Sodium hydroxide solutions can be used to remove carbon dioxide from gaseous streams. A 0.3M solution...

 

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Sodium hydroxide solutions can be used to remove carbon dioxide from gaseous streams. A 0.3M solution of sodium hydroxide is allowed to equilibrate with the atmosphere in an analytical laboratory where the temperature is kept at 25C. The partial pressure of carbon dioxide in the atmosphere, Pc02, is 10-35 atm, and its Henry's Law constant KH = 10-5 mol.L/atm. Determine the pH and the total acid concentration, CT.C03, of the solution when equilibrium with the atmosphere is attained. How do you expect the concentration CT,CO3 to vary with the initial concentration of NaOH in solution? Hint: Follow the six steps method discussed in class to write all pertinent chemical reactions and obtain sufficient number of equations to solve for all unknown concentrations (electroneutrality, mass balances, equilibrium equations for all chemical reactions and partition between phases, etc.). Express each species concentration in the electroneutrality equation in terms of pH and constants to derive a final equation with the pH as the only unknown. Sodium hydroxide solutions can be used to remove carbon dioxide from gaseous streams. A 0.3M solution of sodium hydroxide is allowed to equilibrate with the atmosphere in an analytical laboratory where the temperature is kept at 25C. The partial pressure of carbon dioxide in the atmosphere, Pc02, is 10-35 atm, and its Henry's Law constant KH = 10-5 mol.L/atm. Determine the pH and the total acid concentration, CT.C03, of the solution when equilibrium with the atmosphere is attained. How do you expect the concentration CT,CO3 to vary with the initial concentration of NaOH in solution? Hint: Follow the six steps method discussed in class to write all pertinent chemical reactions and obtain sufficient number of equations to solve for all unknown concentrations (electroneutrality, mass balances, equilibrium equations for all chemical reactions and partition between phases, etc.). Express each species concentration in the electroneutrality equation in terms of pH and constants to derive a final equation with the pH as the only unknown.