Substance `A` isomerizes according to a first order rate law with `k = 5.0 xx 10^(-5) s^(-1)`.
(a) If the initial concentration of `A` is `1.00 M`, what is the initial rate?
(b) What is the rate after `1.00 hr` ?

Explanation

(a) Rate`= k[A] = (5.0 xx 10^(-5)s^(-1))(1.00 M)`
`= 5.0 xx 10^(-5) M s^(-1)`
(b) `k = (2.303)/(t) log.(a)/(a-x)`
`5 xx 10^(-5)s^(-1) = (2.303)/(3600 s) log.(1)/(a-x) (a-x = c_(t))`
`5 xx 10^(-5) xx 3600 = 2.303 log.(1)/(c_(t))`
`(0.18)/(2.303) = log.(1)/(c_(t))`
`log c_(t) = 0.0783`
`(a-x) = [c_(t)] = 0.835 M`
Rate `= k[a-x]`
`= 5.0 xx 10^(-5) xx 0.835 = 4.2 xx 10^(-5) M s^(-1)`