3
Table 3 3: Units of rate constant
Reaction
Order
Units of rate constant
Zero order reaction
0
(
)
1
1
1
10
mol L
1
mol L s
s
mol L
−
−
−
−
×
=
First order reaction
1
(
)
1
1
11
mol L
1
s
s
mol L
−
−
−
×
=
Second order reaction
2
(
)
1
1
1
12
mol L
1
mol L s
s
mol L
−
−
−
−
×
=
Identify the reaction order from each of the following rate constants (i) k = 2 3 × 10–5 L mol–1 s–1
(ii) k = 3 × 10–4 s–1
(i) The unit of second order rate constant is L mol–1 s–1, therefore
k = 2