What is the O.N. of Cl in ?
3
4
5
6
Rules for Oxidation Number -
In all its compounds, flourine has an oxidation number of -1. Other halogens (Cl, Br, and I) also have an oxidation number of -1, when they occur as halide ions in their compound.
2 O.N.(Cl) + 6 O.N.(O) =0
O.N.(Cl) = +6