Chemical Nomenclature

Written by Y. Deng, J. Bazzi and D. BandyopadhyayProduced by the Science Learning Center (SLC)

University of Michigan -Dearborn

2013

What is Chemical Nomenclature?

A set of rules to generate systematic names for chemical substancesLanguage of chemistryUsed by scientists, particularly chemists, to communicate and discuss the issues related to chemistry

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Purpose

To introduce the systems of chemical nomenclature used to name inorganic compounds and to write chemical formulas of inorganic compounds.

Inorganic vs. Organic CompoundsInorganic compounds are referred traditionally to those

extracted from non-living things (e.g., rocks) and viewed as being synthesized by geological systems.Examples: calcium carbonate (a major compound found in rocks): CaCO3

Sodium chloride (a major compound found in table salt): NaClOrganic compounds, on the other hand, are referred

traditionally to those found in living things (e.g., plants and animals) and mainly contain carbon-hydrogen chain and ring structures. Examples: Ethanol (one of the fermentation products of grapes): CH3CH2OH

Caffeine (one of the components found in coffee beans):

Specific Objectives:1. Write correct chemical formulas

for inorganic compounds.

2. Name inorganic compounds.

3. Determine the electric charges of ions involved in ionic compounds.

THE PERIODIC TABLE OF ELEMENTS AND SYMBOLS OF THE ELEMENTS

Part I

The Periodic Table of the Elements is a tabular arrangement of the chemical elements, organized on the basis of their atomic numbers (i.e., the number of protons in their nuclei) and recurring chemical properties.

There are 118 elements currently listed on the periodic table. About 90 elements are found in nature. The remaining ones have been produced artificially using high energy particle accelerators.

Each element has its name and symbol. The symbol can be up to three letters. The first letter must be capitalized and the second and third, if any, are in a lower case.

Examples:Name SymbolNitrogen NChlorine ClUnun pentium Uup

The symbols of the elements are derived from:

English nameshydrogen – Hcalcium– Caphosphorus – P

Latin namesFerrum (iron) – FeAurum (gold) – Au

Chemical Symbols Derived from Their English Names

Symbol English Name Symbol English Name

H hydrogen S sulfur

C carbon Cl chlorine

N nitrogen Ca calcium

O oxygen Mg magnesium

F fluorine Mn manganese

Al aluminum Co cobalt

Si silicon Ni nickel

P phosphorous Zn zinc

Ba barium Cr chromium

Chemical Symbols Derived from Their Latin NamesSymbol English

NameLatin Name

Meaning

Ag silver argentum silver

Au gold aurum shining dawn

Fe iron ferrum iron

Hg mercury hydrargyrum liquid silver

K potassium kalium potash silver

Na sodium natrium soda

Pb lead plumbum heavy

Cu copper cuprum “from Cyprus” where the Romans found copper.

alkali metals

Noble gases

1IA alkaline

earth metals halogens

18VIIIA

or 0

HHydrogen

2IIA

13IIIA

14IVA

15VA

16VIA

17VIIA

HeHelium

LiLithium

BeBeryllium

Transition Metals

BBoron

CCarbon

NNitrogen

OOxygen

FFluorine

NeNeon

NaSodium

MgMagnesium

AlAluminum

SiSilicon

PPhosphorus

SSulfur

ClChlorine

ArArgon

KPotassium

CaCalcium

BrBromine

RbRubidium

SrStrontium

SnTin

IIodine

XeXenon

CsCesium

BaBarium

PbLead

The main group elements that must be memorized, indicated in green color for their symbols and names

4IVB

5VB

6VIB

7VIIB

8 9 1011IB

12IIB

←VIIIB→

TiTitanium

VVanadium

CrChromium

MnManganese

FeIron

CoCobalt

NiNickel

CuCopper

ZnZinc

AgSilver

PtPlatinum

AuGold

HgMercury

The transition metal elements that must be memorized, indicated in red color of their symbols and names

Exercise 1

Write names or symbols of the following elements.

1. Ca 8 . tin2. K 9. silicon3. Co 10. gold4. Mn 11. copper5. Cr 12. carbon6. Fe 13. neon7. P 14. bromine

NAMING BINARY IONIC COMPOUNDS (CONTAINING TWO DIFFERENT ELEMENTS)

Part II

Naming Binary Ionic Compounds

An ionic compound is a chemical compound in which ions are held together by the electrostatic forces between oppositely charged bodies.

Usually, the positively charged portion consists of metal cations (e.g., Na+) and the negatively charged portion consists of anions (e.g., Cl-).

Formation of An Ionic Compound

Cl

Cl-

e -

A sodium atom loses an electron to form a positive ion (cation): Na+.A chlorine atom gains an electron to form a negative ion (anion): Cl-.The cation and the anion are held together by the electrostatic forces (ionic bond) to form an ionic compound.

Na

Na+

Rules for Naming Binary Ionic Compounds

1. When naming cations, the name of the element is used.

2. When naming anions that are derived from an atom of the element, the name of the element is modified with the suffix –ide added.

3. Write the symbol of the cation first, and then the symbol of the anion.

For example: Chlorine (Cl) is the name of the element. When a chlorine atom gains an electron, it becomes an anion, chloride (Cl-).

NaCl

Formation of Magnesium Chloride

MgCl

e- e-

Write the formula with the positive & negative charges balanced. Mg 2+ + 2 Cl- MgCl2

Mg2+

Cl

Cl- Cl-

A subscript “2” is used to indicate number of chloride ion present in a magnesium chloride compound.

4. Compounds are electrically neutral, thus the total number of cations and anions must be such that positive and negative charges balance to zero.

5. The number of each ion present in the compound is designated by a subscript following its chemical symbols. For example, an aluminum oxide compound consists of 2 aluminum cation (Al3+) and 3 oxide anions (O2-).

Rules for Naming Binary Ionic Compounds(Continued)

MgCl2

Al2O3

15VA

16VIA

17VIIA

18VIIIA

1IA

2IIA

13IIIA

3 2 1 0 +1 +2 +3

1H

2He

3Li

4Be

7N

8O

9F

10Ne

11Na

12Mg

13Al

15P

16S

17Cl

18Ar

19K

20Ca

Transition Metal

Elements

31Ga

35Br

36Kr

37Rb

38Sr

53I

54Xe

55Cs

56Ba

A modified periodic table useful for writing formulas for binary ionic compounds. The numbers in blue indicate the common charges of cations and anions after these atoms gain or lose electrons.

Metals Non-metals

Examples of Binary Ionic Compounds

Full Name Name of Cation Name of Anion Chemical Formula

sodium chloride sodium (Na+) chloride (Cl-） NaCl

lithium bromide lithium (Li+) bromide (Br-) LiBr

calcium iodide calcium (Ca 2+) Iodide (I-) CaI2

aluminum sulfide aluminum (Al3+) sulfide (S2-) Al2S3

potassium oxide potassium (K+) oxide (O2-) K2O

lithium hydride lithium (Li+) hydride (H-1) LiH

barium nitride barium (Ba2+) nitride (N3-) Ba3N2

strontium phosphide strontium (Sr2+) phosphide (P3-) Sr3P2

Some metals can form cations with different charges. These cations can be named using two systems:

(a) Stock System:The charges of cations can be described by using Roman numerals.

Ex. Iron can form two cations: Fe2+ & Fe3+ FeCl2: iron(II) chlorideFeCl3: iron(III) chloride(pronounce: iron-two chloride; iron-three chloride)(b) Classical system:Assign the ending “ous” to the cations with fewer positive charges and the ending “ic” to the cations with more positive charges

Ex. Iron can form two cations: Fe2+ & Fe3+ FeCl2: ferrous chlorideFeCl3: ferric chloride

Element CationsNames, Charges

chromium, Cr chromium(II)(chromous) +2 chromium(III)

(chromic) +3

cobalt, Co cobalt(II)(cobaltous) +2 cobalt(III)

(cobaltic) +3

copper, Cu copper(I)(cuprous) +1 copper(II)

(cupric) +2

iron, Fe iron(II)(ferrous) +2 iron(III)

(ferric) +3

lead, Pb lead(II)(plumbous) +2 lead(IV)

(plumbic) +4

manganese, Mn manganese(II)(manganous) +2 manganese(III)

(manganic) +3

mercury, Hg mercury(I)(mercurous) +1 mercury(II)

(mercuric) +2

nickel, Ni nickel(II)(nickelous) +2 nickel(III)

(nickelic) +3

tin, Sn tin (II)(stannous) +2 tin(IV)

(stannic) +4

Naming of Cations Using the Classical and Stock Systems:

Additional Examples of Binary Ionic Compounds

Chemical Formula Name of Cation Name of

AnionName

(Stock System)Name

(Classical System)

FeF2(Fe2+)

iron(II), ferrous fluoride (F-) iron(II) fluoride ferrous fluoride

FeF3(Fe3+)

iron(III), ferric fluoride (F-) iron(III) fluoride ferric fluoride

Cu2O (Cu+)

copper(I), cuprous oxide (O2-) copper(I) oxide cuprous oxide

CuO (Cu2+)copper(II), cupric oxide (O2-) copper(II) oxide cupric oxide

PbBr2(Pb2+)

lead(II), plumbousbromide

(Br-)lead(II)

bromideplumbousbromide

PbBr4(Pb4+)

lead(IV), plumbicbromide

(Br-)lead(IV)bromide

plumbicbromide

Exercise 2Give the names or formulas of the following binary

ionic compounds. If a compound can be named by both the Stock and the Classical systems, provide both names.

1. CaO2 8. aluminum chloride

2. NaH 9. calcium phosphide3. Mg3N2 10. stannous oxide

4. FeI3 11. ferric bromide

5. CuCl 12. ferrous bromide6. CuCl2 13. barium nitride

7. Ba3P2 14. nickel(III) chloride

NAMING IONIC COMPOUNDS CONTAINING POLYATOMIC IONS

Part III

IIIA IVA VA VIA VIIA

VIB VIIB

BBO3

3-

borate

CCO3

2-

carbonate

NNO3

-

nitrate{NO2

-}{nitrite}

O F

SiSiO4

4-

silicate

PPO4

3-

phosphate{PO3

3-}{phosphite}

SSO4

2-

sulfate{SO3

2-}{sulfite}

ClClO3

-

chlorate {ClO2

-}{chlorite}

CrCrO4

2-

chromateCr2O7

2-

dichromate

MnMnO4

2-

manganateMnO4

-

permanganate

BrBrO3

-

bromate

IIO3

-

iodate

An oxo-anion usually contains two elements in which one of them must be oxygen. The oxo-anions of some elements (in blue) can have either a suffix -ate or -ite added to the root names of the elements. For example, SO4

2- and SO32- are oxo-anions of sulfur

element. Their names are sulfate and sulfite, respectively.

Names of Some Oxo-Anions

Names of Common Polyatomic Ions

Formula of Ion Name of Ion Formula

of Ion Name of ion Formula of Ion Name of Ion

NO2- nitrite NO3

- nitrate SCN- thiocyanate

SO42- sulfate HSO4

- hydrogen sulfate bisulfate BrO3

- bromate

SO32- sulfite HSO3

- hydrogen sulfitebisulfite AsO3

3- arsenite

CO32- carbonate HCO3

- bicarbonatehydrogen carbonate AsO4

3- arsenate

MnO4- permanganate CrO4

2- chromate Cr2O72- dichromate

PO43- phosphate HPO4

2- hydrogen phosphate H2PO42- dihydrogen

phosphate

ClO2- chlorite ClO3

- chlorate ClO4- perchlorate

ClO- hypochlorite IO3- iodate IO4

- periodate

Names of Common Polyatomic Ions (cont.)Formula Ion

NH4+ ammonium

Hg22+ mercury(I)

(mercurous)CN cyanideOH hydroxideO2

2 peroxide

SCN thiocyanateC2H3O2

(or CH3COO-) acetateCHO2

- (or HCOO-) formateC2O4

2- (or -OOC-COO-) oxalate

Examples of Ionic Compounds with Polyatomic Ions

Formula Name of Cation Name of Anion Stock System

Classical System

NiSO4(Ni2+)

nickel(II), nickelous sulfate(SO42-） nickel(II)

sulfatenickelous

sulfate

Ni2(SO4)3(Ni3+)

nickel(III), nickelic sulfate(SO42-） nickel(III)

sulfatenickelicsulfate

(NH4)2HPO4 (NH4+), ammonium hydrogen

phosphate(HPO42-)

ammoniumhydrogen

phosphate

ammonium hydrogen

phosphate

Al(CH3COO)3 Al3+, aluminum acetate(CH3COO -) aluminum acetate

aluminum acetate

Hg2(NO2)2

(Hg22+)

mercury(I) mercurous

nitrite(NO2-） mercury(I)

nitritemercurous

nitrite

Hg(NO2)2

(Hg2+)mercury(II)

mercuricnitrite(NO2

-） mercury(II)nitrite

mercuricnitrite

Exercise 3

Give the names or formulas of the following ionic compounds with polyatomic ions. If a compound can be named by both the Stock and the Classical systems, provide both names.

1. CaSO3 8. calcium phosphate

2. NaHCO3 9. cuprous sulfite

3.Hg2(NO3)2 10. ammonium nitrite

4. Hg(NO2)2 11. ferrous dihydrogen phosphate

5. Cu(CH3COO)2 12. barium cyanide

6. Ba(SCN)2 13. potassium permanganate

7. Na2Cr2O7 14. plumbous carbonate

NAMING ACIDS AND BASES Part IV

Formula Pure Substance Aqueous SolutionHCl hydrogen chloride hydrochloric acid

HBr hydrogen bromide hydrobromic acid

HI hydrogen iodide hydroiodic acid

H2S hydrogen sulfide hydrosulfuric acid

HCN hydrogen cyanide hydrocyanic acid

A. Acids without oxygen atoms

An acid is a substance that ionizes in water to produce hydrogen ions (H+). A base is a substance that ionizes in water to produce hydroxide ions (OH-).

The following compounds are named depending on whether they are present as pure substances or are dissolved in water to form aqueous solutions .

B. Common oxo-anions and their corresponding oxo-acids.

Element Oxo-Anion Oxo-Acidboron BO3

3 borate H3BO3 boric acid

nitrogen NO3 nitrate HNO3 nitric acid

phosphorusPO4

3 phosphate H3PO4 phosphoric acid

PO33 phosphite H3PO3 phosphorous acid

sulfurSO4

2 sulfate H2SO4 sulfuric acid

SO32 sulfite H2SO3 sulfurous acid

chlorine

ClO hypochlorite HClO hypochlorous acid

ClO2 chlorite HClO2 chlorous acid

ClO3 chlorate HClO3 chloric acid

ClO4 perchlorate HClO4 perchloric acid

bromine BrO3 bromate HBrO3 bromic acid

iodine IO3 iodate HIO3 iodic acid

C. Common organic acids

Formula Name

HCOOH (CH2O2) formic acid

CH3COOH (C2H4O2) acetic acid

HOOCCOOH (C2H2O4) oxalic acid

D. Bases

Formula Name Formula Name

NaOH sodium hydroxide LiOH lithium hydroxide

KOH potassium hydroxide Sr(OH)2 strontium hydroxide

Mg(OH)2 magnesium hydroxide Ca(OH)2 calcium hydroxide

Ba(OH)2 barium hydroxide AgOH silver hydroxideZn(OH)2 zinc hydroxide Al(OH)3 aluminum hydroxide

Hg2(OH)2mercury(I) hydroxidemercurous hydroxide Hg(OH)2

mercury(II) hydroxidemercuric hydroxide

CuOH copper(I) hydroxidecuprous hydroxide Cu(OH)2

copper(II) hydroxidecupric hydroxide

Ni(OH)2nickel(II) hydroxidenickelous hydroxide Ni(OH)3

nickel(III) hydroxidenickelic hydroxide

Co(OH)2cobalt(II) hydroxidecobaltous hydroxide Co(OH)3

cobalt(III) hydroxidecobaltic hydroxide

Pb(OH)2lead(II) hydroxide

plumbous hydroxide Cr(OH)3chromium(III) hydroxide

chromic hydroxide

Exercise 4

Give the names or formulas of the following acids and bases. If an acid or a base can be named by both the Stock and the Classical systems, provide both names.

1. HF (aqueous solution) 8. nitric acid

2. H2SO3 9. aluminum hydroxide

3. H2CO3 10. ferric hydroxide

4. H2S (pure substance) 11. cuprous hydroxide

5. Hg2(OH)2 12. hydrocyanic acid

6. Fe(OH)2 13. nitrous acid

7. H3PO4 14. sulfuric acid

NAMING HYDRATESPart V

Hydrates – compounds that have a specific number of water molecules attached to them.

Examples:

(1) BaCl2·2H2O

(2) CuSO4·5H2O

(3) MgSO4·7 H2O

The First Ten Greek Prefixes

Greek Prefix Number

mono- 1di- 2tri- 3

tetra- 4penta- 5hexa- 6hepta- 7octa- 8nona- 9deca- 10

Examples of Hydrates and Their Names

(1) BaCl2·2H2O

Name: barium chloride dihydrate(2) CuSO4·5H2O

Name : copper(II) sulfate pentahydrate (Stock System)

Or cupric sulfate pentahydrate (Classical System)

(3) MgSO4·7 H2O

Name: magnesium sulfate heptahydrate

The Greek prefixes are used to indicate the number of water molecules in hydrates.

Exercise 5

Give the names or formulas for the following hydrates. If a hydrate can be named by both the Stock and the Classical systems, provide both names.

(1) LiCl·H2O (6) barium chloride dihydrate

(2) MgSO4·7H2O (7) sodium carbonate decahydrate

(3) CoCl2·6H2O (8) ferrous sulfate hexahydrate

(4) CuSO4·5H2O (9) strontium nitrate tetrahydrate

(5) Na2SO4 10H∙ 2O (10) manganese(II) nitrate tetrahydrate

NAMING BINARY MOLECULAR COMPOUNDS(CONTAINING TWO ELEMENTS, BUT DON’T CONTAIN CATIONS AND ANIONS)

Part VI

Rules for Naming Binary Molecular Compounds

1.When naming the first element, the name of the element is used.

2.Then name the second element by taking the first part of the element name and adding the suffix “ide”.

3.Use Greek prefixes to denote the number of atoms of each element present.

4.The prefix “mono” can be omitted for the first element.

5.For oxides, the ending “a” in the prefix is sometimes omitted.

Examples of binary molecular compounds: CO2, CCl4

Examples

CO: carbon monoxide (not monocarbon monoxide)

CO2: carbon dioxide

SO3: sulfur trioxide

N2O4: dinitrogen tetroxide (not tetraoxide)

PCl5: phosphorus pentachloride

S2F10: disulfur decaflouride

An exception to the use of Greek prefixes involves molecular compounds containing hydrogen

Traditionally, many of these compounds are called either by their common names or by names that do not specifically indicate the number of H atoms present.

Examples:CH4 - methane; NH3 – ammonia; PH3 –

phosphineH2O- water; H2S – hydrogen sulfide; SiH4 -silane

Exercise 6

Give the names or formulas for the following binary molecular compounds.

1. NO 8. dinitrogen monoxide

2. SO2 9. boron trichloride

3. Cl2O7 10. diarsenic pentoxide

4. PBr3 11. sulfur hexachloride

5. SF6 12. nitrogen triiodide

6. P2O5 13. carbon tetra bromide

7. CCl4 14. diphosphorus pentoxide

AcknowledgementsThe authors would like to thank Ali Bazzi, Ogie Stewart and Ruixiao Zuo for their valuable comments and suggestions that were of great help in preparing and improving this module.

The authors would like to thank Annette Sieg, Assistant Director of SLC, as well as the SLC staff for their help and technical support.

Exercise 1 – Key

Write names or symbols of the following elements

1. Ca calcium 8 . tin Sn2. K potassium 9. silicon Si3. Co cobalt 10. gold Au4. Mn manganese 11. copper Cu5. Cr chromium 12. carbon C6. Fe iron 13. neon Ne7. P phosphorus 14. bromine Br

Exercise 2 - KeyGive the names or formulas of the following binary ionic compounds. If a compound can be named by both the Stock and the Classical systems, provide both names.

1. CaO2 calcium peroxide

2. NaH sodium hydride3. Mg3N2 magnesium nitride

4. FeI3 ferric/iron(III) iodide

5. CuCl cuprous/copper(I) chloride6. CuCl2 cupric/copper(II) chloride

7. Ba3P2 barium phosphide

8. aluminum chloride AlCl3

9. Calcium phosphide Ca3P2

10. Stannous oxide SnO11. Ferric bromide FeBr3

12. Ferrous bromide FeBr2

13. Barium nitride Ba3N2

14. Nickel (III) chloride NiCl3

Exercise 3 - Key Give the names or formulas of the following ionic compounds with polyatomic ions. If a compound can be named by both the Stock and the Classical systems, provide both names.

1. CaSO3 calcium sulfite

2. NaHCO3 sodium hydrogen carbonate

or sodium bicarbonate3.Hg2(NO3)2 mercurous/mercury(I) nitrate

4. Hg(NO2)2 mercuric/mercury(II) nitrite

5. Cu(CH3COO)2 cupric/copper(II) acetate

6. Ba(SCN)2 barium thiocyanate

7. Na2Cr2O7 sodium dichromate

8. calcium phosphate Ca3(PO4)2

9. cuprous sulfite Cu2SO3

10. ammonium nitrite NH4NO2

11. ferrous dihydrogen phosphate Fe(H2PO4)2

12. barium cyanide Ba(CN)2

13. potassium permanganate KMnO4

14. plumbous carbonate PbCO3

Exercise 4 - KeyGive the names or formulas of the following acids and bases. If an acid or a base can be named by both the Stock and the Classical systems, provide both names.

1. HF (aqueous solution) hydrofluoric acid

2. H2SO3 sulfurous acid

3. H2CO3 carbonic acid

4. H2S (pure substance) hydrogen sulfide

5. Hg2(OH)2 mercurous/mercury(I) hydroxide

6. Fe(OH)2 ferrous/iron (II) hydroxide

7. H3PO4 phosphoric acid

8. nitric acid HNO3

9. Aluminum hydroxide Al(OH)3

10. Ferric hydroxide Fe(OH)3

11. Cuprous hydroxide CuOH12. Hydrocyanic acid HCN13. Nitrous acid HNO2

14. Sulfuric acid H2SO4

Exercise 5 - KeyGive the names or formulas for the following hydrates. If a hydrate can be named by both the Stock and the Classical systems, provide both names.

(1) LiCl·H2O lithium chloride monohydrate

(2) MgSO4·7H2O magnesium sulfate heptahydrate

(3) CoCl2·6H2O cobaltous/cobalt (II) chloride hexahydrate

(4) CuSO4·5H2O cupric/copper (II) sulfate pentahydrate

(5) Na2SO4 10H∙ 2O sodium sulfate decahydrate

(6) barium chloride dihydrate BaCl2·2H2O

(7) sodium carbonate decahydrate Na2CO3·10H2O

(8) ferrous sulfate hexahydrate FeSO4·6H2O

(9) Strontium nitrate tetrahydrate Sr(NO3)2·4H2O

(10) manganese (II) nitrate tetrahydrate Mn(NO3)2·4H2O

Exercise 6 - KeyGive the names or formulas for the following binary molecular compounds.

1. NO nitrogen monoxide 8. dinitrogen monoxide

N2O

2. SO2 sulfur dioxide 9. boron trichloride

BCl3

3. Cl2O7 dichlorine heptoxide 10. diarsenic pentoxide

Ar2O5

4. PBr3 phosophorus tribromide 11. sulfur hexachloride SCl6

5. SF6 sulfur hexafluoride 12. nitrogen triiodide NI3

6. P2O5 diphosphorus pentoxide 13. carbon tetrabromide CBr4

7. CCl4 carbon tetrachloride 14. diphosphorus pentoxide P2O5