CBSE 2018 Chemistry Question Paper for Class 12

About this paper

This is the CBSE Class 12 Chemistry (Theory) question paper code 56/2, Series SGN, Set 2, from the 2018 board examination, printed in both Hindi and English. It carries 70 marks over three hours and has 26 compulsory questions: five one-mark, five two-mark, twelve three-mark, one four-mark value-based question and three five-mark long answers. The value-based question is about a shopper who refuses polythene bags, leading to questions on low- and high-density polythene and biodegradable polymers. Internal choices are given in one two-mark question, one three-mark question and all three long answers, which cover electrochemistry, amines and the p-block. Log tables may be used, but calculators are not allowed. This copy has the questions only, without answers.

Exam

CBSE Class 12

Subject

Chemistry

Year

2018

Paper code

56/2

Maximum marks

70

Time allowed

3 hours + 15 min reading

Questions

26

Pages

15

Answers included

No, questions only

Paper pattern

• Questions 1–5

  5 marks

  Very short answer questions, one mark each

• Questions 6–10

  10 marks

  Short answer questions, two marks each; internal choice in one

• Questions 11–22

  36 marks

  Short answer questions, three marks each; internal choice in one

• Question 23

  4 marks

  Value-based question

• Questions 24–26

  15 marks

  Long answer questions, five marks each, each with an internal choice

Topics covered

• Solid state
• Solutions and colligative properties
• Electrochemistry
• Chemical kinetics
• Surface chemistry and colloids
• Isolation of elements
• p-Block elements
• d- and f-Block elements
• Coordination compounds
• Haloalkanes, alcohols and ethers
• Aldehydes, ketones, carboxylic acids and amines
• Biomolecules, polymers and chemistry in everyday life

Questions from this paper

1. Write the coordination number and oxidation state of platinum in the complex [Pt(en)₂Cl₂].
2. For the reaction 2N₂O₅(g) → 4NO₂(g) + O₂(g), the rate of formation of NO₂(g) is 2.8 × 10⁻³ M s⁻¹. Calculate the rate of disappearance of N₂O₅(g).
3. An element X (at. mass = 40 g mol⁻¹) with an f.c.c. structure has a unit cell edge length of 400 pm. Calculate the density of X and the number of unit cells in 4 g of X. (Nₐ = 6.022 × 10²³ mol⁻¹)
4. A first order reaction is 50% completed in 40 minutes at 300 K and in 20 minutes at 320 K. Calculate the activation energy of the reaction.
5. Write the chemical reactions involved in the extraction of gold. Explain the role of dilute NaCN and Zn in this process.
6. Why is bithional added to soap?