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previous-year-question-paper-2023-set-1

QUESTION PAPER

2023 BOARD EXAM

CBSE CLASS 12-PCM CHEMISTRY Board Paper 2023 — Set 1

2023

CHEMISTRY

CLASS 12-PCM

CBSE EXAMINATION PAPER-2023 CHEMISTRY

CBSE EXAMINATION PAPER-2023

CHEMISTRY

(Solved)

Time allowed : 3 hours

Maximum Marks : 10

General Instructions :

Read the following instructions carefully and follow them :

  1. This question paper contains 11 questions. All questions are compulsory.
  2. This question paper is divided into 3 sections.
  3. Section A – questions number 1 to 2 are case based questions
  4. Section B – questions number 3 to 10 are multiple choice questions
  5. Section C – questions number 11 to 11 are very short answer
  6. There is no overall choice given in the question paper. However, an internal choice has been provided in few questions.
  7. Use of calculator is NOT allowed.

Section A

Question 1. The rate of reaction is concerned with decrease in concentration of reactants or increase in the concentration of products per unit time. It can be expressed as instantaneous rate at a particular instant of time and average rate over a large interval of time. Mathematical representation of rate of reaction is given by rate law. Rate constant and order of a reaction can be determined from rate law or its integrated rate equation.
Question 2.

The rate of reaction is concerned with decrease in concentration of reactants or increase in the concentration of products per unit time. It can be expressed as instantaneous rate at a particular instant of time and average rate over a large interval of time. Mathematical representation of rate of reaction is given by rate law. Rate constant and order of a reaction can be determined from rate law or its integrated rate equation.

Section B

Question 3.

The colligative property used for the determination of molar mass of polymers and proteins is :

[1 Marks]
  • (A) Elevation is boiling point
  • (B) Depression in freezing point
  • (C) Relative lowering in vapour pressure
  • (D) Osmotic pressure
Question 4.

Low concentration of oxygen in the blood and tissues of people living at high altitude is due to :

[1 Marks]
  • (A) low atmospheric pressure
  • (B) both low temperature and high atmospheric pressure
  • (C) low temperature
  • (D) high atmospheric pressure
Question 5.

The correct cell to represent the following reaction is : Zn + 2Ag⁺ → Zn²⁺ + 2Ag

[1 Marks]
  • (A) Ag⁺ | Ag || Zn²⁺ | Zn
  • (B) Ag | Ag⁺ || Zn | Zn²⁺
  • (C) 2Ag | Ag⁺ || Zn | Zn²⁺
  • (D) Zn | Zn²⁺ || Ag⁺ | Ag
Question 6.

The most common and stable oxidation state of a Lanthanoid is :

[1 Marks]
  • (A) + 4
  • (B) + 6
  • (C) + 3
  • (D) + 2
Question 7.

The compounds [Co(SO₄)(NH₃)₅]Br and [Co(Br)(NH₃)₅]SO₄ represent :

[1 Marks]
  • (A) ionisation isomerism
  • (B) linkage isomerism
  • (C) coordination isomerism
  • (D) optical isomerism
Question 8.

The synthesis of alkyl fluoride is best obtained from :

[1 Marks]
  • (A) Sandmeyer reaction
  • (B) Finkelstein reaction
  • (C) Free radicals
  • (D) Swartz reaction
Question 9.

An α- helix is a structural feature of :

[1 Marks]
  • (A) Starch
  • (B) Sucrose
  • (C) Polypeptides
  • (D) Nucleotides
Question 10.

Assertion (A) : Low spin tetrahedral complexes are rarely observed.

Reason (R) : Crystal field splitting energy is less than pairing energy for tetrahedral complexes.

[1 Marks]
  • (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
  • (B) Assertion (A) is true, but Reason (R) is false.
  • (C) Assertion (A) is false, but Reason (R) is true.
  • (D) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).

Section C

Question 11.

What is Henry's law? Give one application of it.

[2 Marks]

Paper Details

CBSE Board Exam 2023

Class

CLASS 12-PCM

Subject

CHEMISTRY

Year

2023

Set

Set 1

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