Chemical Formulas Copy the text colored RED or Purple throughout the PPT. Also complete the TABLES

You have lists of:  Common polyatomic ions  Multivalent metals  Covalent prefixes Use your periodic table to determine the charges of common elements when they form ions Reminders from Naming Chemicals

Binary Ionic compounds

Definitions- Review Binary Ionic Compound- compound containing two elements—one metal and one non-metal + Cation + Cation - Anion - Anion Ionic Compound Ionic bond- bond formed by attraction between + and - ions

Metals & Non-Metals Ionic Bonds are between metals & non-metals HHe LiBeBCNOFNe NaMgAlSiPSClAr KCaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKr RbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXe CsBaLuHfTaWReOsIrPtAuHgTlPbBiPoAtRn FrRaLrRfDbSgBhHsMtUunUuuUubUut MetalsMetalloids Non- metals

These compounds:  End in “-ide” (except “hydroxide and cyanide”)  Do NOT contain covalent prefixes To write these formulas:  Write the symbol & charge of the first element (the metal, cation)  Write the symbol & charge of the second element (the non-metal, anion)  Add more of the cations and/or anions to have a neutral compound  Use subscripts to show how many of each type of ion is there. Identifying & Naming Binary Ionic

NameCationAnionCriss CrossFormula Sodium Chloride Calcium Bromide Cesium Chloride Aluminum Sulfide Potassium Oxide Calcium Sulfide Lithium NItride 2 1 Na +1 Cl -1 NoneNaCl Ca +2 Br -1 Ca +2 Br -1 CaBr 2

Example #1 Sodium chloride

Example #1 Sodium chloride Cation Anion Na +1 Cl -1 NaCl

Example #1 Sodium chloride Cation Anion Na +1 Cl -1 NaCl Na +1 Cl -1 The +1 and -1 cancel each other out The compound is neutral…no subscripts are needed.

Example #2 Calcium bromide

Example #2 Calcium bromide Cation Anion Ca +2 Br -1

Example #2 Calcium bromide Cation Anion Ca +2 Br -1 CaBr 2 Ca +2 Br -1 Criss Cross the charges down Ca +2 Br -1 The subscript “1” is dropped because its redundant. The subscript “2” is used to show that 2 anions are needed. Ca 1 Br 2 1 2

Example #3 Aluminum Sulfide

Example #3 Aluminum Sulfide Cation Anion Al +3 S -2

Example #2 Aluminum Sulfide Cation Anion Al +3 S -2 Al 2 S 3 Al +3 S -2 Criss Cross the charges down The subscript “2” is used to show that 2 cations are needed. The subscript “3” is used to show that 3 anions are needed. Al 2 S Al +3 S -2

Let’s Practice Example: Write the following chemical formulas Cesium chloride Potassium oxide Calcium sulfide Lithium nitride

Let’s Practice CsCl K2OK2O CaS Li 3 N Example: Write the following chemical formulas Cesium chloride Potassium oxide Calcium sulfide Lithium nitride

Polyatomic Ionic Compounds

Definition-Review Polyatomic Ion- more than one atom that together have a charge + Cation + Cation Polyatomic Ionic Compound- compound containing at least one polyatomic ion - Polyatomic Anion Polyatomic Ionic Compound

These compounds:  Do not end with “-ide” (except hydroxide & cyanide)  Do not use covalent prefixes To write these formulas:  Write the symbol & charge of the cation & anion  Add additional cations or anions to have a neutral compound  Use subscripts to show the number of ions When using subscripts with a polyatomic ion, you must put the polyatomic ion in parenthesis. Identifying & Naming Polyatomic Ionic

NameCationAnionCriss CrossFormula Sodium Carbonate Magnesium Nitrate Lithium Iodate Sodium Nitrate Calcium Chlorate Potassium Sulfite Calcium Hydroxide

Example #4 Sodium carbonate

Example #4 Sodium carbonate Cation Polyatomic Anion Na +1 CO 3 -2

Example #4 Sodium carbonate Cation Polyatomic Anion Na +1 CO 3 -2 Na 2 CO 3 Na + CO 3 2- Criss Cross the charges down Na + CO 3 2- The subscript “2” is used to show that 2 cations are needed. Na 2 CO 3 2 1

Example #5 Magnesium nitrate

Example #5 Magnesium nitrate Cation Polyatomic Anion Mg +2 NO 3 -1

Example #5 Magnesium nitrate Cation Polyatomic Anion Mg +2 NO 3 -1 Mg(NO 3 ) 2 Use parenthesis when adding subscripts to polyatomic ions Mg +2 NO 3 -1 Criss Cross the charges down Mg +2 NO 3 -1 The subscript “2” is used to show that 2 anions are needed. Mg(NO 3 ) 2 2 1

Let’s Practice Example: Write the following chemical formulas Lithium Iodate Sodium nitrate Calcium chlorate Potassium sulfite Calcium hydroxide

Let’s Practice LiIO 3 NaNO 3 Ca(ClO 3 ) 2 K 2 SO 3 Ca(OH) 2 Example: Write the following chemical formulas Lithium iodate Sodium nitrate Calcium chlorate Potassium sulfite Calcium hydroxide

Multivalent Metals

Definition-Review Multivalent Metal- metal that has more than one possibility for cationic charge

These compounds:  Will have roman numerals To write these formulas:  Same as binary ionic or polyatomic ionic.  The roman numerals tell the charge of the metal (cation) Identifying & Naming Multivalent Metals

NameCationAnionCriss CrossFormula Iron (III) Oxide Copper (II) Nitrate Iron (II) Nitrate Copper (I) Chloride Lead (IV) Hydroxide Tin (II) Oxide

Example #5 Iron (III) oxide

Example #5 Iron (III) oxide Cation Anion Fe +3 O -2

Example #6 Iron (III) oxide Cation Anion Fe +3 O -2 Fe 2 O 3 Fe +3 O 2- Criss cross the charges Fe +3 O 2- The subscript “2” and “3” are used to show the numbers of atoms needed. Fe 2 O 3 3 2

Example #7 Copper (II) nitrate

Example #7 Copper (II) nitrate Cation Polyatomic Anion Cu +2 NO 3 -1

Example #7 Copper (II) nitrate Cation Polyatomic Anion Cu +2 NO 3 -1 Cu(NO 3 ) 2 Cu +2 NO 3 -1 Criss cross the charges Cu +2 NO 3 -1 Use parenthesis when adding subscripts to a polyatomic ion Cu(NO 3 ) 2 1 2

Let’s Practice Example: Write the following chemical formulas Iron (II) nitrate Copper (I) chloride Lead (IV) hydroxide Tin (II) oxide

Let’s Practice Fe(NO 3 ) 2 CuCl Pb(OH) 4 SnO Example: Write the following chemical formulas Iron (II) nitrate Copper (I) chloride Lead (IV) hydroxide Tin (II) oxide

Binary Covalent Compounds

Definition-Review Binary Covalent Compound compound made from two non-metals that share electrons Non metal Non metal Non metal Non metal Covalent compound Covalent bond atoms share electrons

These compounds:  Use covalent prefixes To write these formulas:  Write the symbols of the first and second element  Use the covalent prefixes (assume the first element is “1” if there’s no prefix) as the subscripts to show number of atoms. Identifying & Naming Binary Covalent Atoms do not form charges when bonding covalently…you DO NOT need to worry about charges with this type!

NamePrefixFirst Element PrefixSecond Element Formula Dinitrogen Tetraoxide Di- = 2 Nitrogen = NTetra- = 4Oxide = ON2O4N2O4 Silicon dioxide Carbon monoxide Nitrogen dioxide Diphosphorus pentaoxide Carbon Tetrachloride

Example #7 Dinitrogen Tetraoxide

Example #7 Dinitrogen Tetraoxide N O “Di-” = 2 “Tetra-” = 4 N2O4N2O4

Example #8 Silicon dioxide

Example #8 Silicon dioxide Si O “Mono-” is not written for the first element “Di-” = 2 SiO 2

CAUTION!!! bi-di- Stands for “2” in covalent compounds Means there’s a hydrogen in the polyatomic anion “di” and “bi” do not mean the same thing! Carbon dioxide = CO 2 Sodium biphosphate = Na 2 HPO 4

Let’s Practice Example: Write the following chemical formulas Carbon monoxide Nitrogen dioxide Diphosphorus pentaoxide Carbon tetrachloride

Let’s Practice CO NO 2 P 2 O 5 CCl 4 Example: Write the following chemical formulas Carbon monoxide Nitrogen dioxide Diphosphorus pentaoxide Carbon tetrachloride

Nomenclature Summary Writing Chemical Formulas Does not contain covalent prefixes Ends with “-ide” (except hydroxide & cyanide) = Binary Ionic All others = Polyatomic Ionic Does contain covalent prefixes = Binary Covalent compound

Mixed Practice Example: Write the following chemical formulas Magnesium hydroxide Copper (II) nitrate Iron (III) oxide Nitrogen dioxide Sodium bicarbonate

Mixed Practice Mg(OH) 2 Cu(NO 3 ) 2 Fe 2 O 3 NO 2 NaHCO 3 Example: Write the following chemical formulas Magnesium hydroxide Copper (II) nitrate Iron (III) oxide Nitrogen dioxide Sodium bicarbonate