Nomenclature I. Simple Ions (Ions that contain only one atom) I A. Negative Ions Negative ions have names ending in -IDE O = oxide ion, Cl = chloride ion, P = phosphide ion I B. Positive Ions 1. If there is only one possible positive oxidation state, the name of the ion is the same as the name of the element H +1 = hydrogen ion Na +1 = sodium ion Ba +2 = barium ion 2. If there are two positive oxidation states possible, the ion in the lower oxidation state has a name ending in -US and the ion in the higher oxidation state has a name ending in -IC Fe +2 = ferrous ion Sn +2 = stannous ion Cu +1 = cuprus ion Fe +3 = ferric ion Sn +4 = stannic ion Cu +2 = cupric ion II. Complex Ions (Ions that contain an atom in a positive oxidation state in combination with OXIDE IONS) II A. An atom in its highest positive oxidation state with enough oxide ions to give the combination a net negative charge, has a name ending in -ATE. B +3 + 2 O = BO 2 = borate Cr +6 + 4 O = CrO 4 = chromate Sn +4 + 3 O = SnO 3 = stannate II B. An atom in its second highest positive oxidation state with enough oxide ions to give the combination a net negative charge, has a name ending in -ITE. S +4 + 3 O = SO 3 = sulfite N +3 + 2 O = NO 2 = nitrite Pb +2 + 2 O = PbO 2 = plumbite 1
III. Exceptions III A. The phosphorous group (P & As not N or Sb or Bi) The complex ions of these two elements require one extra oxide ion. Phosphate = P +5 + 3 O = PO 3 + 1 O = PO 4 Arsenite = As +3 + 2 O = AsO 2 + 1 O = AsO 3 III B. The halogens (Cl, Br, I & At not F) These elements have four positive oxidation states and the names of the complex ions have the following pattern: Br +7 + 4 O = BrO 4 Br +5 + 3 O = BrO 3 Br +3 + 2 O = BrO 2 = per brom ate = perbromate ion (+7 oxidation state) = brom ate = bromate ion (+5 oxidation state) = brom ite = bromite ion (+3 oxidation state) Br +1 + 1 O = BrO = hypo brom ite = hypobromite ion (+1 oxidation state) Note: manganese is in Group VIIB while the halogens are Group VIIA. The +7 oxidation state of Mn follows the same name structure: Mn +7 + 4 O = MnO 4 = per mangan ate = permanganate ion III C. Miscellaneous Oxygen in the = O = oxide ion Oxygen in the = O 2 = peroxide ion Oxygen in the 1/2 = O 2 = superoxide ion Others to learn: OH = hydroxide ion CN = cyanide ion NH 4 +1 = ammonium ion Exotics: Fe +3 /Fe +2 = Ferric/Ferrous Cu +2 /Cu +1 = Cupric/Cuprus Replace one of the oxides with a sulfide and the prefix thio- is added: Carbonate ion = CO 3 thiocarbonate ion = CSO 2 A divalent complex ion combined with a hydrgen ion has the prefix bi- added Carbonate ion = CO 3 bicarbonate ion = HCO 3 Note: Compounds do NOT have charges, only ions have charges 2
6. Tl 2 TeO 3 = Thallius tellurite -- you figure out how to do it! Examples Write formulas for the following compounds: 1. Sodium Phosphate Sodium ion & Phosphate ion Na +1 & phosphorous in the highest positive oxidation state plus oxides P +5 + 3 O = PO 3 however P requires one extra O Thus, phosphate is PO 4 Combine in such a manner as to end up with no net charge (a compound) (3 sodium ions give a +3 to go with the of the phosphate) Na 3 PO 4 = sodium phosphate 2. Plumbus oxide Lead (plumbium) in the second highest positive oxidation state with O Pb +2 + O = PbO 3. Ammonium Carbonate Ammonium = NH +1 4 Carbonate = CO 3 & two ammoniums are required to balance the charge. Therefore (NH 4 ) 2 CO 3 = ammonium carbonate Name the following compounds 4. CaSiO 3 Calcium must be in the +2 oxidation state and has the name calcium ion. This leaves behind SiO 3. Knowing that each oxide is, the Si must be in the +4 oxidation state. Since this is the highest possible positive oxidation state, thus SiO 3 is called silicate. The compound is Calcium Silicate. 5. Fe 2 O 3 Assuming that oxygen is in the (oxide ions), the iron (ferrium) must be in the +3 oxidation state. Ferric Oxide. 3
WRITE FORMULAS FOR THE FOLLOWING: magnesium chromate aluminum oxide germanic phosphide sodium sulfite ammonium arsenate cupric selenate ferric iodite potassium superoxide stannus perchlorate strontium stannate hydrogen phosphite boron hydride NAME THE FOLLOWING NH 4 NO 2 KTlO 2 BaO 2 AgCl Hg 2 (NO 3 ) 2 RbClO 2 Zn(SbO 3 ) 2 InAsO 3 FeTeO 4 Ca(OH) 2 H 2 SO 4 KCN 4
ANSWERS TO THE PREVIOUS PAGE NAME FORMULA magnesium chromate........ MgCrO 4 aluminum oxide...... Al 2 O 3 germanic phosphide...... Ge 3 P 4 sodium sulfite...... Na 2 SO 3 ammonium arsenate......... (NH 4 ) 3 AsO 4 cupric selenate...... CuSeO 4 ferric iodite...... Fe(IO 2 ) 3 potassium superoxide....... KO 2 stannus perchlorate....... Sn(ClO 4 ) 2 strontium stannate...... SrSnO 3 hydrogen phosphite...... H 3 PO 3 boron hydride...... BH 3 FORMULA NAME NH 4 NO 2...... ammonium nitrite KTlO 2...... potassium thallate BaO 2...... barium peroxide AgCl... silver chloride Hg 2 (NO 3 ) 2...... mercurus nitrate RbClO 2... rubidium chlorite Zn(SbO 3 ) 2... zinc stibate InAsO 3... indiic arsenite FeTeO 4... ferrus tellurate Ca(OH) 2... calcium hydroxide H 2 SO 4... hydrogen sulfate KCN... potassium cyanide 5