JEE Main 2020 · ChemistryNumerical answerNumerical valueMediumCalculation

JEE Main 9 January 2020, Shift 2, Chemistry Q48

Question 48 of 75 in this shift, Chemistry question 23 of 25, Section B.

A 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. The activation energy (in kJ/mol) for this process is closest to ______. (Given,

R = 8.3\ \mathrm{J\,mol^{-1}K^{-1}}

\ln\left(\frac{2}{3}\right) = 0.4

e^{-3} = 4.0

)

Official answer

3.98 to 4.00; -3.98 to -4.00

NTA final key (Jan 2020): multiple answers accepted. Any value in the range scored.

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

Same idea in other shifts

Asked 5× in all

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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 42 of the 174 JEE Main shifts held from 2017 to 2026.