IONIC BONDING AND NOMENCLATURE. Ionic Bonding and Nomenclature Ionic Bonding Comparing the Properties of Ionic and Covalent Compounds Naming and Writing

IONIC BONDING AND NOMENCLATURE

Ionic Bonding and Nomenclature

Ionic Bonding

Comparing the Properties of Ionic and Covalent Compounds

Naming and Writing Formulas for Ions

Naming and Writing Formulas for Ionic Compounds

Metallic Bonding

Naming and Writing Formulas for Acids and Bases

Ionic BondingIonic bonding involves the transfer of valence electrons.

One atom loses one or more valence electrons to become a cation (positive ion).

The other atom gains one or more valence electrons to become an anion (negative ion).

Ionic compounds are electrically neutral. This means the total number of negative charges is equal to the total number of positive charges.

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Ionic BondingIonic bonding usually results from the bonding of a metal with a nonmetal.

For example, the alkali metals typically bond with the halogens to form an ionic compound commonly referred to as a salt.

The chemical formula for an ionic compound is referred to as a formula unit and not a molecule.

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Ionic BondingAt room temperature, crystals of ionic compounds exist as regular, three-dimensional arrangements of cations and anions held together by electrostatic attractions.

The arrangements are called crystal lattices.

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Ionic BondingHere is an example of the crystal lattice for sodium chloride. (Note: The lines between the ions are not bonds; they are reference lines showing the relative positions of Na+ and Cl-.)

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Using Lewis Dot Diagrams to Predict Formulas for Ionic Compounds

Lewis dot diagrams can be used to illustrate the transfer of valence electrons that occurs and to predict the chemical formula for an ionic compound.

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Example 1. Use Lewis dot diagrams to predict the formula for the ionic compound formed from sodium and chlorine.First draw the Lewis dot diagrams for sodium and for chlorine.

Next use arrows to illustrate the transfer of valence electrons.

The resulting chemical formula is NaCl. The compound formed is called sodium chloride.

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Example 2. Use Lewis dot diagrams to predict the formula for the ionic compound formed from calcium and iodine.

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First draw the Lewis dot diagrams for calcium and for iodine.


The resulting chemical formula is CaI2. The compound formed is called calcium iodide.

Example 3. Use Lewis dot diagrams to predict the formula for the ionic compound formed from barium and sulfur.

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First draw the Lewis dot diagrams for barium and for sulfur.


The resulting chemical formula is BaS. The compound formed is called barium sulfide.

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Use Lewis dot diagrams to predict the formula for the ionic compound formed from lithium and oxygen.

Chemical Formula Li2O

You Try It

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Use Lewis dot diagrams to predict the formula for the ionic compound formed from aluminum and nitrogen.

Chemical Formula AlN

You Try It

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Use Lewis dot diagrams to predict the formula for the ionic compound formed from magnesium and nitrogen.

Chemical Formula Mg3N2

Comparing the Properties of Ionic and Covalent Compounds

Characteristics of Ionic and Covalent Compounds

Characteristic Ionic CompoundNonpolar Covalent

Compound

Polar Covalent Compound

Representative Unit (smallest particle that has all of the properties)

Bond Formation

Type of Elements forming compounds

Physical State

Melting Point

Solubility in H2O

Electrical Conductivity of Aqueous Solution

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formula unit molecule

transfer of one or more valence electrons between atoms

sharing of electron pairs between atoms

Metal with a nonmetal nonmetals

Solid solid, liquid, or gas

high low

good electrolyte

insoluble solublesoluble

nonelectrolytepoor to nonelectrolyte (usually nonelectrolytes)

Daily Starter (12/3 & 12/4)The table below represents a student’s experimental results. Use the information to answer the questions below.

CompoundSolubility in

WaterConductivity in

WaterMelting Point

A Soluble Weak Electrolyte Low

B Soluble Strong Electrolyte High

C Insoluble Non Electrolyte Low

1. Which compound is polar covalent?

2. Which compound is nonpolar covalent?

3. Which compound is ionic?

A

C

B

Predicting Charges for Ions

The periodic table can be used to help predict the charge on an ion.

Remember:

Cations are formed when an loses one or more valence electrons. This is typical of metals.

Anions are formed when a metal gains one or more valence electrons. This is typical of nonmetals.

Symbols of Ions for Cations

The metals in groups 1, 2 and 13 lose electrons when they form ions.

Group 1 forms +1 ions.

Group 2 forms +2 ions

Group 13 forms +3 ions.Back to main menu

Naming and Writing Symbols for Cations

Element Symbol of Ion Name of Ion

Calcium

Sodium

Aluminum

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Ca2+ Calcium ion

Na+ Sodium ion

Al3+ Aluminum ion

You Try It. Write the symbol and name for each of the following ions.

Metals with More than One Common Oxidation Number

The metals in groups 3-12 are called transition metals.

They often have more than one common oxidation number (ionic charge).

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Metals with More than One Common Oxidation NumberHere are some of the more commonly used transition metals and their oxidation numbers. Notice that a Roman numeral is used to indicate the charge on the ion when naming the ions formed.

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Fe2+ Iron(II) ion Fe3+ Iron(III) ionCu+ Copper(I) ion Cu2+ Copper(II) ionHg2

2+ Mercury(I) ion Hg2+ Mercury(II) ionPb2+ Lead(II) ion Pb4+ Lead(IV) ionSn2+ Tin(II) ion Sn4+ Tin(IV) ionCr2+ Chromium(II) ion Cr3+ Chromium(III) ionCr6+ Chromium(VI) ionMn2+ Manganese(II) ion Mn3+ Manganese(III) ionCo2+ Cobalt(II) ion Co3+ Cobalt(III) ionNi2+ Nickel(II) ion Ni3+ Nickel(III) ionAg+ Silver ionZn2+ Zinc ionCd2+ Cadmium ion

Note: Silver, Zinc and Cadmium do not have more than one common oxidation number. Do not use a Roman numeral when naming them.

Symbols of Ions for AnionsAn anion is an atom or group of atoms with a negative charge.

An anion has more electrons than a neutral atom of the element.

Group 17 forms -1 ions.



The names of monatomic anions end in ide.Back to main menu

Naming and Writing Formulas for Anions

Element Symbol of Ion Name of Ion

Chlorine

Nitrogen

Oxygen

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Cl- Chloride ion

N3- Nitride ion

O2- Oxide ion

You Try It. Write the symbol and name for each of the following ions.

You Try It

Complete the following table.

S2-

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Symbol of Ion

Name of Ion Number of Electrons Lost or Gained

Sulfide ion

Cu+

Barium ion

Al3+

Iron(III) ion

Li+

Phosphide ion

2 e- gainedCopper(I) ion 1 e- lost

Ba2+ 2 e- lostAluminum ion 3 e- lost

Fe3+ 3 e- lostLithium ion 1 e- lost

P3- 3 e- gained

Naming and Predicting Formulas for Binary Ionic Compounds

Binary ionic compounds usually consist of a metal, such as an alkali metal, bonded to a nonmetal, such as a halogen.

They are electrically neutral. This means that the total positive charge is equal to the total negative charge.

Empirical formulas are used to represent ionic compounds. An empirical formula is the simplest ratio in which the atoms combine to form a compound.

They are named by naming the cation followed by the anion. ex. LiCl is lithium chloride, FeCl2 is iron(II) chloride

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Examples: Write the formulas for the compounds formed between the following pairs of ions and then name the compound.

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a. K+, Cl-

b. Mg2+, S2-

c. Na+, N3-

d. Al3+, S2-

e. Sn4+, O2-

KClMgSNa3N

Al2S3

SnO2

potassium chloride

magnesium sulfide

sodium nitride

aluminum sulfide

tin(IV) oxide

You Try ItWrite the formulas for the following binary ionic compounds. Hint: First determine the symbols for the ions involved. Always write the cation first. The first one has been done for you as an example.

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a. Sodium bromide

b. Magnesium sulfide

c. Copper(I) chloride

d. Calcium bromide

e. Strontium fluoride

Na+, Br-

Mg2+, S2-

Cu+, Cl-

Ca2+, Br-

Sr2+, F-

NaBr

MgS

CuCl

CaBr2

SrF2

You Try ItWrite the formulas for the following binary ionic compounds. Hint: First determine the symbols for the ions involved. Always write the cation first. The first one has been done for you as an example.

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f. Sodium oxide

g. Lead(II) bromide

h. Zinc sulfide

i. Aluminum oxide

j. Chromium(VI) nitride

Na+, O2-

Pb2+, Br-

Zn2+, S2-

Al3+, O2-

Cr6+, N3-

Na2O

PbBr2

ZnS

Al2O3

CrN2

Roman NumeralsSo far, you have been given examples where the Roman numeral has been indicated either by the name of the compound or by the symbol of the cation.

But how do you determine the charge of the Roman numeral if it is not given to you?

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To determine the charge of the Roman numeral you have to first identify the ions making up the compound.

Roman NumeralsExamples.

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Fe2O3 Iron(III) oxide

Ions Chemical Formula Name of Compound

Fe3+, O2-

Cu+, S2-

CoI2

Tin(IV) oxide

FeS

Cu3N

Cu2S Copper(I) sulfideCo2+, I- Cobalt(II) iodide

Sn4+, O2- SnO2

Fe2+, S2- Iron(II) sulfideCu+, N3- Copper(I) nitride

You Try ItWrite formulas for the following compounds. Remember to determine the ions involved first.

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Name of Compound Ions Formula of

Compound

Lithium oxide

Tin(IV) sulfide

Barium nitride

Sodium fluoride

Li2OLi+, O2-

Sn4+, S2- SnS2

Na+, F-

Ba2+, N3- Ba3N2

NaF

You Try ItName the following compounds.

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a. CaS

b. FeN

c. K2O

d. PbO

Calcium sulfide

Iron(III) nitride

Potassium oxide

Lead(II) oxide

Naming and Writing Formulas for Ternary Ionic Compounds

Ternary ionic compounds contain more than two elements. They usually contain one or more polyatomic ions.

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POLYATOMIC IONS

Name of Ion Symbol Name of Ion Symbol

Acetate C2H3O2-, CH3COO- Hyroxide OH-

Ammonium NH4+ Hypochlorite ClO-

Carbonate CO32- Nitrate NO3

-

Chlorate ClO3- Nitrite NO2

-

Chlorite ClO2- Perchlorate ClO4

-

Chromate CrO42- Permanganate MnO4

-

Cyanide CN- Phosphate PO43-

Dichromate Cr2O72- Sulfate SO4

2-

Hydrogen Carbonate HCO3- Sulfite SO3

2-

Note: You are expected to be able to use this list to help you determine the names/symbols of polyatomic ions not given in the list.

Predict the symbol for each of the following polyatomic ions.

Bromate ionPhosphite ion

BrO3-

PO33-

Writing the Formulas and Naming Ternary Ionic Compounds

Writing the formulas and naming ternary ionic compounds is just like writing the formula and naming binary ionic compounds.

To write the formula, you write the symbol and charge of the ions involved and then balance the charges.

To name the compound, you name the ions. Back to main menu

Naming and Writing Formulas for Ternary Ionic Compounds

Examples:

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a. K+, NO3-

b. Ba2+, PO43-

KNO3

Ba3(PO4)2

Potassium nitrate

Barium phosphate

You Try It1. Write the formulas for the following ternary

ionic compounds, given the ions involved then name the compounds.

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a. Ca2+, SO42-

b. K+, PO43-

c. NH4+, N3-

d. Fe3+, SO42-

CaSO4

K3PO4

(NH4)3N

Fe2(SO4)3

Calcium Sulfate

Potassium Phosphate

Ammonium nitride

Iron(III) sulfate

You Try It2. Write the formulas for the following

ternary ionic compounds given their names.

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Lithium hypochlorite

Sodium sulfite

Calcium acetate

Barium phosphate

Copper(II) nitrite

LiClO

Na2SO3

Ca(C2H3O2)2

Ba3(PO4)2

Cu(NO2)2

Li+, ClO-

Na+, SO32-

Ca2+, C2H3O2-

Ba2+, PO43-

Cu2+, NO2-

You Try It3. Name the following compounds.

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a. Ca(NO3)2

b. K2SO4

c. PbSO3

d. NaC2H3O2

e. (NH4)2S

Calcium nitrate

Potassium sulfate

Lead(II) sulfite

Sodium Acetate

Ammonium sulfide

Daily Starter (12/5 & 12/6)1. Name the following compounds.

a. LiClb. MgSc. Cu2Od. BaCO3

e. Fe(NO3)3

Lithium chlorideMagnesium sulfideCopper(I) oxideBarium carbonate

Iron(III) nitrate

Daily Starter (12/5 & 12/6)

2. Write the chemical formula for each of the following compounds.

a. Sodium nitride

b. Lithium phosphate

c. Tin(IV) carbonate

d. Calcium sulfide

e. Lead(II) nitrate

Na3N

Li3PO4

Sn(CO3)2

CaS

Pb(NO3)2

Metallic Bonding

Metals have some characteristics that distinguish them from nonmetals. Name some properties of metals.

Good conductors of heat and electricity

Ductile: Capable of being drawn into fine wires

Malleable: Capable of being shaped (hammered) without breaking Back to mai

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Metallic Bonding and Sea of Electrons

Metals have these properties because metal atoms form a special type of bond with each other called a metallic bond.

In metallic bonding, metal atoms don’t lose their valence electrons. The metal atoms release their valence electrons into a “sea of electrons” shared by all of the metal atoms. Back to mai

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The electrons are said to be delocalized because they are not held in one “locality” as part of a specific ion or covalent bond.

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Metallic bonding between different metals results in the formation of solutions, also called alloys.

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Explaining Metallic Properties - Hardness

The hardness of a metal is determined by the number of delocalized valence electrons.

The alkali metals are very soft metals which can be easily cut by a knife. This is due to the fact that the alkali metals only have one valence electron per atom. Back to mai

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Explaining Metallic Properties - Luster

The delocalized valence electrons interact readily with light, creating the luster of metals.

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Explaining Metallic Properties Malleability and Ductility

The delocalized valence electrons of a metal are spread more or less uniformly throughout the metal.

When a piece of metal is subjected to pressure, the positive cores of the atoms slide past each other but are still held together by the delocalized sea of electrons. Back to mai

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Why aren’t ionic compounds malleable?

If an ionic compound is struck with a hammer, the blow tends to push ions of like charge together. they repel, and the crystal shatters.

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Explaining Metallic Properties Conductivity of Metals

Because the valence electrons of all metal atoms are not attached to any one metal atom, they can move easily through the metal when an external force, such as that provided by a battery, is applied.

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Why aren’t molecular or ionic compounds good conductors?

In molecular compounds, the valence electrons are localized in electron pair bonds between neutral atoms.

In ionic compounds, the electrons are bound to individual ions that are held in place in crystal structures.

Since the electrons are not free to move throughout the solid, ionic and molecular compounds are not good conductors of heat and electricity.

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Naming Bases

Bases are compounds that produce hydroxide ions (OH-) in water.

Bases are named by naming the metallic ion and adding the word hydroxide.

Example: LiOH

Lithium hydroxide Back to main menu

You Try It

Write names for the following bases.

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a. NaOHb. KOHc. Mg(OH)2

d. CuOH

Sodium hydroxidePotassium hydroxideMagnesium hydroxideCopper(I) hydroxide

An exception is NH3. This is ammonia.

Writing Formulas for Bases

Balance the charges as you would other ionic compounds.

Example: Strontium hydroxide

Sr2+, OH-

Sr(OH)2

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You Try It

Write the formulas for the following bases.

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a. Tin(II) hydroxideb. Lithium hydroxidec. Barium hydroxided. Tin(IV) hydroxide

Sn2+, OH-

Li+, OH-

Ba2+, OH-

Sn4+, OH-

Sn(OH)2

LiOHBa(OH)2

Sn(OH)4

Naming Binary Acids (H + Nonmetal)

Acids are compounds that produce hydrogen ions (H+) in water.

Binary acids contain hydrogen and a nonmetal – they do not contain oxygen.

Binary acids are named by using the prefix hydro, then the root followed by the ic suffix.

Example: HBr

hydrobromic acid Back to main menu

You Try It

Write names for the following binary acids.

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a. HClb. HIc. H2S

Hydrochloric acidHydroiodic acidHydrosulfuric acid

Writing Formulas for Binary Acids

Balance the charges just as you did for ionic compounds.

Example: Hydrophosphoric acid

H+, P3-

H3P

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You Try It

Write the formulas for the following binary acids.

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a. Hydrofluoric acidb. Hydroselenic acid

H+, F-

H+, Se2-

HFH2Se

Naming Oxyacids (H + Polyatomic Ion)

Oxyacids contain polyatomic ions.

The name indicates the number of oxygen atoms in each molecule and the nonmetallic element present.

Suffixes and prefixes are used to indicate the number of oxygen atoms present.

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Naming Oxyacids

In order to name oxyacids, it is important to known the name of the polyatomic ion from which the acid is formed.

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Note: Not all forms of a polyatomic ion are given on your state formula chart.

Note: The common polyatomic ions for bromine and iodine, follow the same pattern as chlorine.

Example – Naming the Acids of Chlorine

Ion Name of Ion Formula of Acid Name of Acid

ClO3- chlorate

ClO2- chlorite

ClO- hypochlorite

ClO4- perchlorate

Cl- chloride

HClO3

HClO2

HClO2

HClO4

HCl

chloric acid

chlorous acid

hypochlorous acid

perchloric acid

hydrochloric acid(This is a binary acid)

Examples to be Worked Together

a. HNO3

b. H3PO3

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nitric acid (-ate ion)

phosphorous acid (-ite ion)

You Try It

a. H2SO3

b. HNO2

c. H3PO4

d. HIO2 Back to main menu

sulfurous acid

nitrous acid

phosphoric acid

Iodous acid

Name the following acids.

Writing Formulas for Oxyacids

1. Identify the polyatomic ion

2. Balance the charges just as you did for ionic compounds.

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Example: Carbonic Acid-ic comes from ateCarbonate is CO3

2- H+, CO3

2- H2CO3

You Try It

Write the formulas for the following acids.

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a. Bromous acidb. Periodic acidc. Carbonous acidd. Acetic Acid

H+, BrO2-

H+, IO4-

H+, CO22-

H+, C2H3O2-

HBrO2

HIO4

H2CO2

HC2H3O2

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IONIC BONDING AND NOMENCLATURE. Ionic Bonding and Nomenclature Ionic Bonding Comparing the Properties of Ionic and Covalent Compounds Naming and Writing