Chemistry Chapter 7 Chemical Formulas and Chemical Compounds.

Chemistry Chapter 7Chemistry Chapter 7

Chemical Formulas and

Chemical Compounds

Elements combine to form bonds

Covalent Bonds

-Electrons are shared-Usually between two

non-metals

EXAMPLE: carbon dioxide

Ionic Bonds

-Electrons are transferred

-Usually between a metal and a non-metal or polyatomic ions

EXAMPLE: sodium chloride

Different systems of naming depending on the type of bond…BE CAREFUL!

IonsIonsIonsIons• Cation:Cation: A positive ion A positive ion

• MgMg2+2+, NH, NH44++

• Anion:Anion: A negative ionA negative ion • ClCl--, SO, SO44

2-2-

• Ionic Bonding:Ionic Bonding: Force of attraction Force of attraction between oppositely charged ions.between oppositely charged ions.

Predicting Ionic ChargesPredicting Ionic Charges

Group 1Group 1:: Lose 1 electron to formLose 1 electron to form 1+1+ ionsions

HH++ LiLi++ NaNa++ KK++

Na

How many valence electrons does Na have?Does Na satisfy the octet rule?

Bohr Model of Sodium

How can we satisfy the octet rule?Now does Na satisfy the octet rule?

How many protons does Na have?

Protons: 11

How many electrons does Na have?

Electrons: 11

What’s the net charge on Na?

× +1 = 11

× -1 = -11

0Now, how many electrons does Na have?

Electrons: 10 × -1 = -10

+1

+

Predicting Ionic Charges

Group 2Group 2::Loses 2 electrons to formLoses 2 electrons to form 2+2+ ionsions

BeBe2+2+ MgMg2+2+ CaCa2+2+ SrSr2+2+ BaBa2+2+

Mg

Bohr Model of Magnesium

How many valence electrons does Mg have?Does Mg satisfy the octet rule?How can we satisfy the octet rule?Now does Mg satisfy the octet rule?

What is the net charge of Mg?

Protons: 12 × +1 = 12

× -1 = -10Electrons: 10

+2

+2

Predicting Ionic ChargesPredicting Ionic ChargesGroup 13Group 13:: Loses 3 Loses 3

electrons to form electrons to form 3+ ions3+ ions

BB3+3+ AlAl3+3+ GaGa3+3+

Al

Bohr Model of Aluminum

How many valence electrons does Al have?Does Al satisfy the octet rule?How can we satisfy the octet rule?Now does Al satisfy the octet rule?

What is the net charge of Al?

Protons: 13 × +1 = 13

× -1 = -10Electrons: 10

+3

+3

Predicting Ionic ChargesGroup 14: Lose 4 electrons or

gain 4 electrons?Neither! Group 14 elements rarely form ions.

Predicting Ionic ChargesPredicting Ionic ChargesGroup 15Group 15:: Gains 3 electrons Gains 3 electrons

to formto form 3-3- ionsions

NN3-3-

PP3-3-

AsAs3-3-

Nitride

Phosphide

Arsenide

P

Bohr Model of Phosphorous

How many valence electrons does P have?Does P satisfy the octet rule?How can we satisfy the octet rule?Now does P satisfy the octet rule?

What is the net charge of P?

Protons: 15 × +1 = 15

× -1 = -18Electrons: 18

-3

-3

Predicting Ionic ChargesGroup 16: Gains 2 electrons

to form 2- ions

O2-

S2-

Se2-

Oxide

Sulfide

Selenide

S

Bohr Model of Sulfur

How many valence electrons does S have?Does S satisfy the octet rule?How can we satisfy the octet rule?Now does S satisfy the octet rule?

What is the net charge of S?

Protons: 16 × +1 = 16

× -1 = -18Electrons: 18

-2

-2

Predicting Ionic ChargesPredicting Ionic ChargesGroup 17Group 17:: Gains 1 electron Gains 1 electron

to formto form 1-1- ionsions

FF1-1-

ClCl1-1-

BrBr1-1-Fluoride

Chloride

Bromide

II1-1- Iodide

Cl

Bohr Model of Chlorine

How many valence electrons does Cl have?Does Cl satisfy the octet rule?How can we satisfy the octet rule?Now does Cl satisfy the octet rule?

What is the net charge of Cl?

Protons: 17 × +1 = 17

× -1 = -18Electrons: 18

-1

-1

Predicting Ionic ChargesPredicting Ionic ChargesGroup 18Group 18:: Stable Noble gasesStable Noble gases

do notdo not form ions!form ions!

Pause for a Cause #1

What is the oxidation number of each of the following elements?

BaAlSBrNFK

Predicting Ionic ChargesGroups 3 - 12Groups 3 - 12:: Many Many transitiontransition elements have more elements have more

than one possible oxidation state.than one possible oxidation state.

Iron (II) = Fe2+ Iron (III) = Fe3+

Predicting Ionic ChargesPredicting Ionic ChargesGroups 3 - 12Groups 3 - 12:: SomeSome transitiontransition elements have only one elements have only one

possible oxidation state.possible oxidation state.

Zinc = Zn2+ Silver = Ag+ Cadmium = Cd2+

MemorizeMemorize

Polyvalent Elements and Their Chargesto Memorize

Copper

Polyvalent Element Symbol Charge

Cu +1,+2

Lead Pb +2,+4

Iron Fe +2,+3

Mercury Hg,Hg2 +1,+2

Tin Sn +2,+4

Chromium Cr +2,+3

Cobalt

Nickel

Co

NiManganese Mn

+2,+3

+2,+3+2,+3

Polyatomic Ions to Memorize!+1 -1 -2

Ammonium NH4 +1 Acetate C2H3O2 -1Bromate BrO3 -1Chlorate ClO3 -1Chlorite ClO2 -1Cyanide CN -1Bicarbonate HCO3 -1Hydroxide OH -1Nitrate NO3 -1Nitrite NO2 -1Iodate IO3 -1Permanganate MnO4

Hydrogen Sulfate HSO4

Carbonate CO3 -2Chromate CrO4 -2Dichromate Cr2O7 -2Oxalate C2O4 -2Peroxide O2 -2Sulfate SO4 -2Sulfite SO3 -2

Arsenate AsO4 -3Phosphate PO4 -3

-3

Hand out Table

Writing Ionic Compound FormulasWriting Ionic Compound Formulas

Example: Barium nitrate

1. Write the formulas for the cation and anion, including CHARGES!

BaBa NONO33

2. Check to see if charges are balanced. (If so, skip to step 5)

3. Balance charges , if necessary, using subscripts. A. Cross over the charges by using the absolute value of each ion’s charge as the subscript for the other ion. B. Use parentheses if you need more than one of a

polyatomic ion.

Not balanced!

(( )) 224. Check the subscripts and divide them by their largest common factor to give the smallest possible whole-number ratio.

5. Write the formula without the charges.

2+ -Ba(NO3)2


Example: Ammonium sulfate


2. Check to see if charges are balanced. (If so, skip to step 5)3. Balance charges , if necessary, using

subscripts. A. Cross over the charges by using the absolute value of each ion’s charge as the subscript for the other ion. B. Use parentheses if you need more than

one of a polyatomic ion. 4. Check the subscripts and divide them by their largest common factor to give the smallest possible whole-number ratio.5. Write the formula without the charges.

NHNH44 SOSO44

Not balanced!

( )( )22

+ 2-(NH4)2SO4

Let’s Practice

1. potassium nitrate2. sodium sulfate3. calcium hydroxide4. ammonium sulfite5. calcium phosphate6. aluminum chromate7. lithium bromide8. sodium peroxide

Pause for a Cause #2Page 251

16. Write formulas for each of the following compounds:

a. sodium fluoride

b. calcium oxide

c. potassium sulfide

d. magnesium chloride

e. aluminum bromide

f. lithium nitride

Writing Ionic Compound Formulas

Example: Copper II carbonate




Cu2+ CO32-

They are balanced!

CuCO3


Example: Iron (III) chloride



3. Balance charges , if necessary, using subscripts. A. Cross over the charges by using the absolute value of each ion’s charge as the subscript for the other ion. B. Use parentheses if you need more than one of a

polyatomic ion.

4. Check the subscripts and divide them by their largest common factor to give the smallest possible whole-number ratio.


FeFe ClCl

Not balanced!

33

3+ -FeCl3

Names ending in –ide usually, but not always, represent an element from the

periodic table.

Writing Ionic Compound Formulas

Example: Chromium III sulfide


2. Check to see if charges are balanced. (If so, skip to step 5)3. Balance charges , if necessary, using

subscripts. A. Cross over the charges by using the absolute value of each ion’s charge as the subscript for the other ion. B. Use parentheses if you need more than

one of a polyatomic ion. 4. Check the subscripts and divide them by their largest common factor to give the smallest possible whole-number ratio.5. Write the formula without the charges.

Cr S

Not balanced!

3

3+ 2-Cr2S32

Write formulas for each of the following compounds.

1. Chromium III hydroxide2. Mercury I chloride3. Tin IV chloride4. Iron II chromate5. Cobalt II sulfide6. Copper I sulfate7. Iron III oxide

Let’s Practice

Pause for a Cause #3Writing Formulas of Compounds that have Roman Numerals

Write the formulas for the following compounds: Lead II nitrate Iron II Sulfite Mercury I Chloride Tin II Chlorate Chromium III Dichromate Mercury II Phosphate Cobalt II Acetate

Naming Covalent Binary CompoundsNaming Covalent Binary Compounds Naming Covalent Binary CompoundsNaming Covalent Binary Compounds

• -- Compounds between twoCompounds between two nonmetalsnonmetals • -- First element First element in the formula isin the formula is named firstnamed first.. • -- Second element Second element is named as if it were anis named as if it were an

anionanion.. • -- Use prefixes Use prefixes • -- Only useOnly use monomono on second element - on second element -

PP22OO55 = =

COCO22 = =

CO =CO =

NN22O =O =

didiphosphorusphosphorus pentpentoxideoxide

carbon carbon didioxideoxide

carboncarbon monmonoxideoxidedidinitrogennitrogen monmonoxideoxide

1 – mono2 – di3 – tri4 – tetra5 - penta

6 – hexa7 – hepta8 – octa9 – nona10 – deca

If given the formula……..

• 1st determine if the compound is a binary (molecular) compound– If all the elements in the compound are non-metals

or metalloids the compound is a binary compound.– Use prefixes to name the compound.– CHARGES DON’T MATTER, DON’T WRITE

CHARGES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

– DON’T SWITCH THE PREFIXES!!!!!!!!!!!!!!!!!!!!

Pause for a Cause #4Write the formula of the following compounds(WRITE WHAT YOU SEE DO NOT CHECK OXIDATION STATE!)

a. Phosphorus Pentachloride

b. Carbon Tetrafluoride

c. Dinitrogen Pentaoxide

d. Tetraphosphorous Decaoxide

e. Carbon Monoxide

f. Carbon Disulfide

Sourvelis’s Rules For NamingLook at the first element in the compound.

If the first element is…

1. A group 1 or 2 metal, or if it is Ag, Zn, Al, Cd, simply name the compound. NaCl Sodium Chloride

2. A transitional metal all the way to the left of the metalloid line, use roman numerals. Fe2O3 Iron (III) Oxide

3. A metalloid or nonmetal use prefixes.

N2O5 Dinotrogen Pentoxide

4. is hydrogen name it like an acid. HCl Hydrochloric acid. Exception Acetic acid C2H3O2H

5. a carbon atom, name it as an organic molecule.

ex. C2H6 ethane

Mixed Review Sheet

Naming Ionic Compounds Using Rule 1Naming Ionic Compounds Using Rule 1Naming Ionic Compounds Using Rule 1Naming Ionic Compounds Using Rule 1• 1. 1. Cation first, then anionCation first, then anion

• 2. Monatomic cation = name of the element 2. Monatomic cation = name of the element • CaCa2+2+ = calcium= calcium ionion

• 3. Monatomic anion =3. Monatomic anion = rootroot ++ -ide-ide • ClCl-- = = chlorchlorideide

• CaClCaCl22 = calcium = calcium chlorchlorideide

4. For polyatomic ions, use the name of that polyatomic ion.

Let’s Practice!! Name the following compounds:

• MgCl2

• Ag2O

• Ca(OH)2

• SrS• KClO3

• NH4OH

• KClO2

• Magnesium Chloride• Silver Oxide• Calcium Hydroxide• Strontium Sulfide• Potassium Chlorate• Ammonium Hydroxide• Potassium Chlorite

Pause for a Cause #5 Name the following compounds:

K2CrO4

Ca(MnO4)2

Zn(HCO3)2

Mg3N2

Na2O2

Ba3(PO4)2

AgCl

If given the formula……..• And the compound is not a

binary compound, name the compound like an ionic compound.– Use roman numerals if the

first element is a transitional element or to the left of the metalloid line.

(Exceptions Ag, Zn, Cd)

Naming Ionic CompoundsUsing Roman Numerals

Naming Ionic CompoundsUsing Roman Numerals

Example:

• PbCl2

• Lead can be a Pb2+ or Pb4+ cation

• PbCl2 = lead (II) chloride

How do you know???

Some metals have multiple oxidation states (Groups 3-12 and to the left of the metalloid line)

How do we know that lead was +2?

PbCl2

What is the charge of chlorine ion?

-1

How many chlorine ions does PbCl2 have?

What’s the total charge of the chlorine ions?

-2

Compounds are neutral, so what must the charge of lead be in order to balance the -2 charge of chlorine?

+2The oxidation number of lead is

+2.

Let’s try Fe2O3

What is the charge of oxygen ion?

How many oxygen ions does Fe2O3 have?

What’s the total charge of the oxygen ions?

What must the charge of iron be in order to balance the -6 charge of the oxygens?

Fe O2 3

-2

-6+6

+3

Iron III OxideThe oxidation

number of iron is +3.

Let’s practice!!! Name the following compounds:• CuO• CoF3

• SnI4

• FeS

Copper II OxideCobalt III FluorideTin IV IodideIron II Sulfide

If given the name…..• If the compound is not a binary compound

(contains polyatomic ions), use the rules for writing ionic compounds.– Make sure to use the correct charges.– Make sure you don’t change the subscripts of the

polyatomic ions.– THE ANSWER DOES NOT HAVE ANY

CHARGES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Name the following compounds:

Pb(ClO3)2

Co2O3

Fe2(Cr2O7)3

NiBr2

MnSO4

SnOHg2Cl2

Fe(HCO3)3

Pause for a Cause #6

If given the name…..• 1st check for prefixes.

– If prefixes are present, the compound is probably a binary compound.

– DON’T WORRY ABOUT CHARGES, DON’T WRITE CHARGES, JUST WRITE WHAT YOU SEE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

– ***Remember some polyatomic ions have prefixes (bicarbonate, dichromate, dimercury). Write these like ionic compounds.

Pause for a Cause #7Name the following compounds using prefixes:

OF2

SiO2

SO3

P2O5

BF3

XeF4

Quiz: Name the formulaAgC2H3O2

FeCl3N2O4

Cr2O3

FeCl2

Quiz: Write the Formulasulfur tetrachlorideammonium carbonatechromium (III) oxidesodium peroxideAntimony (III) Chloride

Acid Nomenclature• AcidsAcids

– Compounds that form HCompounds that form H++ in water. in water.

– Formulas usually begin with ‘H’.Formulas usually begin with ‘H’.

– Exception is acetic acid CHException is acetic acid CH33C00C00HH

• Examples:Examples:

– HCl HCl (aq)(aq) – hydrochloric acid – hydrochloric acid

– HNOHNO33 – nitric acid – nitric acid

– HH22SOSO44 – sulfuric acid – sulfuric acid

Anion Ending Acid Name

-ide hydro-(stem)-ic acid

-ate (stem)-ic acid

-ite (stem)-ous acid

Acid Nomenclature

Binary Binary

Ternary Ternary

An easy way to remember which goes with which…An easy way to remember which goes with which…

““In the cafeteria, you In the cafeteria, you ATEATE something something ICICky”ky”

Acid Nomenclature Flowchart

h yd ro - p re fix-ic en d in g

2 e lem en ts

-a te en d in gb ecom es-ic en d in g

-ite en d in gb ecom es

-o u s en d in g

n o h yd ro - p re fix

3 e lem en ts

AC ID Ss ta rt w ith 'H '

• HBr HBr (aq)(aq)

• HH22COCO33

• HH22SOSO33

• 2 elements, 2 elements, --ideide

• 3 elements, 3 elements, -ate-ate

• 3 elements, 3 elements, -ite-ite

hydrohydrobromic acidbromic acid

carboncarbonicic acid acid

sulfursulfurousous acid acid

Acid Nomenclature

• hydrofluoric acidhydrofluoric acid

• sulfuric acidsulfuric acid

• nitrous acidnitrous acid

• 2 elements2 elements

• 3 elements, 3 elements, -ic-ic

• 3 elements, 3 elements, -ous-ous

HF HF (aq)(aq)

HH22SOSO44

HNOHNO22

Acid Nomenclature

HH++ F- F-

HH++ SO SO442-2-

HH++ NO NO22--

Binary Acids

HF(aq) - HCl(aq) -HBr(aq) - HI(aq) - H2S(aq) -

hydrofluoric acidhydrochloric acidhydrobromic acidhydriodic acidhydrosulfuric acid

Exception, HI the “o” in hydro is left off for HI(aq), so its name is hydriodic acid.HCl(aq) HCl(gas)

Name ‘Em!• HH22SOSO33

• HNOHNO33

• H3PO4

• CH3COOH

sulfurous acidnitric acidphosphoric acidacetic acid

Write the Formula!

• Hydrobromic acidHydrobromic acid

• Nitrous acidNitrous acid

• Carbonic acidCarbonic acid

• Phosphoric acidPhosphoric acid

HBr

HNO2

H2CO3

H3PO4

• Straight Chains– Hydrocarbons linked in a straight chain

• C8H18

• Cyclochains– Hydrocarbon interlinked in a ring structure

• C6H12

Hydrocarbons - molecules that possess hydrogen and carbon

Alkanes – hydrocarbons with only C-C single bonds.

Example: Butane CH3CH2CH2CH3 C4H10 CnH2n+2

Alkenes – hydrocarbons with C=C double bonds.

Example: Butene CH3CH=CHCH3 C4H8 CnH2n

Alkynes – hydrocarbons with C C triple bonds.

Example: Butyne CH3C CCH3 C4H6 CnH2n-2

Alcohols – R-OH (-OH is hydroxyl group, NOT hydroxide)

Example: CH3OH Methanol

Basic Naming of HydrocarbonsHydrocarbon names are based on: 1) type,

2) # of carbons, 3) side chain type and position 1) name will end in -ane, -ene, or -yne2) the number of carbons is given by a “prefix”

1 meth- 2 eth- 3 prop- 4 but- 5 pent- 6 hex- 7 hept- 8 oct- 9 non- 10 dec-

Actually, all end in a, but a is dropped when next to a vowel. E.g. a 6 C alkene is hexene

Q - What names would be given to these:7C, 9C alkane2C, 4C alkyne1C, 3C alkene

heptane, nonaneethyne, butynemethene, propene

Mnemonic for First Four Prefixes

First four prefixes• Meth-

• Eth-

• Prop-

• But-

MonkeysEatPeeledBananas

?Decade

Decimal

Decathalon

Other Prefixes

PentHexHepOctNonDec

Organic Compounds Containing Oxygen

• An alcohol is a compound obtained by substituting a hydroxyl group (-OH) for an –H atom on a carbon atom of a hydrocarbon group.• Some examples are

CH3 OH CH2CH3 OH CH3CHCH3

OH

methanol ethanol propanol

Practice-Give the name or formula

a. Butane

b. Pentene

c. Methanold. C2H4

e. C7H15OH

• 1, 3, 5-Cyclohexene

• Cyclopentane

Chemistry Chapter 7 Chemical Formulas and Chemical Compounds.

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