Posted by MyHumPs on .
A reaction has a standard freeenergy change of –4.60 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?

Chemistry 
DrBob222,
The problem doesn't tell us what the reaction is; i.e., is this K for
A + B ==> C or for
C ==> A + B.
I am assuming it is for A + B ==> C
Use dG = RT*lnK and solve for Kc.
Then
.............A + B ==> C
I..........0.30.0.40....0
C...........x...x.....x
E........0.3x..0.4x...x
Then substitute the E line into the Kc expression and solve for x, then evaluate the other terms.