What volume of 1M NaOH (in ml)will required to react completely with 100 gm of Oleum which is 109 % labelled ?.

SOLUTION: We know that 109% Oleum sample contains 40 gm SO3 and 60 gm H₂SO₄

                     (E _wt= SO₃=80/2=40 gm and E _wt  H₂SO₄ =98/2=49 gm)

At equivalent point 

      No of equivalent of SO₃ + No of equivalent H₂SO₄= no of equivalent of NaOH