Chemistry
posted by Joanna .
The rate constant for a certain reaction is = 4.30×10−3 s^1. If the initial reactant concentration was 0.400 M , what will the concentration be after 19.0 minutes?
Rate would be first order therefore I used.
A=A initial*e^kt
I keep getting .0030 M but supposely I am wrong can anyone help me or tell me what I am doing wrong?

19 minutes is 1140 s, so kt = 4.90
The molarity should decrease to 0.400*e^4.9 = .0030 (M)
I agree with your answer