Question

Based on the data given and a rate constant of 0.031 M?1?min?1, calculate the time at which the concentration of reactant A will be 0.175M .

t (min) [A]t(M)

0.00 0.500

20.0 0.382

40.0 0.310

60.0 0.260

80.0 0.2

Answer 1

After 120.0 minutes the the concentration of reactant A will be 0.175 M

Step-by-step explanation:

Rate constant of the reaction = k =
`0.03 M^(-1) min^(-1)`

From the units of rate constant is very much obvious that reaction of second order kinetics.

Initial concentration of reactant =
`[A_o]=0.50M`

Final concentration of A after time t =
`[A]=0.175 M`

t = ?

Integrated rate law for second order kinetics is given by:

`(1)/([A])=kt+(1)/([A_0])`

`(1)/(0.175  M)=0.031 M^(-1) min^(-1)* t+(1)/(0.500 M)`

t = 119.8 min ≈ 120.0 min

After 120.0 minutes the the concentration of reactant A will be 0.175 M