Propanoic acid that, along with its sodium salt, can be used to make a buffer that has a pH of 5.25. If you have 532.9 mL of a 0.250 M solution of that acid, how many grams of the corresponding sodium salt do you have to dissolve to obtain the desired pH?

Answer 1

pH = pKa + log (base)/(acid)
5.25 = pKa + log (base)/(M x L)
Solve for base and since the acid is in mols, the base will be in mols.
Then mols = grams/molar mass. You know molar mass and mols, solve for grams. That will be the number of grams of the salt to add to the 532.9 mL of the acid.