The correct statements among the following regarding any unimolecular reaction are-

(a) Only one reacting species is involved in the rate-determining step
(b) The order and the molecularity of the slowest step are equal to one
(c) The molecularity of the reaction is one and the order is zero
(d) Both molecularity and order of the reaction are one


1. (a, b)
2. (b, c)
3. (c, d)
4. (a, d)

Hint: The reaction can be unimolecular when one reacting species is involved

Since the reaction is a unimolecular reaction. Hence, in the slowest step i.e., in the rate-determining step, the only one reacting species is involved. Therefore, the order of reaction and molecularity of the slowest step are equal to one.