A zero-order reaction has a constant rate of 3.20×10^−4 M/s. If after 35.0 seconds the concentration has dropped to 9.00×10^2M , what was the initial concentration?

Answer 1

[A] = [A]^o - kt
solve for [A]^o. You have k, t, and [A].

Answer 2

9.00 x 10^-2= (-3.20 x 10^-4)(35)+A
9.00 x 10^-2= (-.0112)+A
9.00 x 10^-2+.0112=A
A= .1012