Question

Cl(g) + O3(g) → ClO(g) + O2(g) slow step ClO(g) + O3(g) → Cl(g) + 2 O2(g) fast step 2 O3(g) → 3 O2(g) overall reaction ΔH = −285 kJ/molrxn Which of the following rate laws for the overall reaction corresponds to the proposed mechanism? a) Rate = k [O3]2 b) Rate = k [Cl][O3] c) Rate = k[ClO][O3]2 d)Rate= k [O2]3/ [O3]2 a) Rate = k [O3]2

b) Rate = k [Cl][O3]
c) Rate = k [ClO][O3]2
d) Rate = k [O2]3 / [O3]2

Answer 1

c) Rate = k [Cl][O3]^2

Step-by-step explanation:

To determine the rate law for the overall reaction based on the proposed mechanism, we need to look at the slowest step of the mechanism, which is the rate-determining step. In this case, the slow step is:

Cl(g) + O3(g) → ClO(g) + O2(g)

The rate-determining step defines the rate law for the overall reaction. The coefficients in this step become the exponents in the rate law.

In the slow step, we have:

Rate = k [Cl][O3]

Now, let's check the stoichiometry of the overall reaction:

2 O3(g) → 3 O2(g)

We can see that the concentration of O3 is squared in the overall reaction, so we need to square the concentration of O3 in the rate law to match the stoichiometry. Therefore, the rate law for the overall reaction is:

Rate = k [Cl][O3]^2