2. Binary Compounds Binary compounds contain only two elements. All binary compounds end in -ide. They are divided into two types, each of which has different rules for how to name them and write their formulas. IONIC = metal + nonmetal COVALENT = nonmetal + nonmetal

3. Ionic Compounds Metal + Nonmetal Ionic compounds are held together by the opposite charge of the metal (+) and the nonmetal (-). The SUM of the charges of all the atoms must equal ZERO.

4. Ionic Examples Na +1 and Cl -1 = Na +1 and O -2 = Ca +2 and O -2 = Al +3 and Cl -1 = Al +3 and O -2 = Al +3 and N -3 = NaCl sodium chloride Na 2 O sodium oxide CaO calcium oxide AlCl 3 aluminum chloride Al 2 O 3 aluminum oxide AlN aluminum nitride

5. Transition Metals Transition metals can have different charges in different compounds. So … the name of the compound includes a roman numeral that indicates the charge on the transition metal. EXAMPLES: iron (II) chloride: gold (I) sulfide: Fe +2 and Cl -1 = FeCl 2 Au +1 and S -2 = Au 2 S

6. Transition Metals - cont. When you name a compound with a transition metal you must determine the charge on the metal. Remember … the sum of the charges of all atoms must be zero. So use the charge on the nonmetal to figure out the charge on the transition metal. EXAMPLES: CuF Mn 2 O 3 SnO 2 Cu + (-1) =0 Cu=+1 copper (I) fluoride 2Mn + 3(-2) = 0 Mn=+3 manganese(III) oxide Sn + 2(-2) = 0 Sn=+4 tin (IV) oxide

7. Covalent Compounds Nonmetal + Nonmetal Covalent compounds are held together by shared pairs of electrons. No ions are involved. Naming covalent compounds involves using a prefix system that directly indicates the number of atoms of each element in one molecule of the compound.

8. Covalent Prefixes 1 = mono- 6 = hexa- 2 = di- 7 = hepta - 3 = tri- 8 = octa - 4 = tetra- 9 = nona- 5 = penta- 10 = deca- NOTE: Mono- is only used on the second element. In front of “oxide”, drop the “a” or “o” at the end of the prefix.

9. Covalent Examples CO CO 2 PCl 3 P 2 I 4 N 2 O S 2 F 10 AsI 2 B 4 C = carbon monoxide = carbon dioxide = phosphorus trichloride = diphosphorus tetraiodide = dinitrogen monoxide = disulfur decafluoride = arsenic diiodide = tetraboron monocarbide

11. Polyatomic Ions Polayatomic ions are ions made from more than one atom, and usually more than one element. There is a single charge for the entire ion. They are ions, and are named as ionic compounds are. Parentheses are used when more than one of a polyatomic ion is needed.

12. Examples of Polyatomic ions ammonium NH 4 +1 acetate C 2 H 3 O 2 -1 nitriteNO 2 -1 nitrateNO 3 -1 sulfateSO 4 -1 oxylateC 2 O 4 -2 phosphatePO 4 -3 hydroxideOH -1 cyanideCN -1 Most polyatomic ions end in “-ate” or “-ite”. This separates them from binary compounds that end in “-ide”. The positive polyatomic ion ammonium ends in “-ium”, like many metals. Beware hydroxide and cyanide, which break the normal rules and end in “- ide” but are polyatomic ions.

13. Polyatomic Ionic Examples sodium acetate = calcium nitrite = copper (II) phosphate = manganese (II) sulfate = aluminum cyanide = ammonium sulfide = Na +1 and C 2 H 3 O 2 -1 = NaC 2 H 3 O 2 Ca +2 and NO 2 -1 = Ca(NO 2 ) 2 Cu +2 and PO 4 -3 = Cu 3 (PO 4 ) 2 Mn +2 and SO 4 -2 = MnSO 4 Al +3 and CN -1 = Al(CN) 3 NH 4 +1 and S -2 = (NH 4 ) 2 S

14. Acids Aqueous acids have their own nomenclature, based on their negative ion. if ION ends in: then ACID is named: -ate -ic acid -ite -ous acid -ide hydro- & -ic acid

15. Acid Examples HCl= hydrogen chloride -> hydrochloric acid HNO 3 = hydrogen nitrate -> nitric acid HNO 2 = hydrogen nitrite -> nitrous acid H 2 PO 4 (aq) = HI (aq) = H 2 SO 3 (aq) = H 2 C 7 H 6 O 5 (aq)= HCN (aq) = phosphoric acid hydroiodic acid sulfurous acid citric acid hydrocyanic acid