Model a soft drink as a solution of water with CO2 dissolved at 298.15 K. In this way we ignore the sugar, flavor, and color. The Henry’s law constant for CO2 at 298.15 K is 0.035 (mol/kg-bar).
(a) What pH and composition exist when the vapor phase is 3.5 bar absolute at room temperature ignoring O2 or N2 present? This approximates conditions in the unopened container.
(b) After the soft drink is opened, and the liquid equilibrates with atmosphere, what pH and composition exist when the CO2 vapor mole fraction is yCO2 = 0.0003 (the normal ambient value) and the pressure is 1 bar?