Question

A first-order reaction has a rate constant of 0.241/min. if the initial concentration of a is 0.859 m, what is the concentration of a after 10.0 minutes?

Answer 1

Answer: 0.077 M

Step-by-step explanation:

Expression for rate law for first order kinetics is given by:

`k=(2.303)/(t)\log(a)/(a-x)`

where,

k = rate constant =
`0.241minute^(-1)`

t = time taken for decay process = 10 minutes

a = initial amount of the reactant= 0.859 M

a - x = amount left after decay process =?

Putting values in above equation, we get:

`0.241 minutes^(-1)=(2.303)/(10.0)\log(0.859)/(a-x)`

`(a-x)=0.077M`

Thus the concentration of a after 10.0 minutes is 0.077 M.