Question

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 :
A. `L mol^(-1) s^(-1)`
B. No unit
C. mol `L^(-1) s^(-1)`
D. `s^(-1)`

Answer 1

Correct Answer - a
`2 A + B to ` Product
When conc., of B is doubled , the half life did not change , hence reaction is of first w.r.t. B.
When concentration of A is doubled , reaction rate is doubled , hence reaction is of first order w.r.t. A .
Hence , over all order of reaction is 1 + 1 = 2 .
So , unit of rate constant `mol^(-1)` lit `s^(-1)` .