In: Chemistry
A reaction
A(aq) + B(aq) --> C(aq)
has a standard free-energy change of –3.23 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?
Using the standard free energy change formula, we can find the equilibrium constant for the reaction
Initial 0.3M 0.4M 0
Final (0.3-x)M (0.4-x)M xM
The value of 0.826 is not possible since otherwise the conc of A and B will be negative hence the correct answer is 0.145M
Concentration of C = 0.145M
Concentation of B = (0.4 - 0.145) = 0.255M
Concentation of A = (0.3 - 0.145) = 0.155M