molecular mass of NaF = 42gm thus, moles of NaF = 30/42 = 0.714 [NaF] = moles/volume = 0.714/1 = 0.714M [HF] = 1.00M pH = pKa + log[NaF]/[HF] pH = 3.17 + log(0.714/1.00) pH = 3.02 Solution molecular mass of NaF = 42gm thus, moles of NaF = 30/42 = 0.714 [NaF] = moles/volume = 0.714/1 = 0.714M [HF] = 1.00M pH = pKa + log[NaF]/[HF] pH = 3.17 + log(0.714/1.00) pH = 3.02.