# Thermodynamic Cycle

What is the value for $\Delta_f G^0(\ce{Cl^-}, \ce{aq})$ in this thermodynamic cylce: Do you agree it should be (with the formation free energy of $\ce{H^+} = 0$)

$$-\Delta_f G^0(\ce{Cl^-}, \ce{aq}) + 218 + 1312 + 106 = 349 - \Delta_{Solv}G^0(\ce{Cl^-}) - \Delta_{Solv}G^0(\ce{H^+})$$

and so

$$\Delta_fG^0(\ce{Cl^-}, \ce{aq}) = 1287 + \Delta_{Solv}G^0(\ce{Cl^-}) + \Delta_{Solv}G^0(\ce{H^+})$$

(values in kJ/mol). My book however writes 1272 kJ/mol.

What is wrong?

• What are the specific concepts you're having trouble with? Please do bear in mind this FAQ on meta: "It's not enough to just show your work and ask where you went wrong. If you just need someone to check your work, you can always seek out a friend, classmate, or teacher" – EnergyNumbers Apr 30 '13 at 13:30
• The specific concept I'm having trouble with is, as I have found out, is that the book wrote a wrong value for the result (in editions 7 and 8) and the value I get is correct (in "Quanta, Matter, Change"). – TMOTTM Apr 30 '13 at 15:19