1

Adventures of Oxygen Clip

1. Compare & contrast ionic and covalent bonds in terms of electron position.

2. Predict formulas for stable binary ionic compounds based on balance of charges.

3. Use IUPAC nomenclature for transition between chemical names and chemical formulas of - binary ionic compounds - binary covalent compounds

4. Apply the Law of Conservation of Matter by balancing the following types of chemical

equations:• Synthesis

• Decomposition• Single Replacement• Double Replacement

GOALGOALSS

2

3416

3. Determine the Types of ions formed by representative elements

Why do Atoms Form Compounds?•Stability.•What makes an atom stable?•Full outer energy level.

–Eight.

•They can either……–1) Gain electrons–2) Lose electrons–3) Share electrons

3

•A Chemical Bond holds atoms together in a compound.

•Two basic typesTwo basic types:

1. Ionic2. Covalent

4

Ionic Bonding

TransferTransfer of

electrons

from one

atom to

another

atom.

Occurs between metals &

nonmetals.

Remember: Atoms need a full outer energy level to be stable. EIGHT!

5

Called compounds.

Occurs between metals and nonmetals.

Metals are electron donors.

SO, they become POSITIVE

Non-metals are electron accepters.

SO, they become NEGATIVE.

6 Ionic Bonding

OPPOSITS ATTRACT!

When Atoms gain or lose When Atoms gain or lose electrons, they are called electrons, they are called Ions.Ions.

Cation

Anion

3P

3P3P

3P

3P

3P

7

• Metals lose electrons to become stable.

• Nonmetals gain electrons to become stable.

8

Atoms can gain or lose electronsAtoms can gain or lose electrons

Ionization: requires energy

Why do atoms lose and gain electrons?

To become more stable.

Stability=full outer energy level

9

OPPOSITS ATTRACT!

11

Properties of Ionic Compounds

• Crystalline solids at room temperature.

• Arranged in repeating three-dimensional patterns

• Have high melting points• Can conduct electricity

when melted or dissolved in water

12

Ionic

Bondin

g

CLIP

13

Covalent Bonding

The

sharing of

electrons

between

atoms.

Occurs between nonmetal

s and nonmetal

s.Called Molecules.

14

15

Hydrogen and Fluorine

Hydrogen and Chlorine

16

17 Single, Double,

Triple 2 e- 4e- 6e-

Clip

18

Unequal Sharing

δ+

Called Polarδ_

19

Polar molecules

happen when one

atom has a greater positive charge

Properties of Covalent Molecules

• Many are gases or liquids at room temperature

• Composed of two nonmetals.

• Have low melting and boiling points

20

• Ionic and Covalent Bonding Review Clip

1.CO2

2.NaCl3.H2O

4.MgCl2

5.NO2

6.Li2S

7.NaF

9.BeO 10.HCl11.NaF12.KCl13.H2O2

14.N2

15.Cl2

clip

21 Covalent or Ionic?(write the formula, then write “C” or “I”

Goals revisited

•Writing chemical formulas is a shorthand way of indicating what a substance is made of.  •These formulas also let you know how many atoms of each type are found in a molecule.  The chemical formula for water is H2O.  Carbon Dioxide is CO2.  Why does oxygen combine in different ratios, in different compounds?  The chemical formula for table salt is NaCl. Calcium Chloride is CaCl2.

Why does chlorine combine in different ratios, in different compounds? 

22

The simplest compounds are ones

with only two elements

These are called binary

KI, CO, H2O, NaCl

23

+1

+2

-1

-2

-3

+3

+4 -4

0Oxidation numbers

Tell you how many electrons an atom must gain, lose or share to become

stable.24

We can predict the ratio of atoms in ionic compounds based on

their oxidation numbers

Oxidation numbers

K Cl+1

-1

KClTells you how many electrons an atom must gain, lose or share to become

stable.

1 valence electron

7 valence electronAll All

compounds compounds are neutralare neutralThat means the That means the

overall charge is overall charge is

ZERO!ZERO!

25

Subscripts show the number of atoms of that kind in the compound

Na

Br

+1

-1

NaBr

Ca Br

+2

-1

CaBr2

To make it ZERO, you

need 1 Ca & 2 Br.

26

Now You Try writing Binary Ionic formulas

1.K + Br2.Mg + Cl3.Ca + I4.K + O5.K + I6.Sr + Br7.Na + O

8.Ga + Br9.Mg + O10.Al + P

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Some elements have more than one oxidation number (Chart p588)

Fe O

+3

-2

Fe2O

3

Fe O

+2

-2

FeOWe call these elements- Multivalent

Elements28

Multivalent Practice

1. Fe+2 + O2. Fe+3 + O3. Cu+2 + F4. Cr+3 + O

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Cations: ammonium, NH4+

Anions: nitrate, NO3-

sulfate, SO42-

hydroxide, OH-

phosphate, PO43-

carbonate, CO32-

chlorate, ClO3-

permanganate, MnO4-

chromate, CrO42-

Polyatomic Ions

Groups of Covalently Bonded

atoms that stay

together.

30

Try these……p591

1.Na + SO4

2.Mg + PO4

3.Ca + CO3

4.Na + OH5.Mg + OH6.NH4 + OH

7.K + PO4

8.NH4 + NO3

9.H + SO4

10.Ca + SO4

11.K + NO3

12. Na + PO4

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Mixed Practice

Naming Binary Compounds and Molecules

• Steps:– If it is Binary-1. Decide if it is an ionic or covalent

bond.– Metal- nonmetal…..

» Ionic– Nonmetal- nonmetal….

» Covalent

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Example:• NaCl

If ionic …….

2.2. Check to see if any Check to see if any elements are elements are multivalent or multivalent or polyatomic.polyatomic.

3.3. If all single valentIf all single valent, , write the name of write the name of the positive ion the positive ion first.first.

4.4. Write the root of the Write the root of the negative ion and negative ion and add –ide.add –ide.

Examples:1.NaCl2.K2O

3.AlCl34.BaF2

5.KI6.Li2O

33

If ionic …….5. Check to see if any

elements are multivalent.

6. If multivalent ions, determine the oxidation number of the element.

7. Use Roman numerals in parentheses after the name of the element.

8. Write the root of the negative ion and add –ide.

Examples:

1.FeO2.Fe2O3

3.CuO4.Cu2O

5.PbCl4

6.PbI2

34

If it contains a polyatomic ion...2. Write the name

of the positive ion.

3. Write the name of the polyatomic ion.

Examples:1. NaCO3

2. KNO3

3. NaC2H3O2

Example:•KOH

•Potassium Hydroxide•CaCO3

•Calcium Carbonate

35

If Covalent...2. Use Greek prefix to

indicate how many atoms of each element are in the molecule

3. Add -ide to the more electronegative element

Greek Prefixes1- mono-2- di-3- tri-4- tetra-5- penta-6- hexa-7- hepta-8- octa-

Example:•NO

•Nitrogen Monoxide•PCl3

•Phosphorous trichloride

36

Name the following:Mixed Practice

1.KBr2.HCl3.MgO4.CaCl25.H2O

6.NO2

7.CuSO4

8.CaSO4

9.NH4OH

10.CaCO3

11.Cu(ClO3) 2

12.Cr2O 3

13. FeO

14. LiBr15 MgCl

37

38

Goals revisited

Chemical Reactions• A chemical reaction is a change in A chemical reaction is a change in

which one or more substances are which one or more substances are converted into new substances.converted into new substances.– Rearrangement of bonds in compounds and Rearrangement of bonds in compounds and

molecules.molecules.

• Chemical Equations make it possible to see clearly what is happening during a chemical reaction

39

Chemical equations are a shorthand way to show

chemical reactions.

Reactants Products

H2 + O2 H2O

40

Conservation of Mass

The mass of the

products always

equals the mass

of the reactants

41

H2 + O2 H2O

2 Hydrogen atoms

2 Oxygen atoms

2 Hydrogen atoms & one Oxygen atom

Does this meet the Conservation of Mass

Law?

Must Balance the Equation to show Conservation of

Mass.

42

2

H2 + O2 H2O2

4 1 2 2

2

4

Balanced!!

Can add coefficients to Balance equations.

Steps:

1. Count Atoms on both sides2. If not Balanced, add coefficients to

balance.3. Recount atoms after adding each coefficient.

2

4. Keep adding coefficients until balanced.

43

44

45 Chemical Reactions

• You start with one or more compounds and turn it into different compounds.

Vapors of hydrogen chloride in a beaker and ammonia in a test tube meet to form a cloud of a new substance, ammonium chloride.

1.Synthesis2.Decomposition

3.Single Replacement (Single Displacement)

4.Double Replacement (Double Displacement)

46

Synthesis“to make”

A + B AB

Cu + O CuO

2H2 + O2 2H2O

Decomposition“to breakdown”

2H2O 2H2 + O2

AB A + B

NaOH Na + OH

Animation

Single ReplacementWhen one element replaces another

element in a compound

A + BC AC + BCu+AgNO3 Cu(NO3)2+

2Ag

The more reactive metal will always replace the less reactive

metal. (p749)

• Clip

Single Replacement

Double ReplacementPositive Ion of One compound replaces the positive ion of another compound

and a Precipitate is formed.

AB + CD AD + CBBa(NO3)2+KSO4 2KNO3 + BaSO4

Review Clip

ClipAnimation

Review Clip

Chemical Reactions and Energy

• All chemical reactions release or absorb energy.– Heat, light, sound

• Chemical reactions are the making and breaking or bonds.

51

1. Exergonic

• Chemical reactions that releases energy are called exergonic.– Glow sticks

• If heat is released, it is called exothermic.

2. Endergonic

• Chemical reactions that require energy are called endergonic.

• Ex: Cold Packs• If heat is absorbed, it is called

endothermic

Catalysts and InhibitorsSome reactions proceed slowly.

•They can be sped up by a catalysts.– Catalysts are not used up in the reaction.– EX: enzymes (biological catalysts)

Some reactions proceed too fast.•They can be slowed down by

inhibitors.– EX: Preservatives in food

1. Compare & contrast ionic and covalent bonds in terms of electron position.

2. Predict formulas for stable binary ionic compounds based on balance of charges.

3. Use IUPAC nomenclature for transition between chemical names and chemical formulas of• binary ionic compounds • binary covalent compounds

4. Apply the Law of Conservation of Matter by balancing the following types of chemical

equations:• Synthesis

• Decomposition• Single Replacement• Double Replacement

GOALS GOALS Revisited…..Revisited…..