Question

The rate constant for an isomerisation reaction `Ato B` is `4.5 xx 10^(-3)min^(-1)`. If the initial concentration of A is 1M, Calculate the rate of the reaction after 1 hour.

Answer 1

Step I. Calculating of concentration after 1 h (60 min).
`k=2.303/t log ([A])_(0)/([A])_(t)`
`(log)[A]_(0)/[A]_(t)=(kt)/(2.303) = ((4.5 xx 10^(-3) min^(-1))xx (60 min))/2.303 = 0.11729`
`(log)[A]_(0)/[A]_(t)= Antilog0.1172//9 = 1.310, [A]_(t) = [A]_(0)/1.310 = 0.763M`
Step II. Calculation of rate after 1 h(60 min).
Rate after 60 min= `k[A]_(t)= 4.5 xx 10^(-3) min^(-1) xx 0.763 M= 3.4354 xx 10^(-3) M min^(-1)`