pH = pKa + log (Cbase/Cacid)
pH = 1.8x10-4 + log (Cbase/Cacid)
pH = pKa + log(m(HCOONa)/68 / m(HCOOH)/46)
m(HCOONa)/m(HCOOH) * 0.676 = 10pH-pKa
If any of two quantities m (HCOONa) or m (HCOOH) is provided, the one may calculate how many grams of formic acid and sodium formate should be added to the solution to prepare the buffer.