The required amount of carbonate chemistry to raise the pH of a fixed volume of liquid?

I am trying to determine the amount of sodium carbonate (Na2CO3) necessary to raise the pH of a 64000 L volume of liquid from a pH of 4.0 to a pH of 8.0? I have performed all of the carbonate dissociation calculations and have attached to this message.....I have gone over my logic and math numerous times and think I have the right answer, but I am at this point unsure. My answer seems like it derives a very small amount of carbonate necessary to accomplish the pH adjustment. Could you please check my logic and math and let me know if my answer is right or wrong....and if it is wrong, can you please explain where I might have gone wrong and show me how to derive the correct answer. ... click for more

Calculating solubility of aluminum in aluminum sulfate (AL2(SO4)3) at various pH levels?

Alum (aluminum sulfate) is used as a flocculant to floc an anionic material in a water solution at pH = 4.0 and temperature = 130 degrees F. The solubility of the alum is noted as 87 grams per 100 cc's of liquid (assuming std temp & pressure). Assume 1 liter of solution....based on this, how would I determine the actual solubility of the aluminum ion (how much dissolved vs. not) at say a pH of 3.0 vs. 4.0 vs. 5.0. Typical aluminum chemistry suggests that lower pH increases solubility given a fixed temperature of 130 degrees F ---- I also heretell that the optimal pH for alum chemistry is in the range of 4.5 to 5.0. But I do not understand this and want to know how to derive the solu... click for more

Carbonate chemistry and its use as a pH adjuster.

Please see the attached file. I am trying to determine the amount of sodium carbonate (decahydrate) needed to raise a 1 liter solution from a pH of 4.0 to 5.0? The molar mass of the Na2CO3-10H20 is given as 286.14 g/mol

Inorganic Chemistry

Inorganic Chemistry. See attached file for full problem description.

Determine solubility of boric acid (H3BO3) at various pH's

This problem indicates that 1 gram of hydrated boric acid (H3BO3) is added to 1 liter of water at pH 7.0 and at standard temperature. The solubility is stated in the problem as 5.7 grams per 100 ml of solution. A pKa is also given as 9.24. 1) What does the pKa value mean? 2) How would I determine the amount of boric acid that will dissolve at pH 7 given the conditions above? 3) And then how would I determine how much boric acid dissolved would dissolve if the pH were lowered to 6.0?