Home › NEET & JEE Chemistry MCQs › Aldehydes Ketones and Carboxylic Acids
NEET & JEE · Chemistry · Class 12

Aldehydes Ketones and Carboxylic Acids — NEET & JEE Chemistry MCQs

30 questions written by hand against the NCERT chapter. Every wrong option is explained, not just the right one.

30questions
10/14/6easy / medium / hard
₹0no login
Take the Aldehydes Ketones and Carboxylic Acids test →
Free · your all-India rank after you finish

Sample questions from this chapter

What is the geometry around a carbonyl carbon?
  1. Trigonal planar with approximately 120° bond angles ✓
  2. Tetrahedral with approximately 109.5° angles
  3. Linear with 180° angles
  4. Trigonal pyramidal with a carbon lone pair
Answer: A. The carbonyl carbon is sp2 hybridised and trigonal planar; nucleophilic addition converts it to a tetrahedral alkoxide. Using the product geometry for the reactant is the main trap.
Why not B: Carbonyl carbon is sp2 before nucleophilic addition, not sp3.
Why not C: sp hybridisation would be required for linear geometry.
Why not D: Carbonyl carbon has no lone pair and lies in the plane of its three sigma bonds.
What product forms when ethanal reacts with HCN?
  1. Ethanoic acid
  2. Ethanol
  3. 2-Hydroxypropanenitrile ✓
  4. Propanone
Answer: C. CN− attacks carbonyl carbon and protonation gives CH3CH(OH)CN, a cyanohydrin with one extra carbon. Ethanoic acid is the oxidation trap.
Why not A: This would be oxidation of the aldehyde.
Why not B: This would be reduction of the carbonyl.
Why not D: HCN adds C and N rather than converting the aldehyde into a ketone.
An unknown C8H8O compound gives 2,4-DNP and iodoform tests but not Tollens test. Vigorous oxidation gives benzoic acid. What is it?
  1. Acetophenone ✓
  2. Phenylacetaldehyde
  3. Methyl benzoate
  4. Ethylbenzene
Answer: A. C6H5COCH3 is an aromatic methyl ketone: DNP-positive, iodoform-positive, Tollens-negative, and side-chain oxidation yields benzoic acid. Phenylacetaldehyde is the aldehyde trap.
Why not B: An aldehyde should reduce Tollens reagent and its structure is not a methyl ketone.
Why not C: An ester does not give the ordinary 2,4-DNP carbonyl test or iodoform response.
Why not D: A hydrocarbon lacks the carbonyl detected by 2,4-DNP.

These are 3 of the 30 questions in the test. Take the full chapter test →

Read the chapter first

Every NCERT question in this chapter is solved, free: NCERT solutions — Aldehydes Ketones and Carboxylic Acids →

Other NEET Chemistry chapters

Some Basic Concepts of ChemistryStructure of AtomClassification of Elements and Periodicity in PropertiesChemical Bonding and Molecular StructureThermodynamicsEquilibrium

All 19 chapters →

Questions

How many NEET and JEE questions are there on Aldehydes Ketones and Carboxylic Acids?

This chapter test has 30 questions — 10 easy, 14 medium and 6 hard — all written against the NCERT Class 12 chapter.

Is this NEET and JEE Chemistry chapter test free?

Yes. Every chapter test is free with no login, and you get your all-India rank on every one. Nothing on the site is on sale right now.

Do the questions explain the wrong options?

Yes — every distractor carries its own explanation naming the specific misconception that makes a student pick it. That is the part most question banks skip, and it is the part that changes your next attempt.