In the Arrhenius equation, when log k is plotted against 1/T, a straight line is obtained whose : (A) slope is A/R and intercept is E_a. (B) slope is A and intercept is (-E_a)/(R). (C) slope is (-E_a)/(RT) and intercept is log A. (D) slope is -E_a2·303 R and intercept is log A.

ChemistryCBSE Class 12 · Board exam 2024, set 56/1/1 · 1 mark · MCQ

CBSE Class 12 Chemistry 2024: question 9

Set in the CBSE Class 12 board exam of 2024, paper 56/1/1, section A, question 9, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q9 · 1 mark · MCQChemical Kinetics

In the Arrhenius equation, when log k is plotted against 1/T, a straight line is obtained whose :

(A)slope is $\frac{A}{R}$ and intercept is $E_{a}$ .
(B)slope is A and intercept is $\frac{- E _{a}}{R}$ .
(C)slope is $\frac{- E _{a}}{R T}$ and intercept is log A.
(D)slope is $\frac{- E _{a}}{2 \cdot 303 R}$ and intercept is log A.

Source: official question paper from cbse.gov.in (PDF). See it in the full 2024 board paper, set 56/1/1.

Hints

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

Hint 1

Take log to base 10 of $k = A e^{- E_{a} / R T}$ .

Hint 2

Compare the result with $y = m x + c$ .

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.

The Arrhenius equation in log form is $lo g k = lo g A - \frac{E _{a}}{2.303 R} \cdot \frac{1}{T}$ .
Comparing with $y = m x + c$ : slope $= - E_{a} /2.303 R$ and intercept $= lo g A$ .
1 mark

Answer: Option (D)

Where the marks are

Gives the correct slope and intercept (1 mark)

Revise the chapter

Chapter: Chemical Kinetics (notes, formulas, where marks are lost and every past question)
Topic: Arrhenius Equation and Activation Energy

Practise this chapterBoard-style questions from Chemical Kinetics, one at a time, marked against the answer key and marking points.Back to the full paper2024 board paper, set 56/1/1: every question, by section.

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CBSE Class 12 Chemistry 2024: question 9

Hints

Step-by-step solution

Revise the chapter

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