Topic 3 and 14: Redox

Question 1

Oxidation number rules

Answer 1

Element: 0
Neutral compounds: Sum to 0
Charged compounds: add up to total charge
H: +1
O: -2
Halogens: -1
Group I: +1
Group II: +2

Oxygen in peroxides: -1
Hydrogen in metal hydrides: -1

Question 2

Definition of oxidising agent

Answer 2

A species that accepts electrons, since it is reduced. There is an increase in oxidation number

Question 3

Definition of reducing agent

Answer 3

A species that loses electrons, since it is oxidised. There is a decrease in oxidation number.