Oxidation state rules

Question 1

Rule 1?

Answer 1

Atoms in the free, uncombined, element have an oxidation state of 0

Question 2

Rule 2?

Answer 2

In simple ions, oxidation state is the same as the charge on the ion

Question 3

Rule 3?

Answer 3

The oxidation state of all the atoms in a neutral compound must add up to 0

Question 4

Rule 4?

Answer 4

Oxidation states of all the atoms in a polyatomic ion must add up to the charge on the ion

Question 5

Rule 5?

Answer 5

Usual oxidation state for an element in a compound is the same as the charge on its most common ion

Question 6

Rule 6?

Answer 6

F has the oxidation state of -1 in all its compounds as it is the most electronegative element

Question 7

Rule 7?

Answer 7

O has the oxidation state -2 Except:
1. when in peroxides like H2O2 where it is -1
2. When bonded to F it is positive as it is less electronegative than fluorine

Question 8

Rule 8?

Answer 8

Cl has the oxidation state of -1 except when it is bonded to the more electronegative F and O

Question 9

Rule 9?

Answer 9

H has the oxidation state of +1 except when bonded to the group 1 and 2 metals when it forms ionic hydrides

Question 10

Rule 10?

Answer 10

The oxidation state of a transition metals in a complex ion ca be worked out from the charge on the ligands