Forming Cations and Anions A metal has formed a positively charged ion (cation). Al → Al3+ + 3e- A nonmetal has formed a negatively charged ion (anion). N + 3e- → N3-

Naming Cations and Anions Name of cation is name of metal. Al3+ aluminum Name of anion is name of nonmetal slightly changed. N3- nitride

Simple Cations and Anions . Cation Name Anion H+ hydrogen H- hydride Li+ lithium O2- oxide Na+ sodium S2- sulfide Mg2+ magnesium F- fluoride Ca2+ calcium Cl- chloride Ag+ silver Br- bromide

Ionic Compounds (Main Group) . Formula Name NaCl sodium chloride Ca3N2 calcium nitride KBr potassium bromide BaO barium oxide AlN aluminum nitride

Formulas Using Main Group Elements calcium nitride Ca2+ N3- Ca3N2 cation always written first, anion second criss-cross superscripts but not signs! 3 2

Formulas for Binary Ionic Compounds . Name Formula sodium chloride NaCl calcium nitride Ca3N2 potassium bromide KBr barium oxide BaO aluminum nitride AlN

Rules for Formula Writing When the subscripts are 1, they are not written. When the subscripts are the same, they are not written. Signs (+/-) never appear with subscripts.

Cations of Transition Elements A transitional metal forming a positively charged ion (cation). Cu → Cu+ + e- Cu(I), cuprous Cu → Cu2+ + 2e- Cu(II), cupric Fe → Fe2+ + 2e- Fe(II), ferrous Fe → Fe3+ + 3e- Fe(III), ferric

Cations of Transition Elements Lower Valence Higher Valence chromium Cr2+, chromous Cr3+, chromic tin Sn2+, stannous Sn4+, stannic platinum Pt2+, platinous Pt4+, platinic mercury Hg22+, mercurous Hg2+, mercuric gold Au+, aurous Au3+, auric .

Binary Transition Ionic Compounds . Name Formula stannic chloride SnCl4 chromous nitride Cr3N2 auric bromide AuBr3 cupric oxide CuO cuprous oxide Cu2O

Binary Transition Ionic Compounds . Name Formula tin(IV) chloride SnCl4 cromium(II) nitride Cr3N2 gold(III) bromide AuBr3 copper(II) oxide CuO copper(I) oxide Cu2O

Ternary Compounds Ternary compounds are compounds made up of three elements. Many ternary compounds consists of a cation and a polyatomic ion. A polyatomic ion is a group of atoms covalently bonded that have a charge. All binary compounds end in –ide but not all compounds ending in –ide are binary!

Ternary Compounds Formula Name CaSO4 calcium sulfate Al(NO3)3 . Formula Name CaSO4 calcium sulfate Al(NO3)3 aluminum nitrate CuSO4 copper(II) sulfate Fe(IO3)3 iron(III) iodate

Ternary Compounds Name Formula sodium sulfate Na2SO4 mercuric nitrate . Name Formula sodium sulfate Na2SO4 mercuric nitrate Hg(NO3)2 stannic chromate Sn(CrO4)2 copper(II) phosphate Cu3(PO4)2

Oxides Oxides are compounds containing oxygen with an oxidation state (valence) of -2 (O2-). CO, CO2, SO2 Oxygen can also react with active metals to form peroxides (O22-) Na2O2 - sodium peroxide H2O2 - hydrogen peroxide

Hydrides Metallic hydrides are ionic compounds where hydrogen has an oxidation state of -1. The hydride ion, H-, is isoelectronic with He. Depending on the chemical environment, hydrogen can behave like a halogen (a highly electronegative element).

Hydrides Hydrogen has a greater attraction for an electron than an alkali or alkaline earth metal to form hydrides. NaH, LiH, CaH2 In ammonia, NH3, hydrogen has an oxidation number (valence) of +1 even though it is traditionally written is the nonmetal position.