A compound contains 31.91% potassium; 28.93% chlorine and the rest oxygen. What is the chemical formula of the compound? [K = 39, Cl = 35.5, O = 16]

A. KClO4
B. KClO
C. KClO2
D. KClO3

Correct Answer:

Option D – KClO3

Explanation

K- (31.91%), Mole = 31.91/39 =0.8182
Cl-(28.93%), Mole = 28.93/35.5 = 0.815
O-(39.16%), Mole = 39.6/16 = 2.448
K = 0.8182/0.815 = 1
Cl = 0.815/0.815 = 1
O = 2.448/0.815 = 3