Chemistry
Common Polyatomic Ions.
CATIONS
1+
NH
H 3O 
ammonium
hydronium
2+

4
1
dime
ANIONS
1–
acetate
CH3COO

or C 2 H 3O2
chlorate
ClO 3
chlorite
bicarbonate or
hydrogen carbonate
hydrogen sulfate
ClO 2
hydroxide
OH 
hypochlorite
ClO 
nitrate
NO3
nitrite
NO2
perchlorate
ClO 4
permanganate
MnO4
1
2–
–
HCO3
3–
carbonate
CO32 
sulfate
SO42
SO32 
sulfite
thiosulfate
HSO4
only occurs in aqueous solutions
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phosphate
PO 43
Chemistry
1. The five most common polyatomic ions;
nitrate (NO3–)
carbonate (CO32–)
chlorate (ClO3–)
sulfate (SO42–)
phosphate (PO43–)
2. Derivatives.
–
Example, chlorate = ClO3
Note: Charges stay the same
–
a. .. Add 1 oxygen  per- -ate .................................. ClO4
perchlorate
–
b. .. ‘Base’
-ate ................................... ClO3
chlorate
c. .. Lose 1 oxygen
-ite ................................... ClO2
chlorite
d. .. Lose 2 oxygens hypo- -ite .................................. ClO
hypochlorite
–
–
–
3. N.B. Doesn’t always apply because some polyatomic ions don’t exist (e.g., NO4 )
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