List Of Polyatomic Ions That Must Be Memorized
ADVERTISEMENT
1Polyatomic Ions.table
List of Polyatomic Ions that
Must be Memorized for General Chemistry
+
Polyatomic Cation: NH
ammonium ion
4
Polyatomic Anions
-
-
Ionic Charge:
1
Ionic Charge:
2
Oxyanions:
Oxyanions:
Oxyanions that Contain
2–
CO
carbonate ion
–
ClO
perchlorate ion
Hydrogen:
3
4
–
–
ClO
chlorate ion
HCO
bicarbonate ion or
3
3
2–
SO
sulfate ion
–
ClO
chlorite ion
hydrogen carbonate ion
4
2
2–
SO
sulfite ion
–
3
ClO
hypochlorite ion
–
HSO
bisulfate ion or
4
2–
CrO
chromate ion
4
hydrogen sulfate ion
2–
Cr
O
dichromate ion
2
7
–
NO
nitrate ion
2–
3
C
O
oxalate ion
2
4
–
–
NO
nitrite ion
H
PO
dihydrogen
2–
S
O
thiosulfate ion
2
2
4
3
2
phosphate ion
Oxyanions that Contain
Others:
Hydrogen:
–
MnO
permanganate ion
4
–
2–
CN
cyanide ion
HPO
hydrogen
4
phosphate ion
–
OH
hydroxide ion
Others:
2–
O
peroxide ion
2
–
SCN
thiocyanate ion
-
Ionic Charge:
3
–
C
H
O
acetate ion
2
3
2
Oxyanion:
–
(Often written as CH
COO
)
3
3–
PO
phosphate ion
4
Some Notes and helpful hints:
Some textbooks refer to oxyanions as oxoanions. These are equivalent terms, meaning
•
simply a polyatomic anion that consists of a central atom bonded to one or more oxygen
atoms.
Oxyanions have names ending in –ate or –ite. The ending –ate is used for the most common
•
oxyanion. The ending –ite is used for an oxyanion that has the same charge, but one fewer
oxygen. The prefixes per- and hypo- are used for a series of four oxyanions of an element.
The prefix per- indicates one more oxygen than the oxyanion ending in –ate. The prefix hypo-
indicates one less oxygen than the oxyanion ending in –ite.
+
When hydrogen is added to an oxyanion, it is actually an H
that is added thus reducing the
•
negative charge of the parent anion by one for each hydrogen that is added. These are
named by adding hydrogen (for one hydrogen added) or dihydrogen (for two hydrogens
added) in front of the name of the parent anion. Some of these also have common names.
For example, hydrogen carbonate ion is also called bicarbonate ion.
Some polyatomic anions do not seem follow easy general rules regarding their names:
•
permanganate, chromate, dichromate, thiosulfate, oxalate, cyanide, hydroxide and acetate
are some examples.
Last Modified 12/31/08
Foothill College-General Chemistry, Dr. Larson
ADVERTISEMENT
0 votes
Related Articles
Related forms
Related Categories
Parent category: Education