NEED HELP FAST!!!

Question

The rate constant for this first‑order reaction is  0.0660 s−1  at  400 ∘C.

A⟶products

After how many seconds will  17.4%  of the reactant remain?

Answer 1

In order to do this problem, you'll need to use the first-order integrated rate law: [A] = [A]₀e^-kt

What we know:

k= 0.0660 s^-1

[A] = 0.174[A]₀ -- This is because we want to find the time it takes for the concentration to be 17.4% of what we started with.

t = ?

So now we have:

0.174[A]₀ = [A]₀e^-(0.0660)t : Divide by [A]₀

==>0.174 = e^-(0.0660)t : Take ln of both sides

==>ln(0.174) = -(0.0660)t : Divide by -(0.0660)

==> t = 26.5 s