The rate expresison of some reactions are given below. Propose a probable mechanism of each of the following reactions:
(a) `2N_(2)O_(5) rarr 4NO_(2) + O_(2)`, Rate `= k[N_(2)O_(5)]`
(b) `2NO_(2) + F_(2) rarr 2NO_(2)F`, Rate `= k [NO_(2)][F_(2)]`

Explanation

(a) Rate `= k[N_(2)O_(5)]`
`{:(N_(2)O_(5)underset(RDS)overset(Slow)rarrNO_(2)+NO_(3)),(NO_(3)+N_(2)O_(5)overset("Fast")rarr3NO_(2)+F_(2)),(ulbar(2N_(2)O_(5)+rarr4NO_(2)+O_(2))):}`
(b) Rate `= k[NO_(2][F_(2)]`
`{:(N_(2)+F_(2)underset(RDS)overset(Slow)rarrNO_(2)F+F),(F+NO_(2)overset("Fast")rarrNO_(2)F),(ulbar(2NO_(2)+F_(2)rarr2NO_(2)F)):}`