ISC 2018 Chemistry Question Paper for Class 12

About this paper

This is ISC Class 12 Chemistry Paper 1 (Theory), code 862A, from the 2018 board examination. It carries 70 marks over three hours, with an extra fifteen minutes for reading, and all 18 questions are compulsory. Question 1 is worth 20 marks and mixes fill-in-the-blank items, multiple choice, matching and short calculations. Questions 2 to 8 carry two marks, questions 9 to 15 carry three marks, and questions 16 to 18 carry five marks. Two questions in each of the two-mark and three-mark groups have an internal choice, and every five-mark question has one. The paper includes a crystal-defect diagram and questions on colloids, drugs and the bases in RNA and DNA. Constants for the numerical work are printed. This copy has the questions only.

Exam

ISC Class 12

Subject

Chemistry

Year

2018

Paper code

862A

Maximum marks

70

Time allowed

3 hours + 15 min reading

Questions

18

Pages

8

Answers included

No, questions only

Paper pattern

• Question 1

  20 marks

  Four compulsory parts: fill in the blanks, multiple choice, matching and short answers

• Questions 2–8

  14 marks

  Two marks each; internal choice in two questions

• Questions 9–15

  21 marks

  Three marks each; internal choice in two questions

• Questions 16–18

  15 marks

  Five marks each, each with an internal choice

Topics covered

• Chemical kinetics
• Solutions and colligative properties
• Electrochemistry
• Solid state and crystal defects
• Surface chemistry
• Coordination compounds
• d-block elements
• p-block elements
• Metallurgy of copper
• Alcohols, phenols and ethers
• Biomolecules
• Polymers

Questions from this paper

1. Write the rate law for A + B + C → D + E if the order is first, second and zero with respect to A, B and C. How many times does the rate increase if the concentrations of A, B and C are doubled?
2. Forty percent of a first-order reaction is completed in 50 minutes. How long will it take for 80% of the reaction to be completed?
3. How do antiseptics differ from disinfectants?
4. Name the purine bases and the pyrimidine bases present in RNA and DNA.
5. Name the sulphide ore of copper and describe how pure copper is extracted from this ore.
6. Why does the density of the transition elements increase from titanium to copper, and why is zinc not regarded as a transition element?