Calculate the pH of a solution made by

(a) Adding 12.5 g sodium nitrite to 6.0 g nitrous acid and adding water until the fi nal volume is 1.00 L.

(b) Adding 45.0 g formic acid to 20.0 g sodium formate and adding enough water to make 1.00 L of buffer.

(c) Adding 15.00 g sodium acetate and 12.50 g acetic acid to enough water to make 0.500 L of solution.