The following results were obtained during kinetic studies of the reaction : `2A+Bto` Products

The time (in minutes) required to consume half of A is _______________.

Answer

5

Explanation

On changing the concentration of B, there is no effect on the initial rate of the reaction.
However, on doubling the conc. Of A the reaction rate doubled.
`:.` The reaction must be first order w.r.t A
`R=k[A]^(x)[B]^(y)`
`6.93xx10^(-3)=k[0.10]^(x)[0.1]^(y)implies6.93x10^(-3)=k[0.10]^(x)[0.25]^(y)`
`1.380xx10^(-2)=k[0.20]^(x)[0.30]^(y):.x=1,y=0`
Also, `k=(6.93xx10^(-3))/0.1=6.93xx10^(-2)`
`t_(0.5)=0.693/(2k)=0.693/(2xx6.93xx10^(-2))=5`