How are the following words How are the following words related?related?

ouroouro

zlatozlato

de orode oro

aurumaurum

• All are the word for the element “gold” All are the word for the element “gold” in Portuguese, Croatian, Spanish, and in Portuguese, Croatian, Spanish, and LatinLatin

CHAPTER 9p. 252

CHEMICAL NAMES AND FORMULAS

SECTION 9.1 p. 253SECTION 9.1 p. 253NAMING IONSNAMING IONS

•Atoms - neutral

•same # + and e-•Ions are atoms, or groups of atoms, with a charge (positive or negative)

•different # + and e-•gain or lose e-’s•Monotomic IonsMonotomic Ions – 1 atom w/ + or - charge

A Cation is…A Cation is… + ion formed by losing e-’s Metals lose e-’s Charge written as superscript

K1+ Has lost one electron (no name change for positive ions)

Ca2+ Has lost two electrons

An Anion is…An Anion is…• - ion•gains e-’s•Nonmetals can gain e-’s

Ion High School

Predicting Ionic ChargesGroupGroup 1A1A:: Lose 1 e- to form 1+ ionsLose 1 e- to form 1+ ions

HH1+1+ LiLi1+1+ NaNa1+1+ KK1+1+ RbRb1+1+

Predicting Ionic ChargesGroup 2AGroup 2A:: Loses 2 e-’s to form 2+ ionsLoses 2 e-’s to form 2+ ions

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

Predicting Ionic ChargesGroup 3AGroup 3A:: Loses 3 Loses 3

e-’s to form e-’s to form 3+ ions3+ ions

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

Predicting Ionic ChargesGroup 4AGroup 4A:: Do they Do they

loselose 4 e-’s or 4 e-’s or gaingain 4 4 e-’s?e-’s?

Neither! Group 4A Neither! Group 4A elements rarely form elements rarely form ions ions (they tend to share)(they tend to share)

Predicting Ionic ChargesGroup 5AGroup 5A:: Gains 3 Gains 3

e-’s to form e-’s to form 3- ions3- ions

NN3-3-

PP3-3-

AsAs3-3-

Nitride

Phosphide

Arsenide

Predicting Ionic Charges

Group 6AGroup 6A:: Gains 2 Gains 2 e-’s to form e-’s to form 2- ions2- ions

OO2-2-

SS2-2-

SeSe2-2-

Oxide

Sulfide

Selenide

Predicting Ionic ChargesGroup 7AGroup 7A:: Gains 1 Gains 1

e- to form e- to form 1- ions1- ions

FF1-1-

ClCl1-1-

BrBr1-1-Fluoride

Chloride

Bromide

II1-1- Iodide

Predicting Ionic ChargesGroup 8AGroup 8A:: Stable Stable

noble gases noble gases do notdo not form ions!form ions!

Predicting Ionic ChargesGroup B elementsGroup B elements:: Many transition elements Many transition elements

have have more than onemore than one possible oxidation state. possible oxidation state.Iron (II) = Fe2+

Iron (III) = Fe3+Roman numerals show charges

Naming cations

1) Stock system – Roman numerals in () indicates numerical value

2) Classical method – root word w/ suffixes (-ous, -ic)• Doesn’t give true value

Naming cations•Stock system.•Cation - if the charge is always the same (like in the Group A metals) just write the name of the metal.

•Transition metals can have more than one charge.• Indicate their charge as Roman numeral in () after name of cation (Table 9.2, p.255)

Predicting Ionic Charges Some of the Some of the post-transitionpost-transition elements also elements also have have more than onemore than one possible oxidation state. possible oxidation state.Tin (II) = Sn2+ Lead (II) = Pb2+

Tin (IV) = Sn4+ Lead (IV) = Pb 4+

Predicting Ionic ChargesGroup B elementsGroup B elements:: Some transition elements Some transition elements

have have only oneonly one possible oxidation state, such possible oxidation state, such as these three:as these three:

Zinc = Zn2+Silver = Ag1+ Cadmium = Cd2+

Exceptions:•Some transition metals have only one ionic charge:

•Do not use Roman numerals for these:

•Silver always 1+ (Ag1+)•Cadmium and Zinc always 2+ (Cd2+ and Zn2+)

Practice by naming these:

•Na1+ •Ca2+ •Al3+ •Fe3+ •Pb2+ •Li1+

Write symbols for these:

•Potassium ion•Magnesium ion •Copper (II) ion•Chromium (VI) ion•Barium ion•Mercury (II) ion

Naming Anions

•Change monatomic element ending to – ide

•F1- a Fluorine atom becomes Fluoride ion.

Practice by naming these:

•Cl1- •N3- •Br1- •O2-

Write symbols for these:

•Sulfide ion•Iodide ion•Phosphide ion

Polyatomic ions • Groups of atoms that stay together and have overall

charge• Usually end in –ate or -ite

• Acetate: C2H3O21-

• Nitrate: NO31-

• Nitrite: NO21-

• Permanganate: MnO41-

• Hydroxide: OH1- and Cyanide: CN1-?

• Sulfate: SO42-

• Sulfite: SO32-

• Carbonate: CO32-

• Chromate: CrO42-

• Dichromate: Cr2O72-

• Phosphate: PO43-

• Phosphite: PO33-

• Ammonium: NH41+

Know Table 9.3 on page 257

If polyatomic ion begins with H, then combine the word hydrogen with the other polyatomic ion present:

H+ + CO32- → HCO3

-

hydrogen + carbonate → hydrogen carbonate ion

(One of the few positive polyatomic ions)

Section 9.2 – Marble madness

• Pair up with someone• everyone gets a cup• The person in each pair whose birthday is closest to today gets to add 4 marbles in their cups

• The other person keeps an empty cup• Listen for further instructions

SECTION 9.2 P. 260

NAMING & WRITING FORMULAS FOR IONIC

COMPOUNDS

Example: Barium nitrate (note the 2 word name)

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

BaBa2+2+ NONO33--2. Do charges balance?

3. Balance charges , if necessary, using subscripts. Use () if more than one polyatomic ion. Use criss-cross method to balance subscripts.

Not balanced!

( )( ) 22Now balanced.

= Ba(NO3)2

Writing Ionic Compound Formulas

Example: Ammonium sulfate (note the 2 word name)

NHNH44++ SOSO44

2-2-

2. Do charges balance? Not balanced!

( )( )22

Now balanced.

= (NH4)2SO43. Balance charges , if necessary, using subscripts. Use () if more than one polyatomic ion. Use criss-cross method to balance subscripts.

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

Writing Ionic Compound Formulas

Example: Iron (III) chloride (note the 2 word name)

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

FeFe3+3+ClCl--

2. Do charges balance?

3. Balance charges , if necessary, using subscripts. Use () if more than one polyatomic ion. Use criss-cross method to balance subscripts.

Not balanced!

33Now balanced.

= FeCl3

Writing Ionic Compound Formulas

Example: Aluminum sulfide (note the 2 word name)

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

AlAl3+3+ SS2-2-

2. Do charges balance?

3. Balance charges , if necessary, using subscripts. Use () if more than one polyatomic ion. Use criss-cross method to balance subscripts.

Not balanced!

22 33Now balanced.

= Al2S3

Writing Ionic Compound Formulas

Example: Zinc hydroxide (note the 2 word name)

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

ZnZn2+2+ OHOH--

2. Do charges balance?

3. Balance charges , if necessary, using subscripts. Use () if more than one polyatomic ion. Use criss-cross method to balance subscripts.

Not balanced!

( )( )22

Now balanced.

= Zn(OH)2

Naming Ionic CompoundsNaming Ionic Compounds•1. Name cation first, then anion

•2. Monatomic cation = name of element

Ca2+ = calcium ion

•3. Monatomic anion = root + -ide

Cl = chloride

CaCl2 = calcium chloride

Naming Ionic CompoundsNaming Ionic Compounds

•some metals form more than one charge (usually transition metals)

•use Roman numeral in name:

PbCl2 – use anion to find charge on

cation (chloride always 1-)

Pb2+ is lead (II) cation

PbCl2 = lead (II) chloride

(Metals with multiple oxidation states)(Metals with multiple oxidation states)

Things to look for:

1) If cation has ( ), the number in parenthesis is its charge.

2) If anion ends in –ide, likely monoatomic

3) If anion ends in -ate or –ite, it’s polyatomic

Practice by writing formula or name

•Iron (II) Phosphate•Stannous Fluoride•Potassium Sulfide•Ammonium Chromate

•MgSO4

•FeCl3

Section 9.3 p. 268Naming and Writing Formulas for Molecular Compounds

Molecular cmpds…•made of nonmetals•smallest piece… molecule•not bound by opposite charge attraction•can’t use charges to figure # of each atom (no charges present)

Molecular v.s. Ionic Compounds• Ionic: use charges to determine # of each

•Molecular: name tells you # of atoms

•prefix tells exact # of each element

Know these prefixes (Table 9.4 p. 269)

PrefixPrefix MonoMono DiDi TriTri TetraTetra PentaPenta HexaHexa HeptaHepta OctaOcta NonaNona decadeca

ValueValue 11 22 33 44 55 66 77 88 99 1010

Formula Elements # atoms prefixes

N2O

PBr5

P4S3

CS2

IF7

Using Prefixes to name covalent compounds

• To write the name, write two words:

•One exception…..don’t write mono when only one of first element

Prefix name Prefix name -ide

Using Prefixes to name covalent compounds• To write the name, write two words:

•One exception is we don’t write mono if there is only one of the first element.

• Normally, we do not have double vowels when writing names (oa oo)

Prefix name Prefix name -ide

Practice by naming these:

•NO2

•Cl2O7

•CBr4

•CO2

•BaCl2 (This one will not use prefixes, since it is an ionic compound!)

= nitrogen dioxide

= dichlorine heptoxide= carbon tetrabromide

= carbon dioxide

Write formulas for these:•diphosphorus pentoxide•tetraiodine nonoxide•phosphorus trifluoride•carbon tetrahydride•sulfur hexafluoride

more SF6

Section 9.4 p. 271Naming and Writing Formulas for Acids and Bases

Acids are…•Cmpds containing 1 or more H atoms & produces H ions (H1+) when dissolved in H2O•Chem formula starts with H followed by anion•anion determines acid name

Rules for Naming acids: Name it as normal cmpd first

1) If anion ends in –ide:1) Acid name begins w/ prefix hydro- 2) change -ide to -ic acid

• HCl(aq) - hydrogen ion and chloride ion = hydrochloric acid

• H2S(aq) hydrogen ion and sulfide ion = hydrosulfuric acid

Naming Acids• If anion has O, it ends in -ate or -ite2) change suffix -ate to -ic acid (no prefix)

• If you “ate” something acidic, you would probobaly say “ic”!If you “ate” something acidic, you would probobaly say “ic”!

• Example: HNO3 Hydrogen and nitrate ions = Nitric acid

3) change the suffix -ite to -ous acid (no prefix)

• Example: HNO2 Hydrogen and nitrite ions = Nitrous acid

Anion ending Example Acid name Example

-ide Chlor ide, Cl - Hydro-(stem)-ic acid

Hydrochloric acid

-ite Sulf ite, SO3 2- (stem)-ous acid Sulfurous acid

-ate Nitrate, NO3 - (stem)-ic acid Nitric acid

Naming AcidsNaming Acids

Normal ending

____-ide

____-ate

____-ite

Acid name is…

hydro-___-ic acid

_____-ic acid

_____-ous acid

Practice by naming these:

•HF

•H3P

•H2SO4

•HCN

•H2CrO4

Write formulas for these:

•hydroiodic acid•acetic acid•carbonic acid•phosphorous acid•hydrobromic acid

Names and Formulas for Bases•A base is ionic cmpd producing hydroxide ions (OH1-) when dissolved in water

•Bases named same way as other ionic cmpds:•Name of cation (which is a metal) followed by name of anion (hydroxide)

Names and Formulas for Bases• NaOH - sodium hydroxide

• Ca(OH)2 - calcium hydroxide

• To write the formula:

1) Write symbol for metal cation

2) followed by formula for hydroxide ion (OH1-)

3) use criss-cross method to balance charges

Practice by writing the formula for the following:

•Magnesium hydroxide•Iron (III) hydroxide•Zinc hydroxide

Practice by naming the following bases:

•NaOH

•NH4OH

•Ca(OH)2

•Al(OH)3

Section 9.5 p. 274The Laws Governing Formulas and Names

• Review: Law of Conservation of Mass?Review: Law of Conservation of Mass?• Mass neither created or destroyed but is conserved during any chem rxn

Mass reactants = mass products

Mass cmpd = mass of SUM of elements in cmpd

•1. Law of Definite Proportions (mass) - in a sample of a pure cmpd, masses of elements always in same proportions

•CO2 (carbon dioxide)

•CO (carbon monoxide)

Law of Definite ProportionsLaw of Definite Proportions

Law of Multiple Proportions Law of Multiple Proportions (Dalton’s Law)(Dalton’s Law)

•2. Law of Multiple Proportions- Dalton stated whenever 2 elements form more than one cmpd, the different masses of 1 element that combine with the same mass of the other element are in the ratio of small whole numbers

Same mass of oxygen

- Page 275

Law of definite and multiple proportions

Guided Practice Problem 34 p. 275 (p. 90 #34 in workbook)

p. 275 practice problem #34Lead forms two compounds with oxygen. One compound contains 2.98 g of Pb and 0.461 g of O. The other contains 9.89 g of Pb and 0.763 g of O. For a given mass of oxygen, what is the lowest whole number mass ratio of lead in the two compounds?

Step 1. Write the ratio of lead to oxygen for each cmpd.

______g Pb 9.89 g Pb

0.461 g O ______g O

Step 2. Divide the numerator by the denominator in each ratio.

6.46 ______ _______g Pb

_________ g O

Step 3. Write a ratio comparing the first compound to the second.

_____ g Pb/g O

13.0 g Pb/g O

Step 4. Simplify. Note that this ratio has no units (they cancel out)

0.497 = roughly 1

1 __

The mass ratio of lead per gram of oxygen in the two compounds is:

Summary of Naming and Formula Writing

•Naming formulas – flowchart - Figure 9.20, page 277

•Writing formulas – flowchart - Figure 9.22, page 278

Helpful to remember...1. In an ionic compound, the net ionic charge is zero (criss-cross method)

2. An -ide ending generally indicates a binary compound

3. An -ite or -ate ending means there is a polyatomic ion that has oxygen

4. Prefixes generally mean molecular; they show the number of each atom

Helpful to remember...5. A Roman numeral after the name of a cation is the ionic charge of the cation