Oxidation Numbers Flashcards
What are 3 oxidising agents?
NaClO (bleach), H2O2 (hydrogen peroxide), KMnO4
What is oxidation?
What is reduction?
The addition of oxygen to a substance/ The removal of oxygen from a substance
What is (a) oxidation (b) reduction in terms of electron transfer?
(a) oxidation is the the loss of electrons
(b) reduction is the gain of electrons
What is an (a) oxidising agent (b) reducing agent?
(a) A substance that brings about oxidation in another substance while it itself is reduced
(b) a substance that brings about reduction in another substance while it itself is oxidised
What is an oxidation number?
The charge that an atom has or appears to have when electrons are distributed according to a set of rules
What does (a) oxidation (b) reduction do to the oxidation number?
Oxidation increases the number
Reduction decreases the number
What is the rule about free elements?
The oxidation number is 0
What is the rule about the ox.no of a molecule?
The sum of all the ox.no. in a molecule is 0
What is the rule about a simple ion?
The ox.no. of a simple ion is a charge on that ion
What is the rule about a complex ion?
The sum of ox.no. in a complex ion is the charge on the ion
What is the rule about compounds containing H?
The ox.no. of H is 1… except in metal hydrides where it is -1
What is the rule about compounds containing oxygen?
The ox.no. of oxygen is -2 … except (a) in peroxides it’s -1 (b) when bonded to F it’s +2
What is the rule about alkaline metals?
They are always +1 in a compound
What is the rule about alkaline earth metals?
They are always +2 in compounds
What is the rule about halogens?
They are all -1 … except when bonded to a more electronegative element
