JEE Main 2021 · ChemistryNumerical answerNumerical valueMediumCalculation

JEE Main 25 February 2021, Shift 2, Chemistry Q57

Question 57 of 90 in this shift, Chemistry question 27 of 30, Section B.

The rate constant of a reaction increases by five times on increase in temperature from 27

^\circ

C to 52

^\circ

C. The value of activation energy in kJ mol

^{-1}

is ________. (Rounded-off to the nearest integer) [R

=8.314

J K

^{-1}

mol

^{-1}

]

Official answer

NTA final key.

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

Same idea in other shifts

Asked 7× in all

2 Apr 2026, Shift 1 · Q74For reaction $\mathrm{A\rightarrow P}$ , rate constant $k=1.5\times10^3\ \mathrm{s^{-1}}$ at $27^\circ$ C If activation energy for the above…MediumNumerical value
8 Apr 2026, Shift 2 · Q57Given below are two statements : $R = 8.314\ \mathrm{J\,K^{-1}\,mol^{-1}}$ and 1 cal = 4.2 J Statement I : When Ea = 12.6 kcal/mol, the…MediumTwo statementsHas a figure
29 Jun 2022, Shift 1 · Q85The activation energy of one of the reactions in a biochemical process is $532611\ \mathrm{J\ mol^{-1}}$ . When the temperature falls from…MediumNumerical value
27 Aug 2021, Shift 2 · Q59The first order rate constant for the decomposition of $\mathrm{CaCO_3}$ at 700 K is $6.36 \times 10^{-3}$ $\mathrm{s^{-1}}$ and…MediumNumerical value
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 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. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.