1What happens when an element is oxidised?
It either gains oxygen atoms, increases in oxidation state, loses electrons or loses hydrogen atoms
2What happens when an element is reduced?
It either loses oxygen atoms, decreases in oxidation state, gains electrons or gains hydrogen atoms
3What is rule #0 for the calculation of oxidation state
Oxidation state of atom(s) in elemental state is zero.
4What is rule #1 & 3 for the calculation of oxidation state
Standard oxidation states based on common valency are observed for elements part of compounds in groups 1 & 2 as well as 13-17
5What is rule #2 for the calculation of oxidation state
Oxidation state for fluorine, hydrogen & oxygen are -1, +1 except in metal hydrides (-1) & -2 except in peroxides (-1) & superoxides (-0.5) respectively
6What is rule #4 for the calculation of oxidation state
Oxidation state is determined by the ion’s charge except for transition metals with oxidation state in roman numerals
7What is rule #5 for the calculation of oxidation state
Sum of oxidation state of all elements in a chemical formula of a compound = 0
8What is rule #6 for the calculation of oxidation state
Sum of oxidation state of all elements in polyatomic ions is equal to its charge
9What is an oxidising agent?
It oxidises another substance and is itself reduced in the process
10What is a reducing agent?
It reduces another substance and is itself oxidised in the process
11What is the test for oxidising agent and its results
Add potassium iodide solution into the unkown solution. If the colourless potassium iodide solution turns brown, the unkown is an oxidising agent
12What is the test for reducing agent and its results
Add acidified potassium manganate (VII) solution into the unkown solution. If the purple acidified potassium manganate (VII) solution turns colourless / pale pink, the unknown is a reducing agent