Question

The reaction of ozone with oxygen atoms in the presence of chlorine atoms can occur by a two step process shown below:



The closest rate constant for the overall reaction

$O_{3}\left(g\right)+O^{\cdot }\left(g\right) \rightarrow 2O_{2}\left(g\right)$ is:

• A. $1.4\times 10^{20} \, L \, mol^{- 1} \, s^{- 1}$
• B. $3.1\times 10^{10} \, L \, mol^{- 1} \, s^{- 1}$
• C. $5.2\times 10^{9} \, L \, mol^{- 1} \, s^{- 1}$
• D. $2.6\times 10^{10} \, L \, mol^{- 1} \, s^{- 1}$

Answer 1

Answer: (A)

$O_{3 \left(g\right)}+Cl_{\left(g\right)}^{\cdot } \rightarrow _{}^{}O_{2 \left(g\right)}+ClO_{\left(s\right)}^{\cdot }K_{i} \\ ClO_{\left(g\right)}^{\cdot }+O_{\left(g\right)}^{\cdot } \rightarrow _{}^{}O_{2 \left(g\right)}+Cl_{\left(g\right)}^{\cdot }K_{ii}$

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$O_{3 \left(g\right)}+O_{\left(g\right)}^{\cdot } \rightarrow _{}^{}\left(20\right)_{2 \left(g\right)}K_{Rate}=K_{i}\times K_{ii}$

Overall Rate constant = K_i × K_ii

= 5.2 × 10⁹ × 2.6 × 10¹⁰

≈ 1.4 × 10²⁰ mol^-1 L s^-1