ISC 2024 Chemistry Question Paper for Class 12

About this paper

This is ISC Class 12 Chemistry Paper 1 (Theory), code 862A, from the 2024 board examination. It carries 70 marks over three hours, with fifteen minutes to read the paper, and all 21 questions are compulsory. Section A is one 14-mark question: four fill-in-the-blank items, seven multiple-choice items of which two are assertion–reason, and a short passage on osmosis about eggs placed in water and in sucrose solution. Section B has ten two-mark questions, Section C seven three-mark questions and Section D three five-mark questions, with an internal choice in one question of each of those sections. Later questions include a protein osmotic-pressure calculation, a barium chloride boiling-point problem and the complex CoCl3·4NH3. Constants are printed for the numerical work. This copy has the questions only.

Exam

ISC Class 12

Subject

Chemistry

Year

2024

Paper code

862A

Maximum marks

70

Time allowed

3 hours + 15 min reading

Questions

21

Pages

10

Answers included

No, questions only

Paper pattern

• Section A

  14 marks

  Question 1 with 14 one-mark sub-parts: four fill-in-the-blanks, seven multiple-choice items (two assertion–reason) and three questions on an osmosis passage

• Section B

  20 marks

  Questions 2–11, two marks each; internal choice in one question

• Section C

  21 marks

  Questions 12–18, three marks each; internal choice in one question

• Section D

  15 marks

  Questions 19–21, five marks each; internal choice in one question

Topics covered

• Chemical kinetics
• Solutions and colligative properties
• Electrochemistry
• Coordination compounds
• d- and f-block elements
• Haloalkanes and haloarenes
• Alcohols, phenols and ethers
• Aldehydes and ketones
• Amines
• Biomolecules

Questions from this paper

1. Write a chemical test to distinguish between ethanol and phenol.
2. Why are zinc, cadmium and mercury regarded as d-block elements but not as transition elements?
3. If 200 cm³ of an aqueous protein solution contains 1.26 g of protein and the osmotic pressure at 300 K is 2.57 × 10−3 atm, calculate the molar mass of the protein. (R = 0.0821 L atm K−1 mol−1.)
4. An organic compound C2H4O gives a red precipitate with Fehling's solution and undergoes aldol condensation with dilute NaOH. Identify the compound and write its IUPAC name.
5. An aqueous solution containing 12.50 g of barium chloride in 1000 g of water boils at 373.0834 K. Calculate the degree of dissociation of barium chloride. (Kb for water = 0.52 K kg mol−1; molecular mass of BaCl2 = 208.34 g mol−1.)
6. A coordination compound CoCl3·4NH3 precipitates silver ions as AgCl and its molar conductance corresponds to two ions. Deduce its structural formula and IUPAC name.