Chapter 6Naming Compounds

Use handout for notes.

Remember

Covalent – show sharing of e-

Ionic – show transfer of e-

Lewis Structures i.e. Electron Dot Diagrams Ionic – show transfer of e-

These have only 2 elements and are ionic (1 metal and 1 nonmetal).

Write the name of the cation (metal). Then write the name of the anion

(nonmetal) but end it with the suffix –ide. Examples: sodium chloride (NaCl) Calcium oxide (CaO)

Binary Ionic Compounds

Anion nonmetals form ions with negative charges.

Group number – 8 = charge Examples: nitrogen: 5-8=-3 Oxygen: 6-8=-2 Iodine: 7-8=-1

Anions

Element Ion Name Ion Symbol Ion Charge

Fluorine Fluoride F- -1

Chlorine Chloride Cl- -1

Bromine Bromide Br- -1

Iodine Iodide I- -1

Oxygen Oxide O2- -2

Sulfur Sulfide S2- -2

Nitrogen Nitride N3- -3

Phosphorus Phosphide P3- -3

Common Anions

The alkali metals (group 1A), alkaline earth metals (group 2A), and aluminum form ions with a positive charge equal to their number of valence electrons (or group number).

Examples:

Cations

Element Ion symbol Charge

Potassium K+ +1

Calcium Ca2+ +2

Aluminum Al3+ +3

The transition metals form cations differently.

They form more than 1 type of ion. Use a Roman numeral next to the ion name

to indicate its charge. Examples: copper can be copper (I) with a

+1 charge or copper (II) with a +2 charge

Cations

Element Ion Name Ion Symbol

Copper Copper (I) Cu+

Copper Copper (II) Cu2+

Iron Iron (II) Fe2+

Iron Iron (III) Fe3+

Lead Lead (II) Pb2+

Lead Lead (IV) Pb4+

Chromium Chromium (II) Cr2+

Chromium Chromium (III) Cr3+

Titanium Titanium (II) Ti2+

Titanium Titanium (III) Ti3+

Titanium Titanium (IV) Ti4+

Mercury Mercury (II) Hg2+

Transition Metal Cations

Common Ion Charges

1+

2+ 3+ NA 3- 2- 1-

0

Ionic Nomenclature

The total (net) charge of an ionic compound must be 0 (zero).

The cation and anion charges must cancel each other out.

Example: Copper (II) oxide– copper has a charge of

+2 and oxygen has a charge of -2 +2 cancels -2 to equal 0

Ionic Compounds

Crystal structure of ionic compounds

1. Titanium (II) sulfide 2. Copper (I) oxide 3. Lead (II) oxide 4. Lead (IV) nitride 5. Mercury (II) iodide

Which of these ionic compounds have a net charge of 0?

1. **Titanium (II) sulfide +2-2=02. Copper (I) oxide +1-2=-13. **Lead (II) oxide +2-2=04. Lead (IV) nitride +4-3=+15. Mercury (II) iodide +2-1=+1

Which of these ionic compounds have a net charge of 0?

Copper (1) oxide CuO Does not balance to 0 +1-2=-1 But 2 atoms of copper (1) would make it

equal 0 Cu20 +1+1-2=0

Balancing Compounds

Mercury (II) iodide +2-1=+1 HgI Does not balance to 0, but… HgI2 +2-1-1=0

Balancing Compounds

Lead (IV) nitride +4-3=+1 PbN Does not balance to 0, but… Pb3N4

+4+4+4-3-3-3-3=0 +12-12=0

Balancing Compounds

1. Iron (II) bromide2. Chromium (III) nitride3. Lead (IV) oxide4. Titanium (III) fluoride5. Lead (IV) phosphide

Write a balanced formula for the following compounds.

1. Iron (II) bromide FeBr2

2. Chromium (III) nitride CrN3. Lead (IV) oxide PbO2

4. Titanium (III) fluoride TiF3

5. Lead (IV) phosphide Pb3P4

Write a balanced formula for the following compounds.

The atoms in polyatomic ions are joined by covalent bonds but have a net + or – charge.

The prefix poly- means many. Polyatomic ions contain many ions. Example: Ammonium contains 1 nitrogen and 4

hydrogen atoms. -3+1+1+1+1=-3+4=+1 (net charge)

Polyatomic Ions

Ion Name Formula Ion Name Formula

Ammonium NH4+ Acetate C2H3O2-

Hydroxide OH- Peroxide O22-

Nitrate NO3- Permanganate MnO4-

Sulfate SO42- Hydrogen

sulfateHSO4-

Carbonate CO32- Hydrogen

carbonateHCO3-

Phosphate PO43- Hydrogen

phosphateHPO4

2-

Chromate CrO42- Dichromate Cr2O7

2-

Silicate SiO32- Hypochlorite OCl-

Polyatomic Ions

I will give you polyatomic ion formulas on the test.

There is a chart in your book on page 173 to use on classwork and homework.

Polyatomic Ions

Polyatomic ions can combine with metals to form compounds.

Put the polyatomic ion in parentheses when you write the formula.

Example: Iron (III) hydroxide Fe(OH)3

Iron has a +3 charge and hydroxide has a -1 charge. You must have 3 hydroxide ions to balance the iron and make the net charge 0.

Polyatomic Ions

1. Chromium (II) sulfate2. Lead (IV) hydroxide3. Mercury (II) acetate4. Copper (I) sulfate5. Titanium (IV) dichromate

See page 173 for the polyatomic ion formulas.

Write a balanced formula for the following.

1. Chromium (II) sulfate Cr(SO4)

2. Lead (IV) hydroxide Pb(OH)4

3. Mercury (II) acetate Hg(C2H3O2)2

4. Copper (I) sulfateCu2(SO4)

5. Titanium (IV) dichromate Ti(Cr2O7)2

Write a balanced formula for the following.

Ionic Nomenclature Consider the following:

◦ Does it contain a polyatomic ion? -ide, 2 elements no -ate, -ite, 3+ elements yes

◦ Does it contain a Roman numeral? Check the table for metals not in Groups 1 or 2.

◦ No prefixes!

IMPORTANT!!!!

These are called molecules. Name the most metallic element (the one

that appears the furthest left on the periodic table) first.

If both elements are in the same group, name the one closest to the bottom first.

Add the suffix –ide to the second element. Example: carbon dioxide

Naming Covalent Compounds

Use the Greek prefixes to indicate how many of each atom are in the molecule.

Naming Covalent Compounds

Number Prefix Number Prefix

1 Mono- 6 Hexa-

2 Di- 7 Hepta-

3 Tri- 8 Octa-

4 Tetra- 9 Nona-

5 Penta- 10 Deca-

N2O4

Dinitrogen tetraoxide Di = 2 nitrogens Tetra = 4 oxygens Because nitrogen is a group left of oxygen

name it first Because oxygen is named second, change it

to end in -ide

Naming Covalent Compounds

NO2

Mononitrogen dioxide If there is only 1 of the first element, it is

not necessary to use the mono- prefix. Nitrogen dioxide

Naming Covalent Compounds

1. NO2

2. P2F4

3. P2O5

4. CO5. N2S5

Name the following molecular compounds.

1. NO2 nitrogen dioxide

2. P2F4 diphosphorus tetrafluoride

3. P2O5 diphosphorus pentaoxide

4. CO carbon monooxide5. N2S5 dinitrogen pentasulfide

Name the following molecular compounds.

1. Nitrogen dioxide2. Diphosphorus tetrafluoride3. Carbon dioxide4. Dihydrogen oxide5. Dinitrogen tetraoxide

Write the name of the molecular compound.

1. Nitrogen dioxide NO2

2. Diphosphorus tetrafluoride P2F4

3. Carbon dioxide CO2

4. Dihydrogen oxide H2O

5. Dinitrogen tetraoxide N2O4

Write the name of the molecular compound.

N O F

Cl

Br

I

H

Molecular Nomenclature

The Seven Diatomic Elements

Br2 I2 N2 Cl2 H2 O2 F2