1. Tardigrade
  2. Question
  3. Chemistry
  4. For an exothermic reaction, following two steps are involved. 𝐒𝐭𝐞𝐩 1. A+B → I (slow) 𝐒𝐭𝐞𝐩 2. I → AB (fast) Which of the following graphs correctly represent this reaction ?

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. For an exothermic reaction, following two steps are involved.

$𝐒𝐭𝐞𝐩 1. A+B \to I (slow)$
$𝐒𝐭𝐞𝐩 2. I \to AB (fast)$

Which of the following graphs correctly represent this reaction ?

NTA AbhyasNTA Abhyas 2020Chemical Kinetics

Solution:

In any reaction mechanism the no. of activated complexes showing maxima of potential energies is the no. of steps in that mechanism and in between these maxima is a valley where lies a more stable intermediate. There is one reaction intermediate lying at valley of two maxima representing two steps. $E_{a}$ for first step should be higher than second step as first is slow step. These requirements fulfilled by choice (ii) & not choice (i) the choice (iv) is not possible because that is for endothermic reaction $(\Delta H +$ ve $) \&$ (ii) is single step equation so not possible.