Gf of H2CO3 = -616.1 KJ/mol
Gf of H20 = -237.1 KJ/mol
Gf of CO2 = - 394.4 KJ/mol
3.
A. Carbon dioxide dissolves in water to form carbonic acid. Estimate the thermodynamic equilibrium constant for this reaction using the ΔGf° values shown here.
B. Carbonic acid then ionizes in water (Ka1 = 4.5× 10-7). Ignoring Ka2, estimate K for the overall process by which CO2 and H2O form H and HCO3-.
C. What is the pressure of CO2 in equilibrium with carbonated water at 25 °C and pH = 4.57?