The rate law for the decomposition of aqueous hydrogenperoxide
(H2O2) at 70 degrees celcius is first order in
with k=.0347 min to the negative 1.
A) Calculate the half-life (t1/2) for this reaction at
70degrees C
B) Given that the initial concentration of H202 is
.300Mcalculate the concentration of H2O2 after 60 minutes
haselapsed.

Respuesta :

Answer:

[tex]t_{1/2}=19.98\ min[/tex]

[tex][A_t]=0.037\ M[/tex]

Explanation:

(a)

Given that:

Rate constant, k = 0.0347 min⁻¹

The expression for the half-life is:-

[tex]t_{1/2}=\frac{\ln 2}{k}[/tex]

Where, k is rate constant

So,  

[tex]t_{1/2}=\frac{\ln 2}{0.0347}\ min[/tex]

[tex]t_{1/2}=19.98\ min[/tex]

(b)

Using integrated rate law for first order kinetics as:

[tex][A_t]=[A_0]e^{-kt}[/tex]

Where,  

[tex][A_t][/tex] is the concentration at time t

[tex][A_0][/tex] is the initial concentration

Given that:

The rate constant, k = [tex]0.0347[/tex] min⁻¹

t = 60 min

Initial concentration [tex][A_0][/tex] = 0.300 M

Final concentration [tex][A_t][/tex] =?

Applying in the above equation, we get that:-

[tex][A_t]=0.300\times e^{-0.0347\times 60}\ M[/tex]

[tex][A_t]=0.3\times \frac{1}{e^{2.082}}\ M[/tex]

[tex][A_t]=0.037\ M[/tex]