chemical names and formulas

CHEMICAL NAMES and

FORMULAS

Chemistry I

SBC

Bill Palmer

CHEMICAL NAMES and FORMULAS

There are millions and millions of chemical compounds

Many have common namesSalt (sodium chloride)

Limestone (calcium carbonate)

Water (dihydrogen monoxide)

Chemist must use a systematic method for naming compounds


A CHEMICAL FORMULA tells two things

Elements in a compound

Number of atoms in the compound

This is a compound known as Octane

C8H18

There are 8 carbon atoms in one molecule of

octane

There are 18 hydrogen atoms in one molecule of octane


Aluminum Sulfate

Al2(SO4)3

2 aluminum atoms

This is called a sulfate= one sulfur atom and four

The 3 that there are 3 of the sulfates


Aluminum Sulfate

Al2(SO4)3

How many TOTAL Aluminum atoms?

How many TOTAL Sulfur atoms?

How M\many total Oxygen atoms?


Atoms have VALENCE NUMBERS based on their ability to gain or loose electrons

An ION is an atom that has gained or lost electrons


There are TWO types of ions

CATIONS are positive charged ionsThey have lost electrons

ANIONS are negatively charged ionsThey have acquired electrons


GROUP ONE metals lose electron and have a valence number of +1

Li+ Na+

GROUP TWO metals lose electron and have a valence number of +2

Be+2 M g+2

GROUP THREE metals lose electron and have a valence number of +3

Al+3


So now, on your BFF, write +1, +2, +3 above the correct group


Aluminum Sulfate

Al2(SO4)3

How many TOTAL Aluminum atoms? 2

How many TOTAL Sulfur atoms? 3

How M\many total Oxygen atoms? 12


GROUP FIFTEEN nonmetals gain electrons and have a valence number of -3

N3- P3-

GROUP SIXTEEN nonmetals lose electron and have a valence number of -2

O2- S2-

GROUP SEVENTEEN nonmetals lose electron and have a valence number of -1

F- Cl-


So now, on your BFF, write -1, -2, -3 above the correct group


Some elements in the form 2+, 3+ or even 1+ or 4+ ions

Some can form two ionsCopper can be 1+ or 2+

Iron can form 2+ or 3+

Vanadium forms 2+, 3+, and 4+

Look at Table 1 page 221


MONOATOMIC IONS are formed from as single element


NAMING MONOATOMIC IONSCations-just use elements name

K+ Potassium

Mg2+ Magnesium

Anions-Change the elements name to

-ide

Fluorine becomes Fluoride

Nitrogen becomes Nitride


BINARY COMPOUNDS are composed of two elements

For a compound to exist the valence numbers must = 0

Mg 2+, Br-, Br- makes a compound MgBr2

One magnesium atom combines with two Bromine atoms

WHAT IS THE NAME OF THIS COMPOUND?


WHAT IS THE NAME OF THIS COMPOUND?

Magnesium bromide


How can Al 3+ combine with O2- to form a compound?

Al2O3

Aluminum Oxide


Sample problem on page 223

Do Practice Problems 1 and 2 on 223


Stock System of Nomenclature uses standard rules for naming compounds

Some elements have two or more ions.Fe 2+ (iron II)

Fe 3+ (iron III)

Metals that form only one cation do not include a roman numeral

CuCl2 copper (II) chloride


Example:

CuCl2 copper (II) chloride

Name of cation Roman numeral indicating charge

Name of anion


Compounds with POLYATOMIC ionsContain several atoms that act as a unit

Oxyanions-contain oxygen

Some elements have more than one polyatomic ions

NO2- nitrite

NO3- nitrate


Compounds with POLYATOMIC ionsSometimes polyatomic ions can have types of oxyanions

ClO- Hypochlorite

ClO2- Chlorite

ClO3- Chlorate

ClO4- Perchlorate

Chart on page 226


Practice Problems 1-2, page 227


Naming BINARY MOLECULAR compounds

Chart of numerical

prefixes

1 Mono-

2 Di-

3 Tri-

4 Tetra-

5 Penta-

6 Hexa-

7 Hepta-

8 Octa-

9 Nona

10 Deca-

NUMBER NAME


What is:

P4O10

tetraphosphorous decoxide


Practice problems 1-2, page 229


Problems 1,2 page 227


Nitrogen and Oxygen can make several compounds

N2O Dinitrogen monoxide

NO Nitrogen

Monoxide

NO2 Nitrogen dioxide

N2O3 Dinitrogen trioxide

N2O4 Dinitrogen tetraoxide

N2O5 Dinitrogen pentoxide

FORMULA NAME


Practice problems 1-2, page 229


COVALENT COMPOUNDS are formed when compounds are formed by elements sharing electrons

IONIC COMPOUNDS are formed when compounds are formed by elements transferring electrons.


Covalent CompoundsSiC Silicon Carbide

SiO2 Silicon dioxide

Si3N4 Trisilicon tetranitride


ACIDS and SALTSBinary Acid = 2 elements=Hydrogen plus a halogen

Oxyacids = Hydrogen, oxygen, third element


Some binary Acids and oxyacids

HF

Hydrofluoric Acid

HNO2

Nitrous Acid

CH3COOH

Acetic Acid

(Vinegar)

HBr

Hydrobromic Acid

HNO2

Nitric Acid

HClO3

Chloric Acid

H3PO4

Phosphoric Acid

H2SO4

Sulfuric Acid

HClO4

Perchloric Acid


Problems 1-4, page 231


Two systems for naming compoundsStock system is more modern

chemical names and formulas

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