Naming Inorganic Compounds Exam Questions With Correct Solutions

What is chemical nomenclature? - ANS The system used in naming substances. Organic Compounds - ANS Contain carbon, usually in combination with hydrogen, oxygen, nitrogen, or sulfur. Inorganic Compounds - ANS Anything that does not fall exclusively in the category of "organic compounds". Ionic Compounds - ANS Usually consist of metal ions combined with nonmetal ions. How to name Positive Ions (Cations) that are formed from metal atoms: - ANS Cations formed from metal atoms have the same name as the metal. Example: Na+ (sodium ion) Zn2+ (zinc ion) Al3+ (aluminum ion) How to name Positive Ions (Cations) that can form different cations: - ANS If a metal can form different cations, the positive charge is indicated by a Roman numeral in parentheses following the same of the metal. Example: Fe2+ (iron (II) ion) Fe3+ (iron (III) ion) Cu+ (copper (I) ion) Alternate way to name Cations that can form different cations (using Latin): - ANS The ending -ous or -ic represent the lower and higher charged ions. They are added to the root of the element's Latin name. Example: Fe2+ (ferrous ion) Fe3+ (ferric ion) Cu+ (cuprous ion) Cu2+ (cupric ion) How to name Cations formed from nonmetal atoms: - ANS Cations formed from nonmetal atoms have names that end in -ium. Example: NH4 (ammonium ion) H3O+ (hydronium ion) How to name Negative Ions (Anions) that are monatomic or polyatomic: - ANS The names of monatomic anions are formed by replacing the ending of the name of the element with -ide. Example: H- (hydride ion) O2- (oxide ion) N3- (nitride ion) Example: OH- (hydroxide ion) CN- (cyanide ion) O2- (peroxide ion) How to name Anions containing oxygen: - ANS Polyatomic anions containing oxygen have names ending in -ate or -ite. They are known as oxyanions. The ending -ate is used for the most common oxyanion of an element. The ending -ite is used for an oxyanion that has the same charge but one O atom fewer. Example: NO3- (nitrate ion) NO2- (nitrite ion) SO4 2- (sulfate ion) SO3 2- (sulfite ion) Prefixes for Polyatomic anions that contain oxygen: - ANS The prefix per- indicates one more O atom than teh oxyanion ending in -ate; the prefix hypo- indicates one O atom fewer then the oxyanion ending in -ite. Example: ClO4 - (perchlorate ion) ClO3 - (chlorate ion) CLO2 - (chlorite ion) ClO - (hypochlorite ion) How to name hydrogen and dihydrogens from anions - ANS Anions derived by adding H+ to an oxyanion are named by adding as a prefix the word hydrogen or dihydrogen. Example: CO3 2- (carbonate ion) HCO3 - (hydrogen carbonate ion) PO4 3- (phosphate ion) H2PO4 - (dihydrogen phosphate ion) How to name Ionic Compounds: - ANS Names of ionic compounds consist of the cation name followed by the anion name. Example: CaCl2 (calcium chloride) Al(NO3)3 (aluminum nitrate) Cu(ClO4)2 (copper (II) perchlorate) How to name Acids: - ANS Acids containing anions whose names end in -ide are named by changing the -ide ending to -ic, adding the prefix hydro- to this anion name, and then following with the word acid, as in the following examples: Anion: Cl- (chloride) Corresponding Acid: HCl (hydrochloric acid) Anion: S 2- (sulfide) Corresponding Acid: H2S (hydrosulfuric acid) How to name Acids (part 2): - ANS Acids containing anions whose names end in -ate or -ite are named by changing -ate to -ic, and -ite to -ous, then adding the word acid. Anion: ClO4 - (perchlorate) Corresponding Acid: HClO4 (perchloric acid) Anion: ClO3 - (chlorate) Corresponding Acid: HClO3 (chloric acid) Anion: ClO2 - (chlorite) Corresponding Acid: HClO2 (chlorous acid) Anion: ClO - (hypochlorite) Corresponding Acid: HClO (hypochlorous acid) How to Name Binary Molecular Compounds: - ANS 1. The name of the element farther to the left in the periodic table is usually written first. 2. If both elements are in the same group in the periodic table, the one having the higher atomic number is named first. 3. The name of the second element is given an -ide ending. 4. Greek prefixes are used to indicate the number of atoms of each element. Cl2O (dichlorine monoxide) N2O4 (dinitrogen tetroxide) NF3 (nitrogen trifluoride) P4S10 (tetraphosphorus decasulfide) Hydrocarbons - ANS Compounds that contain only carbon and hydrogen Alkanes - ANS The most basic class of hydrocarbons. Each carbon atom is bonded to four other atoms. the three simplest alkanes, which contain one (mathane, CH4), two (ethane, C2H6), and three (propane, C3H8) carbon atoms. Each alkane has a name that ends in -ane. For alkanes with five or more carbon atoms, the names are derived from prefixes used in naming binary compounds (mono-, di-, tri-...). For example, an alkane with eight carbon atoms is known as octane. Prefix Mono- - ANS 1