ISC 2023 Chemistry Question Paper for Class 12

About this paper

This is ISC Class 12 Chemistry Paper 1 (Theory), code 862A, set by CISCE for the 2023 board examination. It carries 70 marks and runs for three hours, with fifteen minutes extra for reading only. All 21 questions are compulsory, with an internal choice in one question each in Sections B, C and D. Section A is a single question of fill-in-the-blanks, multiple choice, matching and two assertion-reason items. The later sections move from two-mark reasons and cell calculations to three-mark name reactions and five-mark questions on carbonyl compounds, coordination compounds and conductance. Values of the gas constant, the Faraday and Avogadro's number are printed for the numerical work, and balanced equations are required wherever possible. This copy has the questions only.

Exam

ISC Class 12

Subject

Chemistry

Year

2023

Paper code

862A

Maximum marks

70

Time allowed

3 hours + 15 min reading

Questions

21

Pages

9

Answers included

No, questions only

Paper pattern

• Section A

  14 marks

  Question 1: four fill-in-the-blanks, four multiple-choice items, four matching items and two assertion-reason items, one mark each

• Section B

  20 marks

  Questions 2–11, two marks each, with an internal choice in Question 8

• Section C

  21 marks

  Questions 12–18, three marks each, with an internal choice in Question 17

• Section D

  15 marks

  Questions 19–21, five marks each, with an internal choice in Question 21

Topics covered

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

Questions from this paper

1. Why are Cu²⁺ salts paramagnetic while Cu⁺ salts are diamagnetic, and why are Mn²⁺ compounds more stable than Fe²⁺ compounds?
2. The osmotic pressure of blood at 37°C is 8.21 atm. How many grams of glucose should be used per litre of aqueous solution for an intravenous injection that is isotonic with blood? The molecular weight of glucose is 180 g/mol.
3. Twenty percent of a first-order reaction is completed in five minutes. How long will it take for 60 percent of the reaction to be completed, and what is the half-life?
4. Write balanced chemical equations for Sandmeyer's reaction, the Wurtz reaction and the Finkelstein reaction.
5. Give an example each of a reducing sugar and a non-reducing sugar, explain denaturation of proteins, and give an example each of a water-soluble and a fat-soluble vitamin.
6. Name the type of isomerism shown by [Co(NH₃)₅(ONO)]Cl₂ and [Co(NH₃)₅(NO₂)]Cl₂.