The rate constant of a reaction with respect to the reactant A is 6 `"min"^(-1)`. If we start with [A] = `0.8 mol L^(-1)`, when would [A] reach the value of `0.08 mol^(-1)`?

Explanation

Since the rate constant units for first order is in `"min"^(-1)`.
Accordingly, for the first order reaction,
`t=2.303/k log (a/(a-x))`
`a=0.8 mol L^(-1)`,
`(a-x)=0.008 mol L^(-1)`,
`k=6 "min^(-1)"`
`t = (2.303)/(6"min"^(-1)) log ((0.8 mol L^(-1))/(0.08 mol L^(-1))) = 2.303 / (6 "min"^(-1)) log 10 = 0.38 min`