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Chemical Nomenclature (a.k.a. naming compounds)

Chemical Nomenclature (a.k.a. naming compounds). Antoine Lavoisier (1743-1794) “ Father of Modern Chemistry ” Major contributions included –E–Established

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Page 1: Chemical Nomenclature (a.k.a. naming compounds). Antoine Lavoisier (1743-1794) “ Father of Modern Chemistry ” Major contributions included –E–Established

Chemical Nomenclature

(a.k.a. naming compounds)

Page 2: Chemical Nomenclature (a.k.a. naming compounds). Antoine Lavoisier (1743-1794) “ Father of Modern Chemistry ” Major contributions included –E–Established

Antoine Lavoisier (1743-1794)

“Father of Modern Chemistry”

• Major contributions included– Established the Law of Conservation of Mass– Introduced scientific experimenting via the BALANCE– Invented a system of chemical nomenclature (still used

in part today!)

– Wrote the 1st modern chemical textbook– Introduced the the 1st 33 elements.– Demonstrated that water cannot be transmuted to

earth– AND MORE …

Page 3: Chemical Nomenclature (a.k.a. naming compounds). Antoine Lavoisier (1743-1794) “ Father of Modern Chemistry ” Major contributions included –E–Established

Types of Compounds The Two main types are:

• Ionic– Made up of ions (both positive and negative charge)

– Must have no net charge (i.e. combined charge of zero)

– Depend on the attraction between positive and negative charges of the ions

– Usually a metal is present as a cation

• Molecular (or covalent)– Made up of atoms that share their outer electrons– Charge plays no direct role in their formation– Usually combination of two or more nonmetals.

Page 4: Chemical Nomenclature (a.k.a. naming compounds). Antoine Lavoisier (1743-1794) “ Father of Modern Chemistry ” Major contributions included –E–Established

Naming Compounds• Easiest way to identify an ionic compound is

whether or not it has a metal present:– Yes ionic (e.g. CaCl2)

– No covalent (e.g. CCl4)

• Ionic compounds are named using the stock system. (No use of prefixes)

• Covalent compounds require the use of Latin prefixes to indicate the number of each element present in one molecule

Page 5: Chemical Nomenclature (a.k.a. naming compounds). Antoine Lavoisier (1743-1794) “ Father of Modern Chemistry ” Major contributions included –E–Established

Naming Binary CompoundsA “simple” or binary compound is a compound made of

only 2 types of elements • When the first element is a metal:

• The first element (metal) keeps its full name• The non-metal goes by its root with the suffix “-ide” added

to the endExample: NaCl is sodium chloride

• When there are no metals present• Same as above except• Latin prefixes must be used to identify the number of each

element present in the compound

Example: CO2 is carbon dioxide

Page 6: Chemical Nomenclature (a.k.a. naming compounds). Antoine Lavoisier (1743-1794) “ Father of Modern Chemistry ” Major contributions included –E–Established

Ionic Charges & the Stock System– Group 1 metals form 1+ cations (Na+ sodium ion)– Group 2 metals form 2+ cations (Ca2+ calcium ion)– Group 13 metals form 3+ cations (Al3+ aluminum ion)– All other metals (i.e. the transitional metals, Pb, etc.) form more than one

type of cation• Roman numerals must be used to indicate the charge of the cation• Example:

Fe3+ is called iron(III)

FeCl3 is called iron(III) chloride

• Exceptions:Ag+, Cd2+ & Zn2+

– Group 15 nonmetals form 3- anions (N3- nitride ion)– Group 16 nonmetals form 2- anions (O2- oxide ion)– Group 17 nonmetals form 1- anions (Cl- chloride ion)– Group 18 nonmetals do not form ions (Zero charge)

Page 7: Chemical Nomenclature (a.k.a. naming compounds). Antoine Lavoisier (1743-1794) “ Father of Modern Chemistry ” Major contributions included –E–Established

Latin Prefixes for Naming Molecules1) Mono-2) Di-3) Tri4) Tetra-5) Penta-

CCl4 is carbon tetrachloride

6) Hexa-7) Hepta-8) Octa-9) Nona-10) Deca-

C3H8 is tricarbon octahydrideNotes:

1) Prefixes are used when the compound does not have a metal present (or when H is the first element in the formula)

2) Prefixes must be used for every element present in the compound

3) mono- is not used for the first element in a compound name (e.g. carbon dioxide)

Page 8: Chemical Nomenclature (a.k.a. naming compounds). Antoine Lavoisier (1743-1794) “ Father of Modern Chemistry ” Major contributions included –E–Established

Ionic Compounds containing Polyatomic ions

• Some ionic compounds are made up of polyatomic ions

• When you encounter this, do not freak out!!• Become familiar with the polyatomic ions on the

handout

Example: the nitrate ion (NO3-)

• The naming of this type of compound is similar to that for ionic compounds but no change in suffix.

Example: Ca(NO3)2 Calcium Nitrate

Page 9: Chemical Nomenclature (a.k.a. naming compounds). Antoine Lavoisier (1743-1794) “ Father of Modern Chemistry ” Major contributions included –E–Established

Oxy-Ions• Polyatomic Ions containing Oxygen can be

represented a number of different ways.

One less Oxygen in the formula change the suffix is changed from “ate” to “ite”. The ion’s charge, however, does not change.

Ex. (NO3)-1 Nitrate vs. (NO2)-1 Nitrite

If two less Oxygens the prefix “hypo-” is placed in front of the “ite” name.

Ex. (ClO)-1 hypo- Chlorite If one more Oxygen the prefix “per-” is placed in front of

the “ate” name.

Ex. (ClO4)-1 Per Chlorate

Page 10: Chemical Nomenclature (a.k.a. naming compounds). Antoine Lavoisier (1743-1794) “ Father of Modern Chemistry ” Major contributions included –E–Established

Acids– From the Latin term for “sour”{Acids are sour to the taste}

– Acids are substances that donate protons (H+) (usually when dissolved in water)

– Chemical formula usually begins with HExample: hydrochloric acid

HCl(aq) + H2O(l) H3O+ + Cl- (aq)

– Taste bitter– Usually metal containing hydroxides– Substances that accept protons (H+) when dissolved in waterExample: potassium hydroxide

KOH(aq) + H3O+ K+(aq) + H2O (l)

Bases

Page 11: Chemical Nomenclature (a.k.a. naming compounds). Antoine Lavoisier (1743-1794) “ Father of Modern Chemistry ” Major contributions included –E–Established

Naming AcidsLets separate acids into 2 types:

– Acids that contain oxygen– Acids that do not contain oxygen

Naming acids containing oxygen:– For acids containing “-ate” anions:

1. Use root of the anion (for sulfate, SO42-, use sulfur)

2. Add “-ic” suffix then end with “acid”

Example: H2SO4 is sulfuric acid

– For acids with “-ite” anions:1. Use root of the anion (for sulfite, SO3

2-, use sulfur) 2. Add “-ous” suffix then end with “acid”

Example: H2SO3 is sulfurous acid

Page 12: Chemical Nomenclature (a.k.a. naming compounds). Antoine Lavoisier (1743-1794) “ Father of Modern Chemistry ” Major contributions included –E–Established

Naming Acids (cont.)Naming acids not containing oxygen:

– Add “hydro-” prefix to beginning– Use root of the anion (i.e. Cl- use chlor)– Add “-ic” suffix then end with “acid”Example: HCl is hydrochloric acid

Name the following acids:HF

HNO2

HCN

H3PO4

Page 13: Chemical Nomenclature (a.k.a. naming compounds). Antoine Lavoisier (1743-1794) “ Father of Modern Chemistry ” Major contributions included –E–Established

Hydrate Molecules• A hydrate molecule is a ionic compound

that contains water molecules trapped inside the crystalline structure.

The Formula includes a dot followed by the number of water molecules

Ex: Copper(II) Sulfate Pentahydrate

CuSO4 · 5H2O

Page 14: Chemical Nomenclature (a.k.a. naming compounds). Antoine Lavoisier (1743-1794) “ Father of Modern Chemistry ” Major contributions included –E–Established

Hydrate Molecules

The Name of a hydrate molecule would include two separate names.

The name of the ionic compound followed by the term ___hydrate. A Greek Prefix would be used to represent the number of water molecules that are trapped.

CoCl2 · 2 H2O Colbalt(II) Chloride Dihydrate