CHEMISTRY!
posted by Reese on .
A zeroorder reaction has a constant rate of 3.40×10−4 M/s. If after 80.0 seconds the concentration has dropped to 6.00×10−2 M, what was the initial concentration?

Isn't the integrated rate equation for a zero order reaction the following:
[A] = [Ao]kt?
Plug and chug. 
.0000883

study more and you will know