Notes are being written
The board questions below are real and complete — they come from the CBSE papers themselves. The written notes for this topic are still being prepared.
Board questions on this topic
4 from the CBSE papers we hold — the exact wording the board used.
2026Assertion-Reason·1 mark·Q24
Assertion (A): Pure ethanoic acid is also known as glacial acetic acid. Reason (R): Pure ethanoic acid often freezes during winter due to its low melting point of 290 K.
- (a) Both Assertion
- (b) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
- (c) Both Assertion
- (d) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
- (e) Assertion
- (f) is true, but Reason (R) is false.
- (g) Assertion
- (h) is false, but Reason (R) is true.
2025Long answer·5 marks·Q34(b)
(i) A carbon compound X is a good solvent. On reaction with sodium, X forms two products Y and Z. Z is used to convert vegetable oil into vegetable ghee. Identify and name X, Y and Z. Also write the equation of reaction of X with sodium to justify your answer. (ii) Write chemical equation to show what happens when ethanol: (I) burns in oxygen/air. (II) is heated at 443 K in excess conc. H_2SO_4. (III) reacts with acidified potassium dichromate.
2024Long answer·5 marks·Q34(b)
(i) Write the name and structure of an organic compound 'X' having two carbon atoms in its molecule and its name is suffixed with '-ol'. (ii) What happens when 'X' is heated with excess concentrated sulphuric acid at 443 K? Write chemical equation stating the conditions for the reaction. Also state the role played by concentrated sulphuric acid in the reaction. (iii) Name and draw the electron dot structure of hydrocarbon produced in the above reaction.
2023Long answer·5 marks·Q34(a)
A saturated organic compound 'A' belongs to the homologous series of alcohols. On heating 'A' with concentrated sulphuric acid at 443 K, it forms an unsaturated compound 'B' with molecular mass 28 u. The compound 'B' on addition of one mole of hydrogen in the presence of Nickel, changes to a saturated hydrocarbon 'C'. (i) Identify A, B and C. (ii) Write the chemical equations showing the conversion of A into B. (iii) What happens when compound C undergoes combustion? (iv) State one industrial application of hydrogenation reaction. (v) Name the products formed when compound A reacts with sodium.