Medium INTEGER +4 / -1 PYQ · JEE Mains 2022

For the reaction P $\to$ B, the values of frequency factor A and activation energy EA are 4 $\times$ 1013 s$-$1 and 8.3 kJ mol$-$1 respectively. If the reaction is of first order, the temperature at which the rate constant is 2 $\times$ 10$-$6 s$-$1 is _____________ $\times$ 10$-$1 K.

(Given : ln 10 = 2.3, R = 8.3 J K$-$1 mol$-$1, log2 = 0.30)

Answer (integer) 225

Solution

$$ \begin{aligned} &k=A \mathrm{e}^{\frac{-E_{a}}{R T}} \\\\ &\ln k=\ln A-\frac{E_{a}}{R T} \\\\ &\Rightarrow \log \left(2 \times 10^{-6}\right)=\log \left(4 \times 10^{13}\right)-\frac{8.3 \times 10^{3}}{8.3 \times T \times 2.3} \\\\ &\Rightarrow \log (2)-6=2 \times \log (2)+13-\frac{8.3 \times 10^{3}}{8.3 \times T \times 2.3} \\\\ &\Rightarrow-19.3=-\frac{10^{3}}{T \times 2.3} \Rightarrow T=225 \times 10^{-1} \mathrm{~K} \end{aligned} $$

About this question

Subject: Chemistry · Chapter: Chemical Kinetics · Topic: Rate of Reaction

This question is part of PrepWiser's free JEE Main question bank. 96 more solved questions on Chemical Kinetics are available — start with the harder ones if your accuracy is >70%.

Drill 25 more like these. Every day. Free.

PrepWiser turns these solved questions into a daily practice loop. Chapter-wise drills, full mocks, AI doubt chat. No auto-renew.

Start free →