Chemistry · Chemical Kinetics

JEE Main 2026 — 2 April, Morning Shift — Question 59

For reaction A→P\mathrm{A} \rightarrow \mathrm{P}, rate constant k=1.5×103 s−1\mathrm{k}=1.5 \times 10^{3} \mathrm{~s}^{-1} at 27∘C27^{\circ} \mathrm{C}. If activation energy for the above reaction is 60 kJ mol−160 \mathrm{~kJ} \mathrm{~mol}^{-1}, then the temperature (in ∘C{ }^{\circ} \mathrm{C} ) at which rate constant, k=4.5×103 s−1\mathrm{k}=4.5 \times 10^{3} \mathrm{~s}^{-1} is ____\_\_\_\_ . (Nearest integer) Given : log⁡2=0.30,log⁡3=0.48,R=8.3 J K−1 mol−1\log 2=0.30, \log 3=0.48, \mathrm{R}=8.3 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}, ln⁡10=2.3\ln 10=2.3

Answer: 41

Numerical answer — enter this value.

Step-by-step solution

ℓn(K2 K1)=EaR[T2−T1 T1 T2]\quad \ell \mathrm{n}\left(\frac{\mathrm{K}_{2}}{\mathrm{~K}_{1}}\right)=\frac{\mathrm{E}_{\mathrm{a}}}{\mathrm{R}}\left[\frac{\mathrm{T}_{2}-\mathrm{T}_{1}}{\mathrm{~T}_{1} \mathrm{~T}_{2}}\right]

ln⁡(4.5×1031.5×103)=60×1038.3[ T2−300300.T2]ln⁡3=60×1038.3[ T2−300300.T2]⇒T2=314.4 K⇒t=41.4∘C\begin{aligned} & \ln \left(\frac{4.5 \times 10^{3}}{1.5 \times 10^{3}}\right)=\frac{60 \times 10^{3}}{8.3}\left[\frac{\mathrm{~T}_{2}-300}{300 . \mathrm{T}_{2}}\right] & \ln 3=\frac{60 \times 10^{3}}{8.3}\left[\frac{\mathrm{~T}_{2}-300}{300 . \mathrm{T}_{2}}\right] & \Rightarrow \mathrm{T}_{2}=314.4 \mathrm{~K} & \Rightarrow \mathrm{t}=41.4^{\circ} \mathrm{C} \end{aligned}

Answer key and solution verified before publishing.

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Exam
JEE Main 2026
Subject
Chemistry
Chapter
Chemical Kinetics
Topic
Arrhenius Equation