Easy INTEGER +4 / -1 PYQ · JEE Mains 2021

If the activation energy of a reaction is 80.9 kJ mol$-$1, the fraction of molecules at 700 K, having enough energy to react to form
products is e$-$x. The value of x is __________. (Rounded off to the nearest integer) [Use R = 8.31 J K$-$1 mol$-$1]

Answer (integer) 14

Solution

E<sub>a</sub> = 80.9 kJ/mol<br><br>Fraction of molecules able to cross energy barrier = e<sup>$-$E<sub>a</sub>/RT</sup> = e<sup>$-$x</sup><br><br>x = ${{{E_a}} \over {RT}} = {{80.9 \times 1000} \over {8.31 \times 700}} = 13.91$<br><br>$\Rightarrow$ x $\simeq$ 14

About this question

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

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