C H A P T E R 7

CHEMICAL NOMENCLATURE

MOLECULAR COMPOUNDS•Consists of nonmetals covalently bonded to:•Nonmetals •Metalloids

MOLECULAR COMPOUNDSFirst Element:1. Only use a prefix if there is more than one2. Simply state the element nameSecond Element:

3. Always use a prefix4. Change the ending of the second word to –ide5. Drop any double vowels (except for i)

NO2 nitrogen dioxide

N2O dinitrogen monoxide

TOXIC!

Laughing Gas

PREFIXES FOR NAMING COVALENT COMPOUNDS

Number of atoms/example

• Mono 1 CO • Di 2 SO2

• Tri 3 SO3

• Tetra 4 CCl4• Penta 5 PCl5

Number of atoms/example

• Hexa 6 SCl6• Hepta 7 IF7

• Octa 8 Np3O8

• Nona 9 I4O9

• Deca 10 S2F10

MOLECULAR COMPOUND EXAMPLES1. CO2

2. SO2

3. N2O4. N2O3

5. N2O4

6. PCl37. NH3

8. P2O5

9. SiO2

10.OF2

1. Carbon Dioxide2. Sulfur Dioxide3. Dinitrogen monoxide4. Dinitrogen Trioxide5. Dinitrogen Tetroxide6. Phosphorus Trichloride7. Ammonia (an exception)8. Diphosphorus Pentoxide9. Silicon Dioxide10. Oxygen Difluoride

DIATOMIC ELEMENTSSome elements do not like to be alone…

so they bond to themselves! DO NOT USE PREFIXES – just name the element.

7HOFBrINCl

ACIDS• acid: is a type of molecular compound

• Binary acids are acids that consist of two elements, hydrogen and usually a halogen.

• Use “hydro” to represent the hydrogen• For the 2nd element, write the root word and add “ic acid”

• example: HCl = hydrochloric acid

ACIDS, CONTINUED• Oxyacids are acids that contain

hydrogen, oxygen, and a third element (usually a nonmetal).• Naming is based on polyatomic ion:• First, name the polyatomic ion root name• Second, add the suffix as follow:

• ates = ic acids• ites = ous acids 2

4SO

3NO

34PO

sulfuric acid H2SO4 sulfate

nitric acid HNO3 nitrate

phosphoric acid H3PO4 phosphate

ACID NOMENCLATURE1. HNO3

2. HCl3. H2SO4

4. H2SO3

5. HC2H3O2

6. HBr7. HNO2

8. H3PO4

9. H2S10.H2CO3

1. Nitric acid2. Hydrochloric acid3. Sulfuric acid4. Sulfurous acid5. Acetic acid6. Hydrobromic acid7. Nitrous acid8. Phosphoric acid9. Hydrosulfuric acid10. Carbonic acid

The ionic compound NaCl

IONIC COMPOUNDS• consist of a combination of cations and anions

formed from a transfer of electrons• the formula is always the same as the empirical formula• the sum of the charges on the cation(s) and anion(s) in

each formula unit must equal zero

Al2O3

2 x +3 = +6 3 x -2 = -6

Al3+ O2-

CaBr2

1 x +2 = +2 2 x -1 = -2

Ca2+ Br-

Na2CO3

1 x +2 = +2 1 x -2 = -2

Na+ CO32-

FORMULA OF IONIC COMPOUNDS

Aluminum oxide1. Write ions2. Find LCM3. Make equal (these

#’s become subscript)

Calcium bromide4. Write ions5. Find LCM6. Make equal (these

#’s become subscript)

Sodium carbonate7. Write ions8. Find LCM9. Make equal (these

#’s become subscript)

NAMING IONIC COMPOUNDSRULE 1

Metal – Nonmetal1. Write the metal (positive ion) first by just saying the

metal name or ammonium2. Change the ending of the second word to -ide

RULE 1 EXAMPLES

1. KBr2. CaBr2

3. LiF4. Li2O5. MgO6. BaS7. K3P8. Na3N

1. Potassium Bromide2. Calcium Bromide3. Lithium Fluoride4. Lithium Oxide5. Magnesium Oxide6. Barium Sulfide7. Potassium Phosphide8. Sodium Nitride

NAMING IONIC COMPOUNDSRULE 2

Polyatomic Ions1. DO NOT CHANGE ANYTHING!2. When you have NH4, change the second word to -ide

RULE 2 EXAMPLES

1. BaSO4

2. BaSO3

3. Na2CO3

4. NaHCO3

5. (NH4)3PO4

6. NH4OH

1. Barium Sulfate2. Barium Sulfite3. Sodium Carbonate4. Sodium Bicarbonate5. Ammonium Phosphate6. Ammonium Hydroxide

NAMING IONIC COMPOUNDSRULE 3

Transition Metals1. Can have more than one type of charge2. Write the charge number in roman numerals

RULE 3 EXAMPLES1. Cu2O2. CuO3. FeCl24. FeCl35. SnCl46. Mn2O3

7. PbS

1. Copper (I) Oxide2. Copper (II) Oxide3. Iron (II) Chloride4. Iron (III) Chloride5. Tin (IV) Chloride6. Manganese (III) Oxide7. Lead (II) Sulfide

NaOH sodium hydroxide

KOH potassium hydroxide

Ba(OH)2 barium hydroxide

BASES• Base: a substance that yields hydroxide ions

(OH-) when dissolved in water.

NAME TO FORMULA – LEAST COMMON MULTIPLE

1. Lithium fluoride2. Sodium sulfide3. Aluminum bromide4. Iron (III) oxide5. Sulfuric acid6. Calcium carbonate7. Magnesium acetate8. Lead (IV) oxide9. Ammonium sulfite10.Barium hypochlorite