Carbonate is commonly used to buffer household detergent solutions to a pH of 9.0. How many grams on NaHCO3 and how many grans of NA2CO3 are needed to prepare 0.75L of a 100mM solution? The 2nd pKa of carbonic acid is 10.33.
pH = pK2 + log (base)/(acid)
9.0 = 10.33 + log b/a
solve for b/a which is equation 1 but b and a will be mols and no concentration.
The second equation is a + b = 0.75L x 0.100M = ? mols
Solve the two equations for b and a and convert mols to grams from mols = grams/molar mass