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When a 28.0 mL sample of a 0.339 M aqueous nitrous acid solution is titrated with a 0.423 M aqueouspotassium hydroxide solution, what is the pH at the midpoint in the titration?
Expert Answer
Answer
HNO2 , Ka = 5.6×10–4
at mid point moles of acid = moles of salt formed
so pH =pKa
pKa = -log Ka
pKa = -log ( 5.6×10–4)
pKa = 3.25
pH = 3.25
