Learn

Saturday, 31 October

JEE Main 2026 · ChemistryMultiple choiceTwo statementsMediumMulti-step

JEE Main 8 April 2026, Shift 2, Chemistry Q57

Question 57 of 75 in this shift, Chemistry question 7 of 25, Section A.

Given below are two statements : R=8.314 J K−1 mol−1R = 8.314\ \mathrm{J\,K^{-1}\,mol^{-1}} and 1 cal = 4.2 J Statement I : When Ea = 12.6 kcal/mol, the room temperature rate constant is doubled by a 10 ∘^\circC increase in temperature (298 K to 308 K) Statement II : For a first order reactions A→B\mathrm{A \rightarrow B}, [graph of t1/2t_{1/2}/s (y-axis) vs [A]0[\mathrm{A}]_0/mol L−1^{-1} (x-axis): straight line through the origin with positive slope] Here [A]0[\mathrm{A}]_0 is the initial concentration of A and t1/2t_{1/2} is half life of reaction. In the light of the above statements, choose the correct answer from the options given below :

The figure, in words

Graph of t_1/2 (s) on y-axis vs [A]_0 (mol L^-1) on x-axis: a straight line rising from the origin.
  1. (1)Both Statement I and Statement II are true
  2. (2)Both Statement I and Statement II are false
  3. (3)Statement I is true but Statement II is falseOfficial answer
  4. (4)Statement I is false but Statement II is true

Official answer

Option 3

NTA final key.

Chapter
Chemical Kinetics
Topic
Arrhenius Equation
Idea tested
Two-Point Arrhenius Equation

Same idea in other shifts

Asked 7× in all
  1. 2 Apr 2026, Shift 1 · Q74For reaction A→P\mathrm{A\rightarrow P}, rate constant k=1.5×103 s−1k=1.5\times10^3\ \mathrm{s^{-1}} at 27∘27^\circC If activation energy for the above…MediumNumerical value
  2. 29 Jun 2022, Shift 1 · Q85The activation energy of one of the reactions in a biochemical process is 532611 J mol−1532611\ \mathrm{J\ mol^{-1}}. When the temperature falls from…MediumNumerical value
  3. 27 Aug 2021, Shift 2 · Q59The first order rate constant for the decomposition of CaCO3\mathrm{CaCO_3} at 700 K is 6.36×10−36.36 \times 10^{-3} s−1\mathrm{s^{-1}} and…MediumNumerical value
  4. 25 Feb 2021, Shift 2 · Q57The rate constant of a reaction increases by five times on increase in temperature from 27∘^\circC to 52∘^\circC. The value of…MediumNumerical value
  5. 9 Jan 2020, Shift 2 · Q48A sample of milk splits after 60 min. at 300 K and after 40 min. at 400 K when the population of lactobacillus acidophilus in it doubles.…MediumNumerical value
  6. 6 Sep 2020, Shift 2 · Q48The rate of a reaction decreased by 3.555 times when the temperature was changed from 40 °C to 30 °C. The activation energy (in kJ…MediumNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.