Question

How would you assign an oxidation number to HCl?

Answer 1

How would I assign individual oxidation numbers to the constituent atoms of hydrochloric acid? Attend.

Explanation:

We have a `H-Cl` molecule; when we break the bond (conceptually!) the 2 bonding electrons are assumed to go to the most electronegative atom, which is `Cl`. So we get `H^+` and `Cl^-`. By definition, the oxidation number is the charge left on the central atom when all of the bonding electrons pairs are broken. Therefore, oxidation number of `H` `=` `+I`, and oxidation number of `Cl` `=` `-I`.

Try doing this for `F-Cl`, `H_2O`, and `CF_4`.

Answer 2

The oxidation number of hydrogen is `"+1"` and the oxidation number of chlorine is `"-1"`.

Explanation:

The sum of oxidation numbers in a compound is zero. So the oxidation number of the compound `"HCl"` is zero.

In a compound, hydrogen has an oxidation number of `"+1"`.

Since the sum of the oxidation numbers of hydrogen and chlorine must equal zero, the oxidation number of chlorine must be `"-1"`.

`1(+1)+1(-1)=0`

`"H"^(+1)"Cl"^(-1)"`