The rate constant for this first‑order reaction is 0.460 s − 1 at 400 ∘ C. A ⟶ products How long, in seconds, would it take for the concentration of A to decrease from 0.680 M to 0.370 M?

Respuesta :

Answer:

1.32 seconds would take for the concentration of A to decrease from 0.680 M to 0.370 M.

Explanation:

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]0.460[/tex] s⁻¹

Initial concentration [tex][A_0][/tex] = 0.680 M

Final concentration [tex][A_t][/tex] = 0.370 M

Time = ?

Applying in the above equation, we get that:-

[tex]0.370=0.680\times e^{-0.460\times t}[/tex]

[tex]0.68e^{-0.46t}=0.37[/tex]

[tex]68e^{-0.46t}=37[/tex]

[tex]-0.46t=\ln \left(\frac{37}{68}\right)[/tex]

[tex]t=1.32\ s[/tex]

1.32 seconds would take for the concentration of A to decrease from 0.680 M to 0.370 M.