The % of free SO3 in an Oleum sample is 20%. What is its labelling?
104.5
105.6
107.8
109.1
% of free SO3 in Oleum = 20 %
Weight of SO3 in the 100g Oleum sample = 20 g
Moles of SO3 present = 20/80 = 0.25
Moles of H2O added = 0.25 X 18
Weight of H2O added = 4.5 g
% labelling of Oleum= (100+ 4.5) = 104.5 %
Thus, the correct option is (1)