posted by meraki .
Calculate the delta G naught prime f (free energy of formation) of the following compounds at 25 degrees celsius.
ethyl acetate (ethyl acetate + H2O <=> ethanol + acetate- + H): delta G naught prime =-19.7 kj/mol); the pka of acetic acid is 4.76)
Free Energies for:
H2O: -237.2, ethanol: -181.5, acetate: 369.2, H+: 0)
the solution is as follows:
free ENG f (ethanol) + free ENG f (OAc-) + free ENG f (H+) -free ENG f (H2O) - delta G prime
-181.5-369.2 + 0 + 237.2 - (delta G naught) = -313.5 - (delta G naught prime) + 20.1 RT
=-313.5 + 19.7 + 49.88 = -244.0 kj/mol
I don't understand where the 20.1 is coming from, can someone explain?