Question

Propose a plausible two-step mechanism for the reaction given below with the steps provided. A+2B → C + E (slow) D + B → E (fast) 28 → C + E (slow) A + E → D (fast) A+B→C+D(slow) A+B→C+E(slow) A+B→C+E(fast) A+B→C+D(fast) D→C+E(fast) Overall Reaction: A+2B → C + E Experimentally Determined Rate Law rate = MA]

Answer 1

Answer : The the mechanism for the reaction is:

Step 1 :
`A+B\rightleftharpoons C+D` (Slow)

Step 2 :
`D+B\rightarrow E` (fast)

Explanation :

Rate law : It is defined as the expression which expresses the rate of the reaction in terms of molar concentration of the reactants with each term raised to the power their stoichiometric coefficient of that reactant in the balanced chemical equation.

As we are given the overall reaction is:

`A+2B\rightleftharpoons C+E`

The rate law expression is:

`Rate=k[A][B]`

The rate law expression for overall reaction should be in terms of A and B.

As we know that the slow step is the rate determining step.

Now we have to determine the mechanism for the reaction.

The mechanism for the reaction is:

Step 1 :
`A+B\rightleftharpoons C+D` (Slow)

Step 2 :
`D+B\rightarrow E` (fast)