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Common Polyatomic Ions and Acids
A polyatomic ion or molecular ion is a group of atoms all connected with covalent bonds that collectively have a positive or negative charge. It will be useful to know the names, formulas, and charges of the following polyatomic ions.
Cations: positively charged ions
Anions: negatively charged ions
CO32- | carbonate |
HCO3- | hydrogen carbonate or bicarbonate |
C2H3O2- | acetate |
CH3COO- | acetate |
CN- | cyanide |
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NO2- | nitrite |
NO3- | nitrate |
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O22- | peroxide |
O2- | superoxide |
OH- | hydroxide |
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SiO44- | silicate |
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PO33- | phosphite |
PO43- | phosphate |
HPO42- | hydrogen phosphate |
H2PO4- | dihydrogen phosphate |
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SO32- | sulfite |
SO42- | sulfate |
HSO3- | hydrogen sulfite or bisulfite |
HSO4- | hydrogen sulfate or bisulfate |
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ClO- | hypochlorite (the active ingredient in bleach) |
ClO2- | chlorite |
ClO3- | chlorate |
ClO4- | perchlorate |
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MnO4- | permanganate |
CrO42- | chromate |
Cr2O72- | dichromate |
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