Oxidation, reduction and redox equations Flashcards
What is oxidation and reduction in terms of:
- electrons
- oxidation number/state
Oxidation is loss of electrons, Reduction is gain of electrons (OIL RIG)
Oxidation is increase in oxidation number
Reduction is decrease in oxidation number
What are redox reactions?
When oxidation and reduction occur simultaneously in a reaction.
What is the oxidation state of an uncombined element?
0
What do oxidation states in a neutral compound add up to?
0
What is the oxidation state of hydrogen?
+1 apart from hydrides where it is -1 e.g NaH
What is the oxidation states of all halogens?
-1
What is the oxidation state of oxygen?
-2 apart from peroxides where it is -1 and +2 in OF2
What is the oxidation state of Aluminium?
+3
What is an oxidising agent?
Electron acceptor
What is the oxidation state of chlorine?
-1 but if in a compound with O or F then positive value
What is the oxidation state for fluorine?
always -1
What is a reducing agent?
Electron donator
In SO4 2- why is the oxidation state of sulphur 6 and not 8?
Because all the oxidation states must add up to the overall charge of the molecule.
O = 4 x -2 = -8
-8 + 6 = -2
hence sulphur must be 6.
What is the difference between reducing agents and oxidising agents?
Reducing agents lose electrons because they are oxidised themselves. Oxidising agents gain electrons because they are reduced themselves.
What is a hydride?
When hydrogen is bonded to a metal.
