NAMING IONIC COMPOUNDS There are a few general rules that apply when naming ionic compounds. 1. Most ionic compounds are also called salts. 2. Most ionic compounds exist as solids and many dissolve to form aqueous solutions. 3. An ionic compound is made up of a metal and a nonmetal; metals are located on the left side of the periodic table and nonmetals are on the right side. 4. The cation (positive ion) is written first followed by the anion (negative ion). 5. Before naming compounds, you should first memorize the individual cations and anions.

Nomenclature of binary ionic compounds Name the metal then the root of the nonmetal + ide ending: NaCl Sodium chloride BaCl2 Barium chloride H2S Hydrogen sulfide Mg3N2 Magnesium nitride NaF Sodium fluoride K2O Potassium oxide Notice that the cation is always mentioned first and then the anion. Notice that the anion always ends in -ide Notice that the number of elements in the compound is not mentioned in the name. Name the following ionic compounds: Na2O K2S MgBr2 AlN Ba3As2 CaCl2 AgCl AlH3 ZnI2 Li3P

Nomenclature of binary ionic compounds Answers: Na2O = sodium oxide K2S = potassium sulfide MgBr2 = magnesium bromide AlN = aluminum nitride Ba3As2 = barium arsenide CaCl2 = calcium chloride AgCl = silver chloride AlH3 = aluminum hydride ZnI2 = zinc iodide Li3P = lithium phosphide

Nomenclature of binary ionic compounds Some polyatomic anions that you must know: NO3- = nitrate NO2- = nitrite SO4 2 - = sulfate SO32- = sulfite PO43- = phosphate PO32- = phosphite CO32- = carbonate HCO31- = hydrogen carbonate or bicarbonate OH- = hydroxide CN- = cyanide C2H3O2- = acetate C2O42- = oxalate

Nomenclature of binary ionic compounds Naming salts composed of the polyatomic ions is the same as with the monatomic anions. Metal name then polyatomic name. NaOH sodium hydroxide Ba(NO3)2 barium nitrate H2SO4 hydrogen sulfate CsNO2 cesium nitrite Sometimes there is a common name: KHCO3 potassium hydrogen carbonate or potassium bicarbonate Note: the polyatomic anions must be memorized. Name the following ionic compounds: NaHCO3 K2SO3 MgSO4 KCN H2PO4 Ca(OH)2 NH4NO3 Zn(NO3)2 Li3PO4 HNO3

Nomenclature of binary ionic compounds Answers: NaHCO3 = sodium hydrogen carbonate or sodium bicarbonate K2SO3 = potassium sulfite MgSO4 = magnesium sulfate KCN = potassium cyanide H2PO4 = hydrogen phosphate Ca(OH)2 = calcium hydroxide NH4NO3 = ammonium nitrate Zn(NO3)2 = zinc nitrate Li3PO4 = lithium phosphate HNO3 = hydrogen nitrate

Nomenclature of binary ionic compounds The previous examples only named type 1 or “fixed oxidation state” cations. When naming type 2 or “variable oxidation state” cations the rules change. CuOH copper(I) hydroxide Fe(NO3)3 iron(III) nitrate CuSO4 copper(II) sulfate Sn(NO2)4 tin(IV) nitrite Sometimes a common name exists: CuOH cuprous hydroxide Fe(NO3)3 ferric nitrate When naming type 2 cations, the systematic method (IUPAC) requires the use of roman numerals after the elemental name to represent the oxidation state of the cation. The common name uses the –ic ending for the higher oxidation state and –ous ending for the lower oxidation state. Many times the old latin or greek name is used as the root. Name the following ionic compounds: CuHCO3 FeSO3 CuSO4 Cr(CN)3 Cr(PO4)2 Sn(OH)2 W(NO2)5 Ti(CO3)2 CoPO4 PbCl2

Nomenclature of binary ionic compounds Answers: CuHCO3 = copper(I) hydrogen carbonate or cuprous bicarbonate FeSO3 = iron(II) sulfite or ferrous sulfite CuSO4 = copper(II) sulfate or cupric sulfate Cr(CN)3 = chromium(III) cyanide Cr(PO4)2 = chromium (VI) phosphate Sn(OH)2 = tin(II) hydroxide or stannous hydroxide W(NO2)5 = tungsten(V) nitrite Ti(CO3)2 = titanium(IV) carbonate CoPO4 = cobalt(III) phosphate or cobaltic phosphate PbCl2 = lead(II) chloride or plumbous chloride

PRACTICE PROBLEMS # 9a 1. KBr 2. BaO 3. Na2O Below the formula, give the systematic name for the following compounds. If a common name exist, write it below the systematic name. 1. KBr 2. BaO 3. Na2O 4. BiF3 5. Cr2S3 6. Ti(NO3)4    potassium bromide Sodium oxide Barium oxide Bismuth (III) fluoride Titanium (IV) nitrate or titanic nitrate Chromium (III) sulfide The problem set continues on the next page.

GROUP STUDY PROBLEM # 9a 1. CaI2 2. Cs2S 3. Al2S3 Below the formula, give the systematic name for the following compounds. If a common name exist, write it below the systematic name. 1. CaI2 2. Cs2S 3. Al2S3 4. CdI2 5. SnCl2 6. Zn(NO3)2 7. Fe2O3 8. Fe(OH)2 9. PbSO4    The problem set continues on the next page.

Writing Chemical Formulas 1. The charge of the individual ions in a salt should add up to zero, the overall charge of the compound. For example NaCl is composed of Na+ ions and Cl- ions. For every one sodium ion you need one chloride ion (+1) + (-1) = 0 Ba2+ and N3- : You need 3 (+2 ) Barium ions to cancel out the 2 (-3) nitride ions so the overall charge of the compound is zero. 2. The individual ions should add up to the overall charge of the polyatomic ion. What is the charge of Mn in MnO4-? 1 Mn + 4 O = -1 so 1(Mn) + 4 (-2) = -1 so Mn - 8 = -1 so Mn = +7

PRACTICE PROBLEMS #9b LiCl Al2S3 CuO Ca(HCO3)2 FeCl3 KNO2 KClO4 Below the name, write the formula for the following compounds. Lithium chloride b) Aluminum sulfide e) Copper(II) oxide f)   Iron(III) chloride i) Calcium bicarbonate l Potassium nitrite Potassium perchlorate Ammonium carbonates s )Iron(II) phosphate w) Li + Cl - LiCl Al3+ S2- Al2S3 CuO Ca(HCO3)2 FeCl3 KNO2 KClO4 (NH4)2CO3 Fe3(PO4)2

GROUP STUDY PROBLEM #9b Below the name, write the formula for the following compounds. a) Barium oxide b) Sodium bromide   c) Copper(I) oxide d) Iron(II) chloride e) Potassium nitrite f) Calcium hydroxide g) Silver nitrate h) Ammonium chloride i) Lithium phosphate j) Sodium nitrite k) Sodium bicarbonate l) Calcium Carbonate m) Sodium sulfate n) Iron(III) hydroxide o) Copper(II) hypochlorite p) Sodium sulfite