Anions (negative ions)
Monoatomic
Oxyanions
(containing oxygen)
Others and
Exceptions
Oxyanions which
contain hydrogen
Rule:
Stem of the element
name + "ide"
Rule:
least oxygen
less oxygen
more oxygen
most oxygen
Rule:
These items do not follow any
rules; they must be memorized.
The rules referred to are those
in the box just to the left.
Rule:
H plus oxyanion:
"hydrogen" + name of
oxyanion
Examples:
H¯
hydride ion
F¯
fluoride ion
2
O ¯
oxide ion
3
N ¯
nitride ion
C 4¯
carbide ion
Examples:
ClO¯
ClO2¯
ClO3¯
ClO4¯
SO32¯
SO42¯
hypo ___ ite ion
___ ite ion
___ ate ion
per ___ ate ion
hypochlorite ion
chlorite ion
chlorate ion
perchlorate ion
sulfite ion
sulfate ion
Comment:
Halogens (except F) form all four
ions. When only two of the four
exist, they are the -ite and -ate ions.
Examples:
OH¯
CN¯
SCN¯
OCN¯
O22¯
O2¯
MnO42¯
MnO 4¯
C2H3O2¯
Cr2O72¯
C2O42¯
hydroxide ion
cyanide ion
thiocyanate ion
cyanate ion
peroxide ion
superoxide ion
manganate ion
permanganate ion
acetate ion
dicromate ion
oxalate ion
H2 plus oxyanion:
"dihydrogen" + name
of oxyanion
Examples:
HCO3¯
hydrogen
carbonate ion or
bicarbonate ion
HSO4¯
hydrogen
sulfate ion or bisulfate
ion
HPO42¯ hydrogen
phosphate ion or
biphosphate ion
H2PO4¯ dihydrogen
phosphate ion
Comment:
H2CO3 is not named using this
rule because it is a compound
see comment just to
and not an ion.
the left.