Names & Formulas of Ionic Compounds Ionic compounds are named using the names of the ions that compose them. To name an ionic compound: Cation name followed by anion name Learn the names and formulas of the ions in your syllabus. The following slides explain the systematic way that ions are named.

Naming Cations Cations formed from metal ions have the same name as the metal. K + potassium ion Ca 2+ calcium ion Al 3+ aluminum ion

Naming Cations Cations with varying charges the charge of the specific cation is given by Roman numeral in parentheses after the name of the metal Fe 2+ iron (II) ion Fe 3+ iron (III) ion Cu + copper (I) ion Cu 2+ copper (II) ion

Naming Cations One common polyatomic cation found in ionic compounds NH 4 + ammonium ion Note: Compounds whose formulas start with NH 4 are ionic even though they are composed only of non-metals.

Naming Anions Monoatomic anions drop the ending of the element’s name add “ide” NnitrogenOoxygen N 3 - O 2 - nitrideoxide

Naming Anions Some simple polyatomic anions use the “ide” ending as well OH - hydroxide CN - cyanide O 2 2- peroxide

Naming Oxyanions Oxyanions (polyatomic anions containing oxygen) have names ending in: “ate”most common oxyanion of the element “ite”same charge, 1 less oxygen NO 3 - nitrateSO 4 2- sulfate NO 2 - nitriteSO 3 2- sulfite CO 3 2- carbonatePO 4 3- phosphate PO 3 3- phosphite

Oxyanions (cont.) Some elements like the halogens can form more than two oxyanions: “per”1 more O than the “ate” oxyanion “hypo”1 less O than the “ite” oxyanion ClO 4 - perchlorate ClO 3 - chlorate ClO 2 - chlorite ClO - hypochlorite

Oxyanions Anions derived by adding H + to an oxyanion: add “hydrogen” or “dihydrogen” as prefix to oxyanion name CO 3 2- carbonate HCO 3 - hydrogen carbonate (usually called bicarbonate) PO 4 3- phosphate H 2 PO 4 - dihydrogen phosphate

Naming Ionic Compounds Name ionic compounds using cation name followed by anion name NaClsodium chloride CaBr 2 calcium bromide NaClOsodium hypochlorite Cu(NO 3 ) 2 copper (II) nitrate

Naming Ionic Compounds Example: Write the names of these ionic compounds. Na 2 O FeCl 3 (NH 4 ) 3 PO 4 KClO 4 SnO 2 Cu(NO 3 ) 2

Writing Formulas from Names Given the name of a compound, you must be able to write its formula. Identify the symbol and charge for each ion. Determine the correct number of each ion needed to balance the charges (write an electrically neutral formula).

Writing Formulas from Names Example: Write the empirical formula for ammonium sulfate (NH 4 ) 2 SO 4 ammonium sulfate NH 4 + SO 4 2- NH 4 +

Writing Formulas from Names Example: Write the formulas for these ionic compounds lithium chloride barium nitrate sodium perchlorate iron(III) oxide sodium hydrogen phosphate Lead (IV) sulfate

Names & Formulas of Acids Acid: a substance whose molecules form H + ions when dissolved in water HCl (aq) HCN (g) HClO 3 (aq) Name of acid depends on: Type of acid Oxygen present or not Pure or aqueous Name of anion

Names & Formulas of Acids Three naming systems for acids: Oxyanion-based acids (with oxygen) Acids with “ide” anions (no oxygen) aqueous solutions gases

Oxyanion Based Acids If the acid contains oxygen, identify the anion and write its name Change the ending of the anion name: “ite”  “ous acid” “ate”  “ic acid” HClO 4 perchlorate  perchloric acid HClO 2 chlorite  chlorous acid

Oxyanion Based Acids Naming acids derived from oxyanions of S and P: H 2 SO 4 : oxyanion = sulfate Sulfic acid Sulfuric acid H 3 PO 4 : oxyanion = phosphate Phosphic acid Phosphoric acid

Acids Without Oxyanions If the acid does not contain oxygen and is dissolved in water (aq): hydro + (anion name minus “ide”) + “ic acid” HCl (aq) hydro + chloride + ic acid hydrochloric acid “Hydro” = no oxygen and (aq)

Acids Without Oxyanions If the acid does not contain oxygen and is a gas (g): name the acid as an ionic compound: hydrogen followed by anion name HCl (g) hydrogen chloride “Hydrogen” = no oxygen and (g)

Naming Acids To name an acid: Does it have oxygen? Yes Write name of anion Change “ate” to “ic acid” Change “ite” to “ous acid” If no oxygen, is it (aq)? Yes Start with hydro Add the name of anion Change “ide” to “ic acid”

Naming Acids If no oxygen, is it (g)? Yes Start with hydrogen Add the name of the anion

Naming Acids Example: Name the following acids. HNO 3 HBr (aq) H 2 S (g)

Writing Formulas from Acid Names To write the formula of an acid starting with the name of the acid, first decide which category of acid it is: Oxyanion based No oxygen, (aq) (begins with “hydro”) No oxygen, (g)(begins with “hydrogen”) Write the formula for the anion (including charge). Add enough H + ions to make a neutral compound.

Writing Formulas from Acid Names Example: Write the formula for perchloric acid. Category: oxyanion containing acid Anion: perchloric acid  perchlorate (ClO 4 - ) Formula: HClO 4 ClO 4 - H+H+

Writing Formulas from Acid Names Example: Write the formula for each of the following acids. Phosphoric acid: Hydrobromic acid: Hydrogen cyanide:

Naming Acids You must know the names and formulas for the following acids: HF (aq)hydrofluoric acid HCl (aq)hydrochloric acid HBr (aq)hydrobromic acid HI (aq)hydroiodic acid HClO 4 perchloric acid HClO 3 chloric acid H 2 SO 4 sulfuric acid HNO 3 nitric acid

Naming Acids You must know the names and formulas for the following acids: H 3 PO 4 phosphoric acid HC 2 H 3 O 2 acetic acid H 2 CO 3 carbonic acid H 2 S (g)hydrogen sulfide HCN (g)hydrogen cyanide

Binary Molecular Compounds Binary molecular compound: compound composed of molecules with two different types of atoms Remember: Many molecular compounds are composed strictly of non-metals. SO 2 N 2 O 4 H 2 OPCl 5 P 4 O 10 CO

Binary Molecular Compounds The names of binary molecular compounds give both the type and number of each type of atom present. The general pattern for naming binary molecular compounds is: prefix element name prefix element name with ide ending

Binary Molecular Compounds The first element is named using the name of the element. The second element is named using the “ide” ending. Greek prefixes are used to indicate the number of each type of element present. prefix element name prefix element name with ide ending

Greek Prefixes PrefixMeaning mono1 di2 tri3 tetra4 penta5 hexa6 hepta7 octa8 nona9 deca10 You must know these!! P 4 S 10 = tetraphosphorus decasulfide

Binary Molecular Compounds Special conventions for using Greek prefixes: Mono is never used with the first element The “a” or “o” in the prefix is dropped if the name of the element begins with a vowel. CO: carbon monooxide carbon monoxide

Binary Molecular Compounds Example: Name the following compounds. N 2 O 4 PCl 5 Cl 2 O 7

Binary Molecular Compounds Example: Write the formulas for the following compounds. tetraphosphorus decoxide sulfur trioxide disulfur dichloride

Naming — Revisited Before you can correctly name a compound or write its formula, YOU MUST determine which type of compound it is: Ionicstarts with a metal or NH 4 Acidstarts with H or H n Binary Moleculartwo non-metals THEN use the appropriate naming system or method to write the formula.

Simple Organic Compounds Organic compounds: compounds that contain carbon and hydrogen, often in combination with oxygen or nitrogen.

Simple Organic Compounds You must know the names and structural formulas of the following simple organic compounds: Methane Propane Methanol Ethanol Acetic acid Acetone

Simple Organic Compounds Methane: Ethane: Methanol: Ethanol:

Simple Organic Compounds Propane: Acetic Acid: Acetone:

Common “Household” Chemicals You are responsible for knowing the names and formulas for the chemical present in: Water (H 2 O) Ammonia (NH 3 ) Baking soda sodium bicarbonate NaHCO 3 Natural gas Methane CH 4 Vinegar Acetic acid HC 2 H 3 O 2 (structure on previous slide)

Common “Household” Chemicals You are responsible for knowing the names and formulas for the chemical present in: Table salt Sodium chloride NaCl Bleach Sodium hypochlorite NaClO Hydrogen peroxide H 2 O 2

Common “Household” Chemicals You are responsible for knowing the names and formulas for the chemical present in: Drinking alcohol Ethanol C 2 H 5 OH Rubbing alcohol Isopropyl alcohol Nail polish remover Acetone