The rate law expresses the relationship of the rate of a reaction to the rate constant and the concentration of the reactants raised to some powers for the general reaction.
`aA+bBtocC+dD`
Rate law takes the form
`r=k[A]^(x)[B]^(y)`
where x and y are number that must be determined experimentely k is the rate constant and [A] and [B] are concentration of A & B respectively.
Gaseous reaction `AtoB+C` follows first order kinetics concentration of A changes from A changes from 1M to 0.25M in 138.6 min.Find the rate of reaction when conc. of A is 0.1 M.

Options

A. `10^(-2) M "min"^(-1)`
B. `10^(-3) M "min"^(-1)`
C. `10^(-5) M "min"^(-1)`
D. `10^(-2) M "min"^(-1)`

Answer

B

Explanation

`r=k[A]=0.693/69.3xx0.1=10^(-3) M, t_(1//2)=69.3` min