Consider a reaction, `2A + B rarr` Products
When concentration of `B` alone was doubled, the half-life did not change. When the concentration of `A` alone was doubled, the rate increased by two times. The unit of rate constant for this reaction is :

Options

A. `s^(-1)`
B. `"L mol"^(-1)s^(-1)`
C. no unit
D. `"mol L"^(-1)s^(-1)`

Answer

B

Explanation

On doubling the concentration of B, half life period does not change. The means that the reaction is of first order with respect to B. On doubling the concentration of order. A, the rate is doubled, this means that the reaction is of first order with respect to A i.e.,
Rate `= k[A][B]`
`:.` order of reaciton = 2
`:.` units of `k = "L mol"^(-1)s^(-1)`