Aldehydes, Ketones and Carboxylic Acids MCQs

The various classes of organic compounds containing carbonyl groups are aldehydes, ketones, carboxylic acids and their derivatives. The carbonyl carbon of the simplest aldehyde, formaldehyde is bonded to two hydrogen atoms. All other aldehydes contain the carbonyl carbon bonded to a hydrogen atom and to an alkyl group. The carbonyl carbon of a ketone is bonded to two alkyl groups. Carboxylic acids are obtained by the oxidation of primary alcohols or aldehydes. They are also obtained by the hydrolysis of nitriles, acid chlorides, esters, anhydrides and amides.

1. A mixture of benzaldehyde and formaldehyde on heating with aqueous NaOH solution gives

1. benzyl alcohol + sodium formate
2. sodium benzoate + methanol
3. benzyl alcohol + methanol
4. sodium benzoate + sodium formate

Answer: (a)

2. Which of the following has the most acidic hydrogen?

1. hexane-2,4-dione
2. hexane-2,3-dione
3. hexane-2,5-dione
4. hexane-3-one

Answer: (a)

3. A new C-C bond formation is possible in

1. cannizzaro reaction
2. friedel crafts reaction
3. clemmensen reduction
4. reimer tiemann reaction

Answer: (b,d)

4. Under Wolff-Kishner reduction conditions, the conversions which may be brought about are

1. cyclohexanone into cyclohexane
2. benzaldehyde into benzyl alcohol
3. cyclohexanone into cyclohexanol
4. benzophenone into diphenylmethane

Answer: (a,d)

5. The formation of cyanohydrin from a ketone is an example of

1. electrophilic addition
2. nucleophilic addition
3. nucleophilic substitution
4. electrophilic substitution

Answer: (b)

6. Benzoic acid reacts with conc.HNO₃ and conc.H₂SO₄ to give

1. o-nitrobenzoic acid
2. p-nitrobenzoic acid
3. m-nitrobenzoic acid
4. o,p-dinitrobenzoic acid

Answer: (c)

7. An inorganic compound producing an organic compound on heating is

1. ammonium cyanate
2. soda lime
3. sodamide
4. potassium cyanide

Answer: (a)

8. The reaction of ethyl formate with an excess of CH₃MgI followed by hydrolysis gives

1. ethanol
2. n-propyl alcohol
3. propanal
4. isopropyl alcohol

Answer: (d)

9. Formic acid and acetic acid are distinguished by reaction with

1. sodium ethoxide
2. sodium
3. HgCl₂
4. 2,4-dinitrophenylhydrazine

Answer: (c)

10. Heating a mixture of sodium benzoate and soda lime gives

1. calcium benzoate
2. benzene
3. sodium benzoate
4. methane

Answer: (b)

Further reading:

• NEET Chemistry Syllabus
• NEET Chemistry Important Topics
• NEET Chemistry MCQs
• How to Score 160 Plus in NEET Chemistry
• NEET Chemistry Weightage
• Chemistry Formulas for NEET