Question

What is the oxidation number of Chlorine in NaClO4?

-1
+7
-5
+1

Answer 1

Take note that for basis, oxygen always has oxidation number of -2 and group 1, 2 and 3 elemets, have the oxydation number equal tothe number of thei groups. But this is only when they are in a compoud.
The algebraic sum of the oxidation numbers must be equal to zero.
NB: any chemical ELEMENT by itself in a chemical equaion has a oxydation number of 0.
For this compound, we shall have +1+x-(2*4)=0 or x=+7

Answer 2

Thank so much for your answer and explanation. Much appreciated!

Answer 3

My pleasure.