Formulate two equations to show how nitrogen(II) oxide, NO, catalyses the destruction of ozone.

Suggest why the loss of ozone is an international environmental concern.

${\text{NO}} \bullet {\text{(g)}} + {{\text{O}}_{\text{3}}}{\text{(g)}} \to {\text{N}}{{\text{O}}_{\text{2}}} \bullet {\text{(g)}} + {{\text{O}}_{\text{2}}}{\text{(g)}}$

${\text{N}}{{\text{O}}_{\text{2}}} \bullet {\text{(g)}} + {\text{O}} \bullet {\text{(g)}} \to {\text{NO}} \bullet {\text{(g)}} + {{\text{O}}_{\text{2}}}{\text{(g)}}$
OR
${\text{N}}{{\text{O}}_{\text{2}}} \bullet {\text{(g)}} + {{\text{O}}_{\text{3}}}{\text{(g)}} \to {\text{NO}} \bullet {\text{(g)}} + {\text{2}}{{\text{O}}_{\text{2}}}{\text{(g)}}$

Allow representation of radicals without $\bullet$ if consistent throughout.

[2 marks]

«loss of ozone» allows UV radiation to penetrate atmosphere/reach earth

UV radiation causes skin cancer
OR
UV radiation causes tissue damage

[2 marks]