Step 1:

(a)

The chemical equation is $\"\"$ .

The proposed mechanism is

$\"\"$

Consider the two elementary steps as follows:

$\"\"$

Add the two elementary reactions.

$\"\"$

As $\"\"$ appears in equal amount on the both sides of the reaction, it can be eliminated.

$\"\"$ .

Hence, the proposed mechanism can yield the chemical equation.

Step 2:

(b)

Molecularity :

The molecularity of a reaction is defined as the number of molecules or ions that participate in the rate determining step.

The molecularity of first elementary step is unimolecular since only one molecule $\"\"$ is involved in rate determining step.

The molecularity of second elementary step is bimolecular since only two molecules $\"\"$ and $\"\"$ are involved in rate determining step.

Hence, first elementary step is unimolecular and second elementary step is bimolecular.

Step 3:

(c)

Chemical intermediate:

Any chemical substance produced during the conversion of some reactant to a product is intermediate. \ \

Here $\"\"$ is produced during the conversion. \ \

$\"\"$ is the chemical intermediate. \ \

Solution:

(a) Yes, the proposed mechanism can yield the chemical equation.

(b) First elementary step is unimolecular and second elementary step is bimolecular.