Question

An oxide of sulphur contains 50 % S. What will be its emprical formula ?

(1)	SO
(2)	SO2
(3)	SO3
(4)	S2O3

Answer 1

(2)
Percentage of S = 50
So, Percentage of O = 50
Therefore, 50 g of S and O are present.
Moles of S = 50/32 = 1.5625
Moles of O =50/16 = 3.125
Divide both by smaller one (ie 1.5625)
S = 1.5625/1.5625 = 1
O = 3.125/1.5625 = 2
So, empirical formula = SO₂
​​​​
So the Answer is (2)