Worksheets › Class 12 › Aldehydes, Ketones and Carboxylic Acids
Class 12 Aldehydes, Ketones and Carboxylic Acids worksheet
CBSE Chemistry. Tollens', Fehling's and iodoform tests, aldol and Cannizzaro, named reductions, acid strength, esters. Every sheet has 20 questions in three sections and an answer key, and the numbers change every time.
Sample questions
Real questions from this chapter, as the app sets them. Tap Answer to see the answer and working.
Section A · multiple choice
- 1.
The carbonyl carbon is:
- sp hybridised
- tetrahedral
- sp³ hybridised
- sp² hybridised and trigonal planar
Answer
(d) sp² hybridised and trigonal planar
- 2.
The IUPAC name of CH₃COCH₃ (acetone) is:
- propanone
- butanal
- diphenylmethanone
- pentan-3-one
Answer
(a) propanone
- 3.
Which of these gives a positive result with Tollens' test (silver mirror)?
- pentan-3-one
- diphenylmethanone
- methanal
- propanone
Answer
(c) methanal
methanal: is an aldehyde
Section B · short answer
- 4.
Why do aldehydes and ketones have lower boiling points than alcohols of similar mass?
Answer
They have polar C=O groups but cannot form intermolecular hydrogen bonds with each other, unlike alcohols.
- 5.
Name the ester formed from butanoic acid and methanol, and give its molecular formula and molar mass. (C = 12, H = 1, O = 16)
Answer
methyl butanoate; C₅H₁₀O₂; 102 g/mol
acid + alcohol → ester + water
Section C · long answer
- 6.
Describe the nucleophilic addition reactions of aldehydes and ketones, with the mechanism.
Answer
A nucleophile attacks the positive carbonyl carbon from above or below the plane, giving a tetrahedral alkoxide intermediate, which takes up a proton. Examples: HCN gives cyanohydrins; NaHSO₃ gives bisulphite addition products; Grignard reagents then water give alcohols; alcohols give hemiacetals and acetals.
Fresh sheets for your child
In the app, every Aldehydes, Ketones and Carboxylic Acids sheet is new: the app remembers the questions your child has already had and leaves them out. Print the sheet as a PDF, or use notebook mode and write the answers in a notebook.
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