Oxidation Numbers

Question 1

What is oxidation number

Answer 1

The oxidation number (or oxidation state) tells you how many electrons an atom has donated or accepted to form an ion, or to form part of a compound

Question 2

What are the rules of oxidation number

Answer 2

-All uncombined elements have an oxidation number of 0
-The oxidation number of a simple, monatomic ion (that’s an ion consisting of just one atom) is the same as its charge.
-For molecular ions (ions that are made up of a group of atoms with an overall charge), the sum of the oxidation numbers is the same as the overall charge of the ion
-For a neutral compound, the overall charge is 0, and each atom in the compound will have its own oxidation number. The sum of these oxidation numbers is 0

Question 3

What are the rules for hydrogen oxygen and fluorine

Answer 3

-Hydrogen: Hydrogen always has an oxidation number of ‘ +1, except in metal hydrides
(MHx, where M = metal) where it’s –1 and in molecular hydrogen (H2) where it’s 0.
-Oxygen: Oxygen nearly always has an oxidation number of –2, except in peroxides (O22–) where it’s –1, and molecular oxygen (O2) where it’s 0
-Flourine has a charge of -1