4: Inorganic Nomenclature (Experiment)


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.

• 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

4: Inorganic Nomenclature (Experiment) is shared under a CC BY-NC license and was authored, remixed, and/or curated by Santa Monica College.