Redox Flashcards
What is an oxidation number?
A measure of the number of electrons that an atom uses to bond with an atom of another element
How many rules is there?
10
What is rule 1?
Elements oxidation number = zero
What is rule 2?
Monoatomic ion oxidation number = charge of ion
Na+ = +1
What is rule 3?
Sum of oxidation numbers in neutral compound = zero
What is rule 4?
Sum of oxidation number in polyatomic ion = charge on ion
CO2 3- = -3
What is rule 5?
Oxidation numbers of compounds in:
Group 1 = +1
Group 2= +2
Group 3 = +3
What is rule 6?
Oxidation number of H normally is +1 but with a metal it is -1
What is rule 7?
F’s oxidation number = -1 in compounds
What is rule 8?
O’s oxidation number is normally -2 but in a peroxide it is
-1
And bonded with F it is +1
What is rule 9?
Transition metals’ oxidation number can vary
What is rule 10?
Cl, Br + I usually -1 except when in a compound with oxygen
What is the Roman numerals of SnO2?
Tin (IV) oxide
What is the Roman numerals of Mn(OH)2?
Manganese (II) hydroxide
What is oxidation?
Loss of electrons
What is reduction?
Gain of electrons
What is a disproportionation reaction?
The same element is oxidised and reduced at the same time
How can you tell if an element has been oxidised or reduced using oxidation states?
Oxidation number increases = oxidised
Oxidation number decreases = reduced
Which element is the reducing agent?
The one that has been oxidised
Which element is the oxidising agent?
The one that has been reduced
