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4: Inorganic Nomenclature (Experiment)

  • Page ID
    95876
  • Objectives

    • To practice naming and writing chemical formulas for many inorganic compounds, both ionic and molecular.

    In this exercise you will practice naming and writing chemical formulas for many inorganic compounds, both ionic and molecular. Before beginning the exercise you should carefully read all the sections of your text (or notes) on the names and formulas of ionic compounds, simple covalent compounds, and acids. The following is a brief summary of the Nomenclature rules for each of these types of compounds.

    Ionic Compounds

    Ionic compounds are composed of metal cations and non-metal anions, or, of polyatomic ions.

    • Names and formulas always start with the positively charged cation.
    • Ions are combined in ratios so that the final ionic compound is neutral.
    • Never use prefixes in the names of ionic compounds. The cation name is simply combined with the anion name only.
    • If the cation is capable of having more than one possible charge, the cation charge is included in the name as a Roman numeral in brackets (Stock system).

    Several ion names, charges and formulas are provided in the following tables. They must be memorized as soon as possible.

    Names of Selected Cations (names are in alphabetical order)

    \(\ce{Al^{3+}}\) Aluminum \(\ce{Pb^{2+}}\) Lead(II); Plumbous
    \(\ce{NH4^{+}}\) Ammonium \(\ce{Pb^{4+}}\) Lead(IV); Plumbic
    \(\ce{As^{3+}}\) Arsenic(III) \(\ce{Li^{+}}\) Lithium
    \(\ce{Ba^{2+}}\) Barium \(\ce{Mg^{2+}}\) Magnesium
    \(\ce{Cd^{2+}}\) Cadmium \(\ce{Mn^{2+}}\) Manganese(II)
    \(\ce{Ca^{2+}}\) Calcium \(\ce{Mn^{4+}}\) Manganese(IV)
    \(\ce{Cr^{2+}}\) Chromium(II) \(\ce{Hg2^{2+}}\) Mercury(I); Mercurous
    \(\ce{Cr^{3+}}\) Chromium(III) \(\ce{Hg^{2+}}\) Mercury(II); Mercuric
    \(\ce{Cr^{6+}}\) Chromium(VI) \(\ce{Ni^{2+}}\) Nickel(II); Nickelous
    \(\ce{Co^{2+}}\) Cobalt(II); Cobaltous \(\ce{K^{+}}\) Potassium
    \(\ce{Co^{3+}}\) Cobalt(III); Cobaltic \(\ce{Ag^{+}}\) Silver
    \(\ce{Cu^{+}}\) Copper(I); Cuprous \(\ce{Na^{+}}\) Sodium
    \(\ce{Cu^{2+}}\) Copper(II); Cupric \(\ce{Rb^{+}}\) Rubidium
    \(\ce{Au^{3+}}\) Gold(III); Auric \(\ce{Sr^{2+}}\) Strontium
    \(\ce{H^{+}}\) Hydrogen \(\ce{Sn^{2+}}\) Tin(II); Stannous
    \(\ce{Fe^{2+}}\) Iron(II); Ferrous \(\ce{Sn^{4+}}\) Tin(IV); Stannic
    \(\ce{Fe^{3+}}\) Iron(III); Ferric \(\ce{Zn^{2+}}\) Zinc

    Names of Selected Anions (names are in alphabetical order, but with oxyanions grouped together)

    \(\ce{C2H3O2^{-}}\) Acetate \(\ce{I^{-}}\) Iodide
    \(\ce{AsO4^{3-}}\) Arsenate \(\ce{IO4^{-}}\) Periodate
    \(\ce{BO3^{3-}}\) Borate \(\ce{MoO4^{2-}}\) Molybdate
    \(\ce{B4O7^{2-}}\) Tetraborate \(\ce{N^{3-}}\) Nitride
    \(\ce{Br^{-}}\) Bromide \(\ce{NO2^{-}}\) Nitrite
    \(\ce{BrO^{-}}\) Hypobromite \(\ce{NO3^{-}}\) Nitrate
    \(\ce{BrO3^{-}}\) Bromate \(\ce{C2O4^{2-}}\) Oxalate
    \(\ce{CO3^{2-}}\) Carbonate \(\ce{O^{2-}}\) Oxide
    \(\ce{HCO3^{-}}\) Bicarbonate; Hydrogen carbonate \(\ce{O2^{2-}}\) Peroxide
    \(\ce{Cl^{-}}\) Chloride \(\ce{MnO4^{-}}\) Permanganate
    \(\ce{ClO^{-}}\) Hypochlorite \(\ce{P^{3-}}\) Phosphide
    \(\ce{ClO2^{-}}\) Chlorite \(\ce{PO4^{3-}}\) Phosphate
    \(\ce{ClO3^{-}}\) Chlorate \(\ce{HPO4^{2-}}\) Hydrogen phosphate
    \(\ce{ClO4^{-}}\) Perchlorate \(\ce{H2PO4^{-}}\) Dihydrogen phosphate
    \(\ce{CrO4^{2-}}\) Chromate \(\ce{Se^{2-}}\) Selenide
    \(\ce{Cr2O7^{2-}}\) Dichromate \(\ce{S^{2-}}\) Sulfide
    \(\ce{C6H5O7^{3-}}\) Citrate \(\ce{SO3^{2-}}\) Sulfite
    \(\ce{CN^{-}}\) Cyanide \(\ce{SO4^{2-}}\) Sulfate
    \(\ce{F^{-}}\) Fluoride \(\ce{HSO3^{-}}\) Bisulfite; Hydrogen sulfite
    \(\ce{H^{-}}\) Hydride \(\ce{HSO4^{-}}\) Bisulfate; Hydrogen sulfate
    \(\ce{OH^{-}}\) Hydroxide \(\ce{S2O3^{2-}}\) Thiosulfate
    \(\ce{SCN^{-}}\) Thiocyanate

    Examples

    • \(\ce{K2S}\)

    2 \(\ce{K^{1+}}\) cations and 1 \(\ce{S^{2-}}\) anion

    potassium sulfide

    • \(\ce{FeCl3}\)

    1 \(\ce{Fe^{3+}}\) cation and 3 \(\ce{Cl^{1-}}\) anions

    iron(III) chloride, or ferric chloride

    • \(\ce{Mg3(PO4)2}\)

    3 \(\ce{Mg^{2+}}\) cations and 2 \(\ce{PO4^{3-}}\) anions

    magnesium phosphate

    Simple Covalent (Molecular) Compounds

    Simple covalent (molecular) compounds are composed of non-metal atoms only.

    • The more metallic non-metal is written first.
    • Prefixes are used in the name to indicate the number of each atom present. A list of prefixes 1-10 (and 12) is provided below, which must be memorized.
    • The prefix “mono” is dropped if there is only one of the first element.
    • The name of the second element always ends in "-ide."

    Prefixes for Covalent Compounds

    1

    Mono

    2

    Di

    3

    Tri

    4

    Tetra

    5

    Penta

    6

    Hexa

    7

    Hepta

    8

    Octa

    9

    Nona

    10

    Deca

    12

    Dodeca

    Examples

    • \(\ce{P4S3}\)

    4 \(\ce{P}\) atoms and 3 \(\ce{S}\) atoms

    tetraphosphorus trisulfide

    • \(\ce{N2O}\)

    2 \(\ce{N}\) atoms and 1 \(\ce{O}\) atom

    dinitrogen monoxide

    • \(\ce{BrCl5}\)

    1 \(\ce{Br}\) atom and 5 \(\ce{Cl}\) atoms

    bromine pentachloride

    Acids

    Acids are composed of hydrogen cations and non-metal anions or polyatomic anions.

    • H always leads the formula.
    • Acids are in the aqueous state.
    • Ions are combined in ratios so that the final acid is neutral.
    • The acid name depends on the name of the anion involved:

    \[ \ce{H^{1+}} + \text{Anion} \ce{->} \text{Acid}\]

    \[ \ce{H^{+}} + \text{___ide} \ce{->} \text{Hydro___ic Acid}\]

    \[ \ce{H^{+}} + \text{___ate} \ce{->} \text{___ic Acid}\]

    \[ \ce{H^{+}} + \text{___ite} \ce{->} \text{___ous Acid}\]

    Examples

    • \(\ce{HBr}\) (aq)

    1 \(\ce{H^{1+}}\) cation and 1 \(\ce{Br^{1-}}\) anion (bromide)

    hydrobromic acid

    • \(\ce{HNO3}\) (aq)

    1 \(\ce{H^{1+}}\) cation and 1 \(\ce{NO3^{1-}}\) anion (nitrate)

    nitric acid

    • \(\ce{H2SO3}\) (aq)

    2 \(\ce{H^{1+}}\) cations and 1 \(\ce{SO3^{2-}}\) anion (sulfite)

    sulfurous acid

    Hydrates

    Hydrates are solid substances that also contain water molecules in their crystal structure.

    • The number of water molecules for each formula unit is fixed.
    • The formula is written the same as any other compound, but then we add a dot (\(\ce{*}\)), (note that this is NOT a multiplication sign!) followed by the number of water molecules per ionic formula unit and the symbol \(\ce{H2O}\).
    • The name is the same as for any other compound, but we add the word “hydrate” at the end with a Latin prefix to indicate the number of water molecules per ionic formula unit.

    Examples

    • \(\ce{CuSO4*5H2O}\)

    1 \(\ce{Cu^{2+}}\) ion, 1 \(\ce{SO4^{2-}}\) ion, and 5 water molecules

    Copper (II) sulfate pentahydrat

    • sodium carbonate decahydrate

    \(\ce{Na^{+}}\) ion(s), \(\ce{CO3^{2-}}\) ions(s), and 10 water molecules

    \(\ce{Na2CO3*10H2O}\)

    Lab Report: Inorganic Nomenclature

    Part A: Naming Practice

    Name each of the compounds in the following table. Compounds marked with a star (*) should be named using both the Stock and the “ic/ous” naming systems.

    1

    *\(\ce{Au(NO3)3}\)

    2

    \(\ce{Ca3(PO4)2}\)

    3

    \(\ce{Cl2O}\)

    4

    \(\ce{LiH}\)

    5

    \(\ce{NaClO3}\)

    6

    \(\ce{H2C2O4}\) (aq)

    7

    \(\ce{AlCl3}\)

    8

    \(\ce{Ni(CN)2}\)

    9

    \(\ce{P4O10}\)

    10

    *\(\ce{SnSO3}\)

    11

    \(\ce{(NH4)2CO3}\)

    12

    \(\ce{HF}\) (aq)

    13

    \(\ce{CrO3}\)

    14

    \(\ce{Ba(C2H3O2)2}\)

    15

    \(\ce{ICl5}\)

    16

    \(\ce{Fe(NH4)2(SO4)2*6H2O}\)

    17

    *\(\ce{PbS2}\)

    18

    \(\ce{HBrO}\) (aq)

    19

    \(\ce{ZnCr2O7}\)

    20

    \(\ce{Na2S2O3*5H2O}\)

    Part B: Formula Practice

    Write the formulas for each of the compounds in the following table.

    1

    Ferric sulfate

    2

    Strontium oxalate

    3

    Chromic acid

    4

    Nickel(III) carbonate

    5

    Silver bromate

    6

    Dinitrogen difluoride

    7

    Magnesium molybdate

    8

    Sodium hydrogen phosphate

    9

    Hydrocyanic acid

    10

    Cuprous nitrite

    11

    Nickelous nitrate hexahydrate

    12

    Manganese(II) periodate

    13

    Sulfur trioxide

    14

    Mercury(I) iodide

    15

    Lithium thiosulfate

    16

    Chlorous acid

    17

    Plumbic bicarbonate

    18

    Barium chloride dihydrate

    19

    Aluminum chromate

    20

    Rubidium peroxide

    Part C: Formulas and Names

    If the name of the compound is given, write its formula. If the formula is given, write its name. You may use either the Stock system or “ic/ous” system for naming, where relevant.

    1 \(\ce{Ca(ClO2)2}\)
    2 Stannic fluoride
    3 Silicon tetrabromide
    4 \(\ce{Cr(BrO)2}\)
    5 Potassium tetraborate tetrahydrate
    6 Gallium arsenate
    7 \(\ce{HNO2}\) (aq)
    8 \(\ce{LiH2PO4}\)
    9 Magnesium tetraborate
    10 \(\ce{Br3O8}\)
    11 \(\ce{MnO2}\)
    12 Silver thiocyanate
    13 Citric acid
    14 \(\ce{AlN}\)
    15 \(\ce{Cu(NO3)2*3H2O}\)
    16 Titanium(II) bisulfate
    17 Sulfur hexafluoride
    18 \(\ce{(NH4)3PO4}\)
    19 Cuprous hydroxide
    20 \(\ce{HClO4}\) (aq)
    21 Plumbous oxalate
    22 \(\ce{NO2}\)
    23 \(\ce{CdCO3}\)
    24 Bismuth(V) oxide
    25 Permanganic acid
    26 \(\ce{Ag2SO4}\)
    27 Strontium phosphide
    28 Tricarbon disulfide
    29 \(\ce{Au2O3}\)
    30 Sodium dichromate
    31 \(\ce{HI}\) (aq)
    32 \(\ce{NH4HSO3}\)
    33 Mercuric cyanide
    34 \(\ce{Cl2O7}\)
    35 Vanadium(III) nitrate
    36 Sulfurous acid
    37 \(\ce{KF}\)
    38 Zinc hypochlorite
    39 \(\ce{CO}\)
    40 Nickelous acetate