Question

Rearranged and Combined Equation:? Br(g)+O3(g) ------> BrO(g)+O2(g) Br(g)+2O2(g)-----> BrO (g)+O3(g)

Atomic halogens greatly speed the rate of ozone destruction through several steps in which they themselves are consumed and then regenerated. Rearrange the following chemical equations as needed and then combine them to show how Cl atoms react with ozone to form oxygen but are not consumed in the overall process. Neither the Br atom nor the BrO molecule should appear in the final chemical equation.

Answer 1

`3O_2(g) stackrel(hnu)rarr 2O_3(g)`

Explanation:

`Br(g) + O_3(g) rarr BrO(g)+O_2(g)` `(i)`

`Br(g) + 2O_2(g) rarr BrO(g)+O_3(g)` `(ii)`

Now a quick inspection establishes that both equation CONSERVE mass and charge, as is required.

And if we subtract `(i)` from `(ii)` them algebraically, we get....

`cancel(BrO(g))+O_2(g)+cancel(Br(g)) + 2O_2(g) rarr cancel(BrO(g))+O_3(g)+cancel(Br(g)) + O_3(g)`

...to give after cancellation....

`3O_2(g) rarr 2O_3(g)`

Is this reaction favoured by entropy?