Taylor’s Polyatomic Ion Charge Rule:

1	IA	IIA			H		IIIa	IVA	VA	VIA	VIIA	He
2							3-	2-**	1-^#			Ne
3								2-**	3-	2-	1-	Ar
4			3-	2-	2-*	2-			3-	2-	1-	Kr
5				2-				2-**	3-	2-	1-	Xe
6				2-				2-**				Rn
7
				Link to Interactive Nonmetal Oxyanions
			Link to Interactive Transitional Metal Polyatomic Ions

*In Permanganate the Per means more charge (add +1 to manganate’s charge), not more oxygen as in perchlorate. Therefore: Permanganate MnO₄^1-

^{** Group IVA oxyanions have 2- charges instead of the expected 4- ! Why?}

^{# Nitrate has a 1- charge instead of the expected 3- ! Why?}

Observe the charges on the polyatomic ions below:

Use the position of the oxyanion on the periodic chart to determine the charge on the –ate Polyatomic Ion. See above!

Observation:

Seven of the Nonmetal oxyanions have the same charge as the charge on the central nonmetals –ide ionic charge.

Why?

Compare each to its corresponding –ide charge:

Observation:

Carbonate, Nitrate, and Silicate have oxyanionic charges that are different from what you would expect if you used the Roman Numeral A Group notation to determine the oxyanion’s charge. Why?

Exactly how do the charges compare to what you would expect?

Borate is also different because the Boron in Borate does not follow the octet rule. It follows the rules of six so the charge is 3- instead of 5-.

Footnote: *The Single and Double Bond Rules apply to using the simple octet rule to all the nonmetal oxyanions. All nonmetals, except hydrogen, have only 8 total electrons. (hydrogen 2) If you apply the concept of formal charge, oxidation number, and total valence electrons, the central nonmetal may have ten and twelve electrons utilizing vacant d-orbitals and may add additional double bonds in the dot structures of oxyanions in periods three, four, and five. See below.

Review the following web site for a discussion of dot structures of polyatomic ions with additional double bonds:

http://www.homework-help-secrets.com/polyatomic-ions.html

4. All –ate Transitional Metal Polyatomic Ions have a charge of 2-, except Vanadate which is 3-.

Below is a complete listing of polyatomic ions from the CRC Handbook of Chemistry and Physics:

Acetate CH3COO^− or C2H3O2^− Aluminate AlO2^− or Al2O4^2− Amide NH2^− Ammonium NH4^+ Antimonate SbO4^3− Antimonite SbO3^3− Arsenate AsO4^3− Arsenite AsO3^3− Azide N3^− Benzoate C6H5COO^− Bicarbonate HCO3^− Borate BO3^3− Metaborate BO2^− Tetraborate B4O7^2− Bromate BrO3^− Bromite BrO2^− Carbide C2^2− Carbonate CO3^2− Carbonite CO2^2− Chlorate ClO3^− Chlorite ClO2^− Chromate CrO4^2− Chromite CrO2^− Chromyl CrO2^2+ Citrate C6H5O7^3− Cyanate OCN^− Cyanide CN^− Dichromate Cr2O7^2− Dihydrogen Arsenate H2AsO4^− Dihydrogen Phophate H2PO4^− Dihydrogen Phosphite H2PO3^− Dioxygenyl O2^+ Disulfide S2^2− Ferrate FeO4^2−

Ferricyanide Fe(CN)6^3− Ferrocycanide Fe(CN)6^4− Formate (formiate) HCO2^− Fulminate CNO^− Hydrazide N2H3^− Hydrogen carbonate HCO3^− Hydrogen arsenate HAsO4^2− Hydrogen phosphate HPO4^2− Hydrogen phosphite HPO3^2− Hydrogen sulfate HSO4^− Hydrogen sulfite HSO3^− Hydrogen telluride HTe^− Hydronium H3O^+ Hydroxide OH^− Hypobromite BrO^− Hypochlorite ClO^− Hypoiodite IO^− Hypophosphite PO2^3− Hyposulfite SO2^2− Periodate IO4^− Iodate IO3^− Thiodide I3^− Iodite IO2^− Isocyanate NCO^− Mercury (I) Hg2^2+ Manganate MnO4^2− Molybdate MoO4^2− Nitrate NO3^− Nitrite NO2^− Oxalate C2O4^2− Ozonide O3^− Perbromate BrO4^− Perchlorate ClO4^− Permanganate MnO4^− Peroxide O2^2− Perrhenate ReO4^− Peroxomonosulfate SO5^2− Peroxodisulfate S2O8^2−

Pertechnetate TcO4^− Phosphate PO4^3− Phosphite PO3^3− Plumbate PbO3^2− Plumbite PbO2^2− Pyridinium C5H6N^+ Pyrophosphate P2O7^4− Pyrylium C5H5O^+ Quartenary Ammonium NR4^+ Selenate SeO4^2− Selenite SeO3^2− Silicate SiO3^2− Disilicate Si2O5^2− Metasilicate SiO3^2− Orthosilicate SiO4^4− Pyrosilicate Si2O7^6− Stannate SnO3^2− Stannite SnO2^2− Sulfate SO4^2− Sulfite SO3^2− Sulfonium R3S^+ Superoxide O2^− Tartrate (CH(OH)COO)2^2− Metatellurate TeO4^2− Orthotellurite TeO6^6− Tellurite TeO3^2− Thiocyanate SCN^− Thiosulfate S2O3^2− Tosylate CH3C6H4SO3^− (toluenesulfonate) Triflate CF3SO3^− (trifluoromethanesulfonate) Tungstate WO4^2− Uranyl UO2^2+ Vanadate VO4^3− Vanadyl VO^2+ Pervanadyl VO2^+