Most reactions in
solution are between TWO REACTANTS and thus are Second Order. However, water and
oxygen are present in unlimited supply and their
concentration remains constant throughout - reaction appears to be First order.
D +
H2 O ® hydrolysis
products
- d [ D ] / dt = k2 [ D ] [H2 O ] » k1 [ D ]
where
k1 = k2 [H2 O ]
D +
O2 ® oxidation products
- d [ D ] / dt = k2’ [ D ] [O2 ] » k1’ [ D ]
where
k1’ = k2’ [O2 ]