Question

Two substances R and S decompose in solution
independently, both following first order kinetics.
The rate constant of R is twice that of S. In an
experiment, the solution initially contained 0.5
millimoles of R and 0.25 of S. The molarities of R
and S will be equal just at the end of time equal

(a) twice the half life of R
(b) twice the half life of S
(c) the halflife of S
(d) the half life of R

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Answer 1

idk ... read the book or search the Google

Answer 2

Answer is option (1)

I hope this helps you