Chemistry
posted by ACDub .
A reaction A(aq)+B(aq)<>C(aq) has a standard freeenergy change of –3.35 kJ/mol at 25 °C. What are the concentrations of A, B, and C at equilibrium if, at the beginning of the reaction, their concentrations are 0.30 M, 0.40 M, and 0 M, respectively?

dG = RTlnK. Solve for K. Then
.......A + B ==> C
I..0.30.0.0.40...0
C....x....x....x
E..0.30x..0.40x..x
Substitute the E line into Keq expression and solve for x, then evaluate concn A and B.
Don't forget to use dG in J/mol and not kJ/mol 
.298, .398, .00177