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The order of the reaction… (Class 12 Chemistry 2023, Q6)

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ChemistryCBSE Class 12 · Board exam 2023, set 56/1/1 · 1 mark · MCQ

CBSE Class 12 Chemistry 2023: question 6

Set in the CBSE Class 12 board exam of 2023, paper 56/1/1, section A, question 6, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q6 · 1 mark · MCQChemical Kinetics

The order of the reaction is :

  1. (A)2
  2. (B)1
  3. (C)0
  4. (D)3

Source: official question paper from cbse.gov.in (PDF). See it in the full 2023 board paper, set 56/1/1.

Hints

Open one hint at a time and try again before the next.

Hint 1

This is the standard NCERT example of a particular order.

Hint 2

What controls the rate of a photochemical reaction?

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

  1. The photochemical combination of and is a zero-order reaction: its rate depends on light intensity, not on reactant concentration.

  2. Rate , so the order is 0. Option (C).

    1 mark

Answer: 0, option (C)

Where the marks are

  • Identifies it as zero order (1 mark)

Revise the chapter

  • Chapter: Chemical Kinetics (notes, formulas, where marks are lost and every past question)
Practise this chapterBoard-style questions from Chemical Kinetics, one at a time, marked against the answer key and marking points.Back to the full paper2023 board paper, set 56/1/1: every question, by section.

The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.