Question

The rate constant for this first‑order reaction is 0.550 s−10.550 s−1 at 400 ∘C.400 ∘C. A⟶products A⟶products How long, in seconds, would it take for the concentration of AA to decrease from 0.690 M0.690 M to 0.220 M?

Answer 1

`t=2.08s`

Step-by-step explanation:

Hello,

In this case, for first order reactions, we can use the following integrated rate law:

`ln(([A])/([A]_0) )=kt`

Thus, we compute the time as shown below:

`t=-(ln(([A])/([A]_0) ))/(k)=- (ln((0.220M)/(0.690M) ))/(0.55s^(-1)) \\\\t=-(-1.14)/(0.550s^(-1))\\ \\t=2.08s`

Best regards.