NEET Aldehydes Ketones and Carboxylic Acids — Set 7

Question 1

Which ketone has the lowest boiling point among those with five carbon atoms?

Accepted Answer

3-Methylbutan-2-one ($ \ce{CH3COCH(CH3)2} $), with branching, has weaker dipole-dipole interactions than pentan-3-one or pentan-2-one, resulting in the lowest boiling point.

Question 2

What is the IUPAC name of $ \ce{CH3CH2C(CH3)=CHCOOH} $?

Accepted Answer

The compound has a 5-carbon chain with a carboxylic acid (pentanoic acid) and a double bond between C-3 and C-4, with a methyl on C-3: 3-methylpent-3-enoic acid.

Question 3

Which compound gives a positive Tollens' test but not an iodoform test?

Accepted Answer

Methanal ($ \ce{HCHO} $) is an aldehyde (positive Tollens' test) but lacks a $ \ce{CH3C=O} $ group (negative iodoform test).

NEET Chemistry: Aldehydes Ketones and Carboxylic Acids — Practice Set 7

Q1. Which ketone has the lowest boiling point among those with five carbon atoms?

Q2. What is the IUPAC name of \( \ce{CH3CH2C(CH3)=CHCOOH} \)?

Q3. Which compound gives a positive Tollens' test but not an iodoform test?

Q4. Which aldehyde is produced when 3-methylbut-1-yne undergoes hydration with \( \ce{HgSO4/H2SO4} \)?

Q5. Which compound undergoes the Cannizzaro reaction?

Q6. Which compound produces a yellow precipitate with \( \ce{I2/NaOH} \) and has seven carbon atoms?

Q7. Arrange in increasing order of solubility in water: \( \ce{CH3CH2COOH} \), \( \ce{CH3CH2CH2CH2COOH} \), \( \ce{CH3COOH} \).

Q8. What is the product when benzaldehyde reacts with \( \ce{C6H5MgBr} \) followed by hydrolysis?

Q9. Which of the following is a derivative of a ketone formed with semicarbazide?

Q10. Which compound gives a positive iodoform test but not a Tollens' test?