Ionic Bonding

Naming Ionic Compounds

Naming Ionic Compounds

• The same as naming individual ions.

• Cation, Electron Donor, or Metal in compound is said first.

• Anion name is changed to …….ide and said second.

Examples

• Sodium Chloride• Magnesium Oxide• Lithium Nitride• Potassium Bromide

Using the correct Name

1)K2S 7) SrS

2) LiBr 8) Al2O3

3) Sr3P2 9) MnO

4) BaCl2 10) ZnO

5) NaBr 11) ZnCl2

6) MgF2 12) Cu2O

Notation

Ionic Notation• 3 Na+1

• 1 PO4-3

Ionic Compound Formula• NaCl• CaCl2

• Na3(PO4)

FormulasRules for Writing Formulas• Metallic Donor is always written first.• Nonmetallic Receiver is written second.• Write the number of atoms required to

balance the formula as subscripts after the element in compound.– NaCl– MgO– MgCl2

The Ionic Compound

NaCl

Writing & NamingIonic Compounds

Na+1 & Br-1

Writing & NamingIonic Compounds

Ca+2 & Br-1

Writing & NamingIonic Compounds

K+1 & O-2

Writing & NamingIonic Compounds

Li ? & N ?

HW: Write the Name of the Compound

1)MgS 7) KBr

2) Ba3N2 8) FeO

3) NaI 9) SrF2

4) Li2S 10) CaO

5) Na3P 11) Al2O3

6) KCl 12) Fe2O3

Formulae of binary ionic compounds

• Binary – only two elements present• The rules –– symbol for the cation first, followed by the symbol

for the anion.– Determine the lowest whole number ratio of ions

that will provide a net charge of zero• The ‘crossover’ method is another way to

determine formulae (check page 79)• Work through the Sample Problems page 80,81

Review

• Complete the revision questions page 81 (13 – 16)

Ions of Variable Charge

• Some transition metals have quite complicated arrangement of electrons and may be able to form more than one ion. Such ions have different charges.

• This is very significant as ions of the same element with different charges have different physical and chemical properties.

• Eg – a solution of Cr6+ is orange, whereas a solutions of Cr3+ is yellow.

Ions of Variable Charge

• Iron can form FeO (black) and Fe2O3 (brown), each with different physical and chemical properties. Therefore you must name them differently.

• They cannot each be called iron oxide.• Therefore black FeO containing Fe2+ ions is called

iron (II) oxide.• The brown Fe2O3 contains Fe3+ ions and is name

iron (III) oxide.

Ions of Variable Charge

• Metal ions that form more than one cation include iron (II) and (III), copper (I) and (II), and mercury (I) and (II).

• Note the roman numeral do not indicate the numbers of ions present in the compound, only the charge of the ion.

Ions of Variable Charge

• Work through the Sample Problem page82

Review

• Complete the revision questions page 82 (17,18)

HW: Write the Correct Formula1)Magnesium Oxide

2) Lithium Bromide

3) Calcium Nitride

4) Sodium Sulfide

5) Copper (I) Sulfide

6) Copper (II) Sulfide

Practice Exercise #11. Which will donate, Which will receive?2. How many will be donated/received?3. Write the Ionic Notation of each.4. Write the formula for each of the following.

– Lithium Oxide– Potassium Chloride– Sodium Nitride– Calcium Chloride– Magnesium Sulfide– Barium Nitride– Aluminum Fluoride – Aluminum Oxide– Aluminum Nitride

Polyatomic ions

• A polyatomic ion is a group of tightly bound atoms that behaves as a single unit and carries an overall charge. It may be a positively or negatively charged ion.

• The carbonate ion is composed of one carbon atom and three oxygen atoms.

• The whole group of four atoms carries a negative two charge.

Polyatomic Ions

• Compound Ions

• A group of COVALENTLY bonded atoms that have a net charge (anion or cation)

• Most, but not all are Anions.

Polyatomics• SO4

-2 Sulfate

• SO3-2 Sulfite

• NO3-1 Nitrate

• NO2-1 Nitrite

• CO3-2 Carbonate

• CN-1 Cyanide• OH-1 Hydroxide• NH4

+1 Ammonium

Na3PO4

Na

P

O

O

O

O

P O

PO4-3 Phosphate can

accept 3 electrons.

When it does it has a negative 3 charge.

It is therefore called a………..

O

O

O

P O

Na

Na

Na

Sodium Phosphate

Na3PO4

Practice Exercise #3Give the Ionic Notation and Formula for each.– Potassium Sulfate– Magnesium Sulfite– Aluminum Nitrate– Sodium Nitrite– Lithium Carbonate– Sodium Cyanide– Barium Hydroxide– Ammonium Chloride– Ammonium Hydroxide

Draw/Diagram Magnesium Sulfite

Practice Exercise #4

• Write out the Ionic Notation, Formula and Names of the following ionic compounds:– Li and F - Na and CO3

-2

– Na and S - Li and OH-1

– K and Br - NH4+1 and Cl

– Rb and O - Ca and SO4-2

– Ca and Cl - NH4+1 and OH-1

– Mg and SO3-2 - Na and CN-1

– Al and NO3-1 - NH4

+1 and SO4-2

Polyatomic ions

• Work through the Sample Problem pages 84, 85

Review

• Complete the revision questions page 85 (19 – 21)

Hydrated ionic compounds

• A number of ionic compounds, called hydrates, produce water when they decompose upon heating. When the formula of a hydrated compound is written, the number of water molecules is also included.

• Eg. – the formula for iron(II) sulphate octahydrate is written as FeSO4

. 8H2O. • This formula indicates that eight molecules of water

are bonded within the ionic crystal for every one formula unit of FeSO4

• Work through the Sample Problem page 86

Review

• Complete the revision question page 86 (22)• Complete the multiple choice questions pages

86, 87• Complete review questions 1, 3, 5, 6, 8, 10, 11,

13• Complete the Exam Practice Questions• Try this ionic compound construction kit -

Ionic Compounds