Oxidation Numbers (Day 2)

Question 1

What is an Oxidation Number?

Answer 1

An Oxidation number is a number assigned to an individual atom or ion in a substance using a set of rules.

Question 2

What are some of the rules when assigning Oxidation Numbers?

Answer 2

1. A pure element has oxidation number 0 → Fe(s) or O in O2 has ox#=0.
2. Oxidation number of an ion is the charge on the ion → Mg+2 has ox # = +2, Cl- has ox #= -1.
3. The oxidation number of hydrogen is generally +1, in metal hydrides it is -1.
4. Oxidation number of oxygen is generally -2.
5. The sum of all oxidation numbers is a compound = 0
   6) the sum of all oxidation numbers in an ion = the charge on the ion.