan-2-one?

Q5. Which of the following does not undergo Cannizzaro reaction?

Q6. Which compound is formed when propanone reacts with 2,4-dinitrophenylhydrazine?

Q7. Which compound does not undergo the iodoform test?

Q8. Which reaction converts ethanal to ethanol?

Q9. Which carboxylic acid has the highest solubility in water among the following?

Q10. Which compound gives a positive Schiff’s test but not Fehling’s test?