oxidation numbers Flashcards
(18 cards)
what is oxidation number based on?
a set of rules that apply to atoms
what is oxidation number a measure of
the number of electrons involved in bonding to a different element
what does the sum of oxidation numbers equal to
the overall charge of the species
when do we use oxidation numbers
when writing formulae and balancing electrons involved equations
in half equating, what is the total change in oxidation number equal to
the number of electrons involved
in redox reactions, what does the change in oxidation number for the oxidised species equal to
the change in oxidation number for the reduced species
what is the oxidation number of all pure elements
0
what is the oxidation number of group 1 elements
+1
what is the oxidation number of group 2 compounds
+2
what is the oxidation number of group 3 compounds
+3
what is always the oxidation number of fluorine
-1
what is the oxidation number of hydrogen usually
+1
when is hydrogens oxidation number not +1
when bonded to a metal (-1)
what is the oxidation number of oxygen usually
-2
when does oxygen not have a -2 oxidation state
when bonded to fluorine (+2)
when in peroxides (-1)
what is the oxidation state of chlorine usually
-1
what are the 3 steps for assigning oxidation numbers
- assign known oxidation numbers from the rules
- overall charge (sum of oxidation numbers)
- calculate oxidation number for the unknown atom
what do roman numerals represent
oxidation state of an element that can exist in one or more oxidation states
