Aldehydes and ketones are organic compounds that contain a special group called the carbonyl group (C=O). This group is made when a carbon atom is double-bonded with an oxygen atom.
In aldehydes, this group is found at the end of the carbon chain because it is attached to at least one hydrogen atom (R–CHO). In ketones, the carbonyl group is located in the middle of the chain, bonded with two carbon atoms (R–CO–R′).
Both aldehydes and ketones are commonly found in nature and have many uses in everyday life, such as in perfumes, flavors, and industrial products.
This PDF also includes MCQs, short questions, long questions, and solved exercises for better exam preparation.
📥 DOWNLOAD Class 12 Chemistry Unit 12 – Aldehydes and Ketones Notes
Skip to PDF contentGet complete Class 12 Chemistry Unit 12: Aldehydes and Ketones Notes (Punjab Board) in a well-organized PDF file. This PDF includes:
- Easy and clear theory notes
- Step-by-step explanations
- Important MCQs
- Short questions for exams
- Long questions with answers
👉 Download PDf: Click here to download Class 12 Chemistry Unit 12 Notes
❓ FAQ –Aldehydes and Ketones
Q1: What are aldehydes and ketones?
Aldehydes and ketones are organic compounds that contain the carbonyl group (C=O) as their main functional group.
Q2: What is the main difference between aldehydes and ketones?
In aldehydes, the carbonyl group is at the end of the chain (R–CHO), while in ketones it is in the middle of the chain (R–CO–R′).
Q3: What is the general formula of aldehydes and ketones?
Both aldehydes and ketones have the general formula CnH₂nO.
Q4: Where are aldehydes and ketones used in daily life?
They are used in perfumes, flavors, solvents, and many industrial chemical products.
Q5: Why are aldehydes and ketones important in chemistry?
They are important because they help in understanding carbonyl chemistry, reactions, and organic synthesis, and are commonly asked in exams.
📝 MCQs – Aldehydes and Ketones
Q1: The functional group present in aldehydes and ketones is:
(a) –OH
(b) –COOH
(c) –CHO
(d) C=O ✅
Q2: Aldehydes always have carbonyl group at:
(a) Middle of chain
(b) End of chain ✅
(c) Side chain only
(d) Ring structure
Q3: General formula of aldehydes and ketones is:
(a) CnH₂n+2
(b) CnH₂nO ✅
(c) CnH₂n-2
(d) CnH₂n+1O
Q4: Ketones contain carbonyl group between:
(a) Hydrogen atoms
(b) Two carbon atoms ✅
(c) Oxygen atoms
(d) Nitrogen atoms
Q5: Which of the following is an aldehyde?
(a) Propanone
(b) Ethanol
(c) Ethanal ✅
(d) Propanol