Question & Answer: What is the oxidation state of chlorine in perchloric acid, HClO_4? A. -1 B. +3 C. +5 D. +7…..

Oxidation number of H = +1

Oxidation number of O = -2

lets the oxidation number of Cl be x

use:

1* oxidation number (H) + 4* oxidation number (O) + 1* oxidation number (Cl) = net charge

1*(+1)+4*(-2)+1* x = 0

-7 + 1 * x = 0

x = 7

So oxidation number of Cl = +7

Answer: D