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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

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3416

Why do Atoms Form Compounds?

•Stability.•What makes an atom stable?

•Full outer energy level.•Eight.•Chart page 576.

3

•A Chemical Bond holds atoms together in a compound.

•Two basic typesTwo basic types:

•Ionic•Covalent

4

Ionic Bonding

Transfer of

electrons

from one

atom to

another

atom.

Occurs between

metals and nonmetals.

Remember: Atoms need a full outer energy level to be

stable.

EIGHT!

5

Occurs between metals and nonmetals.

Metals are electron donors.

Non-metals are electron accepters.

Called compounds.

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7

OPPOSITES ATTRACT!

8

Ionic

Bondin

g

CLIP

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Covalent Bonding

The

sharing of

electrons

between

atoms.

Occurs between nonmetal

s and nonmetal

s.Called

Molecules.

10

11

Hydrogen and Fluorine

Hydrogen and Chlorine

12

Single, Double, Triple

13

Clip

14

Unequal Sharing

δ+

Polar

δ_

When one

atom has a

greater positive charge

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1.CO2

2.H2O

3.NaCl4.MgCl2

5.NO2

6.H2SO4

7.NaF

9.NaPO4

10.HCl11.NaF12.KCl13.CaCO3

14.N2

15.Cl2

clip

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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? 

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The simplest compounds are ones

with only two elements

These are called binary

KI, CO, H2O, NaCl

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+1

+2

-1-2

-3+3

+4 -4 0Oxidation numbers

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

stable.

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!

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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.

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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

Elements22

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.Fe+2 + O10.Fe+3 + O11.Cu+2 + F12.Cr+3 + O13.Mg + O14.Al + P

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.

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Try these…….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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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 Check to see if any elements are any elements are multivalent.multivalent.

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

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

Examples:1.NaCl2.K2O

3.AlCl34.BaF2

5.KI6.Li2O

If ionic …….2. Check to see if any

elements are multivalent.

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

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

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

Examples:

1.FeO2.Fe2O3

3.CuO4.Cu2O

5.PbCl4

6.PbI2

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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

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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

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Name the following:

1.KBr2.HCl3.MgO4.CaCl5.H2O

6.NO2

7.CuSO4

8.CaSO4

9.NH4OH

10.CaCO3

11.Cu(ClO3) 2

12.Cr2O 3

13.SrI 2

14.CCl4

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Goals revisited

Chemical Reactions• A chemical reaction is a change in

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

molecules.

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

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Chemical equations are a shorthand way to show

chemical reactions.

Reactants Products

H2 + O2 H2O

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Conservation of Mass

The mass of the

products always

equals the mass

of the reactants

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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.

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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.

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40

1.Synthesis2.Decomposition

3.Single Replacement (Single Displacement)

4.Double Replacement (Double Displacement)

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Synthesis“to make”

A + B AB

Cu + O CuO

2H2 + O2 2H2O

Decomposition“to breakdown”

2H2O 2H2 + O2

AB A + B

NaOH Na + OH

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+K2SO4 BaSO4 2KNO3

Clip

Clip

Chemical Reactions and Energy

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

• Chemical reactions are the making and breaking or bonds.

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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…..