HCl can be produced by the exothermic reaction H2(g)+2ICl(g)→2HCl(g)+I2(g) . A proposed mechanism for the reaction has two elementary steps as shown below.

Step 1: H2(g)+ICl(g)→HI(g)+HCl(g) (slow)

Step 2: HI(g)+ICl(g)→HCl(g)+I2(g) (fast)
(d) Write a rate law for the overall reaction that is consistent with the proposed mechanism.
(e) On the incomplete reaction energy diagram below, draw a curve that shows the following two details.

The relative activation energies of the two elementary steps
The enthalpy change of the overall reaction