Question

The rate constant for a certain reaction is k = 5.50×10−3 s−1 . if the initial reactant concentration was 0.550 m, what will the concentration be after 2.00 minutes? express your answer with the a

Answer 1

Answer: 0.19 m

Explanation:- Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.

`Rate=k[A]^x` (1)

k= rate constant

x= order= 1

As the units of
`k=s^(−1)` , the reaction follows first order kinetics.

`Rate= 5.50* 10^(-3)* [0.550]^1=0.003ms^(-1)`

Also rate is the change in concentration of reactants or products in a given time.

`Rate=(-d[A])/(dt)` (2)

Equating (1) and (2)

`Rate=(-d[A])/(dt)=(-[A_f-A_i])/(dt)=k[A]`

`0.003=-([A_f-0.550])/(120s)`

`A_f=0.19m`