Question

How would one calculate the equilibrium pressure of Sodium bicarbonate and citric acid in water (think Alka Seltzer), reacting in a closed volume. The pressure builds up to a point, where the reaction slows due to pressure build up. How do I calculate the equilibrium pressure as a function of temperature?

Answer 1

YOu have to calaculate the equilibrium concentrations in solution, which makes a difficult analytical problem, as the amount of carbon dioxide in solution is itself a function of the partial pressure (which you want to monitor).

Keq will depend on temperature,
solubility of CO2 will depend on pressure and temperature.

Goodluck.