Chemical Names Chemical Names and Formulasand FormulasUnit 5Unit 5

Counting AtomsCounting Atoms The subscript tells how many of that The subscript tells how many of that

element is present. element is present. Eg: HEg: H22OO22= 2 hydrogen, 2 oxygen= 2 hydrogen, 2 oxygen If there is no subscript next to the If there is no subscript next to the

symbol, it counts as “1”.symbol, it counts as “1”. Eg: NaCl = 1 sodium & 1 chlorineEg: NaCl = 1 sodium & 1 chlorine

Counting AtomsCounting Atoms If the subscripted number is outside If the subscripted number is outside

of the parenthesis, it is distributed to of the parenthesis, it is distributed to all elements within the parenthesis.all elements within the parenthesis.

Eg: Ca(NOEg: Ca(NO33))22 = NO = NO33 x 2. x 2. A preceeding coefficient is multiplied A preceeding coefficient is multiplied

to all atoms in the compound.to all atoms in the compound. Eg: 2NaCl = 2 sodium & 2 chlorineEg: 2NaCl = 2 sodium & 2 chlorine

Counting AtomsCounting Atoms

Calcium Carbonate: Calcium Carbonate: CaCaCCOO33..

CaCa = = CalciumCalcium = = 11

CC = = CarbonCarbon = = 11

OO = = OxygenOxygen = = 33

Total atomsTotal atoms = = 55

Counting AtomsCounting Atoms

Magnesium Hydroxide: Magnesium Hydroxide: MgMg(O(OHH))22..

MgMg = = MagnesiumMagnesium = = 11

H =H =

OO = = Oxygen Oxygen = = 22

Total atomsTotal atoms = = 55

HydrogenHydrogen = = 22

Counting AtomsCounting Atoms

Acetic Acid: 2Acetic Acid: 2HHCC22HH33OO22..

HH = = Hydrogen Hydrogen = = 2 + 6 = 82 + 6 = 8

C =C =

OO = = Oxygen Oxygen = = 44

Total atomsTotal atoms = = 1616

Carbon Carbon = = 44

Now complete the Counting Atoms review Now complete the Counting Atoms review worksheet.worksheet.

Chemical FormulasChemical Formulas The simplest compounds contain 2 The simplest compounds contain 2

elements and are called elements and are called BinaryBinary.. In ionic binary compounds, a In ionic binary compounds, a cationcation

and an and an anionanion join together to form a join together to form a neutral compound.neutral compound.

Ionic compounds are made from a Ionic compounds are made from a metal and a non-metal.metal and a non-metal.

IMPORTANT: ALL COMPOUNDS ARE IMPORTANT: ALL COMPOUNDS ARE NEUTRALNEUTRAL!!!!!!

Cation + Anion = Ionic Compound

Chemical FormulasChemical Formulas Potassium Bromide = KBrPotassium Bromide = KBr Calcium Bromide = CaBrCalcium Bromide = CaBr22

Lithium Fluoride = LiFLithium Fluoride = LiF Lithium Oxide = LiLithium Oxide = Li22OO Note that the subscript has nothing Note that the subscript has nothing

to do with the name of the ionic to do with the name of the ionic compound.compound.

Chemical NamesChemical Names Example: LiFExample: LiF The element with the positive charge, The element with the positive charge,

cation (the metal) is written first. cation (the metal) is written first. This element is given its usual name, in This element is given its usual name, in

this case, Lithium. this case, Lithium. The second element is the anion. It’s The second element is the anion. It’s

name will be changed to end in name will be changed to end in “-ide”“-ide”. . Fluorine is changed to Fluoride.Fluorine is changed to Fluoride.

The compound’s name = Lithium The compound’s name = Lithium Fluoride.Fluoride.

Chemical Formula forChemical Formula forPotassium BromidePotassium Bromide

Write the two symbols for the ions in Write the two symbols for the ions in the compounds, placing the symbol the compounds, placing the symbol for the cation first.for the cation first.

K Br Determine the charge of each ion from the oxidation Determine the charge of each ion from the oxidation

state on the periodic table.state on the periodic table.

+1 -1

If the charges are equal, drop them If the charges are equal, drop them and write the formula.and write the formula.

KBr

Balanced!

Calcium BromideCalcium Bromide If the charges are not equal, “lasso” If the charges are not equal, “lasso”

the number the number onlyonly (not the sign) to (not the sign) to write the formula.write the formula.

Ca Br+ 2 - 1 CaBr2

After seeing more examples, complete After seeing more examples, complete practice problems 1-10 on your practice problems 1-10 on your worksheet.worksheet.

NOT Balanced!

2 1

Transition Elements and Transition Elements and Roman NumeralsRoman Numerals

Some metals can form more than Some metals can form more than one type of ion and therefore, have one type of ion and therefore, have more than one possible charge.more than one possible charge.

To tell which charge is used, the To tell which charge is used, the chemical namechemical name contains a Roman contains a Roman numeral.numeral.

The The Roman numeralRoman numeral tells the tells the charge of the cation.charge of the cation.

Transition Elements and Transition Elements and Roman NumeralsRoman Numerals

Roman Roman numeralsnumerals are are NEVER NEVER used in the used in the chemical formula!!chemical formula!!

Rules to Write a Chemical Rules to Write a Chemical Formula when Roman Formula when Roman Numerals are PresentNumerals are Present

To write the chemical formula for To write the chemical formula for Iron (III) Sulfide:Iron (III) Sulfide:

Write the two symbols for the ions in Write the two symbols for the ions in the compounds, placing the symbol the compounds, placing the symbol for the cation first.for the cation first.

Get the charge of the metal from the Get the charge of the metal from the Roman numeral in ( ) after the metal Roman numeral in ( ) after the metal and look up the anion’s charge.and look up the anion’s charge.

Fe S+ 3 - 2 Fe2S3 2 3

Rules to Write a Chemical Rules to Write a Chemical Name when Roman Name when Roman

Numerals are NeededNumerals are Needed If the metal has more than one If the metal has more than one

oxidation state, the chemical name oxidation state, the chemical name will contain a Roman numeral.will contain a Roman numeral.

MnO3

Start with the anion to determine its Start with the anion to determine its overall negative charge.overall negative charge.Mn can have a charge of +7, 6, 4, 2 or 3

Oxygen has a charge of -2 and there are 3 for a total charge of -6.

Mn must have a charge of +6 to neutralize the -6 charge.

Now write the chemical name using a Now write the chemical name using a roman numeral to represent the roman numeral to represent the charge of the Manganese.charge of the Manganese.

Manganese (VI) Oxide You CANNOT lasso up to determine You CANNOT lasso up to determine

the Roman numeral.the Roman numeral.

Let’s Try AgainLet’s Try Again Write the chemical name of FeWrite the chemical name of Fe22OO33..

Fe2O3

Fe can have a charge of +2 or 3

Oxygen has a charge of -2 and there are 3 for a total charge of -6.

The 2 Fe ions must have an overall charge of +6. So 6/2 = +3.

Now write the chemical name.Now write the chemical name. Iron (III) Oxide

Now do part C of your worksheet.Now do part C of your worksheet.

Rust

Polyatomic Ions in NamesPolyatomic Ions in Names The cation keeps its name.The cation keeps its name.

CaCO3

Calcium CarbonateMade of more than one element so it is a polyatomic

ion. The polyatomic ion also keeps its name, even though The polyatomic ion also keeps its name, even though

it is an anion.it is an anion.

Polyatomic Ions in FormulasPolyatomic Ions in FormulasBarium PhosphateBarium Phosphate

We recognize PhosphWe recognize Phosphateate as a as a polyatomic ion because it ends in polyatomic ion because it ends in “ate”“ate”..

Get the charge of the polyatomic ion Get the charge of the polyatomic ion from the chart.from the chart.

Use the periodic table for the charge Use the periodic table for the charge on your element.on your element.

Barium PhosphateBarium Phosphate Write the chemical symbols.Write the chemical symbols.

Ba PO4

Add each ion’s charge.Add each ion’s charge.

+ 2 - 3

Are the charges balanced?Are the charges balanced? Let’s Lasso!Let’s Lasso! NO!!NO!!

2 3

We have 2 “POWe have 2 “PO44” ions so we need ” ions so we need parentheses to separate the ion from parentheses to separate the ion from the extra subscript.the extra subscript.

Ba3(PO4)2

Let’s Try AgainLet’s Try Again Write the formula for Magnesium Write the formula for Magnesium

Hydroxide.Hydroxide.

Mg OH+ 2 - 1 2 1

We have 2 “OH” ions so we need We have 2 “OH” ions so we need parentheses to separate the ion from parentheses to separate the ion from the subscript.the subscript.

Mg(OH)2

Now do part D of your worksheet.Now do part D of your worksheet.

Covalent CompoundsCovalent Compounds Covalent compounds are made from Covalent compounds are made from

2 non-metals and are binary.2 non-metals and are binary. Since there are no ions involved, we Since there are no ions involved, we

don’t look at charges.don’t look at charges. The subscript to the right of the The subscript to the right of the

element tells the prefix to use for element tells the prefix to use for that element.that element.

SOSO22 = Sulfur = Sulfur DiDioxideoxide

Covalent Compound Covalent Compound PrefixesPrefixes

Mono = oneMono = one Di = twoDi = two Tri = threeTri = three Tetra = fourTetra = four Penta = fivePenta = five

Hexa = sixHexa = six Hepta = sevenHepta = seven Octa = eightOcta = eight Nona = nineNona = nine Deca = tenDeca = ten

Hexagon

Triangle

Some Covalent Some Covalent CompoundsCompounds

NF3 nitrogen trifluoride

N2Cl4 dinitrogen tetrachloride

NO2 nitrogen dioxide

N2O dinitrogen monoxideTOXIC!

Laughing Gas Now do part E of your Now do part E of your worksheet.worksheet.

Naming AcidsNaming Acids Acids = compounds that give off Acids = compounds that give off

hydrogen ions when dissolved in hydrogen ions when dissolved in water.water.

Acids begin with H.Acids begin with H. Acids will always have some H next to Acids will always have some H next to

an anion.an anion. The The anionanion determines the name. determines the name.

Binary AcidsBinary Acids Binary AcidsBinary Acids contain only 2 elements, contain only 2 elements,

the cation being hydrogen. Add the the cation being hydrogen. Add the prefix prefix hydro-hydro-,, take the anion name take the anion name and change the suffix and change the suffix -ide-ide to to –ic–ic. .

HCl(aq)HCl(aq) HydroHydrochlorchloricic Acid Acid

HF(aq)HF(aq) HydroHydrofluorfluoricic Acid Acid

HI(aq)HI(aq) HydroHydroiodiodicic Acid Acid

Binary AcidsBinary Acids

Exceptions:Exceptions:HCN = Hydrocyanic Acid HCN = Hydrocyanic Acid

CN = Cyanide CN = CyanideHNHN33 = Hydroazoic Acid = Hydroazoic Acid

azo = Nitrogen azo = Nitrogen

OxyacidsOxyacids Ternary AcidsTernary Acids contain 3 elements, contain 3 elements,

hydrogen, hydrogen, oxygenoxygen and one other and one other element (a polyatomic ion).element (a polyatomic ion).

The suffix is determined by the The suffix is determined by the number of oxygens. number of oxygens.

If the anion ends in If the anion ends in -ate-ate, change the , change the suffix to suffix to –ic acid–ic acid..

HNOHNO33 = = Hydrogen & NitrHydrogen & Nitrateate = =

NitrNitricic AcidAcid

More OxyacidsMore Oxyacids

HH22SOSO44 = = Hydrogen & SulfHydrogen & Sulfateate = =

SulfurSulfuricic AcidAcid

HClOHClO33 = = Hydrogen & ChlorHydrogen & Chlorateate = =

ChlorChloricic AcidAcid

If the anion has one less oxygen & ends If the anion has one less oxygen & ends in in -ite-ite, change the suffix to , change the suffix to –ous acid–ous acid..

More OxyacidsMore Oxyacids

HNOHNO22 = = Hydrogen & NitrHydrogen & Nitriteite = =

NitrNitrousous AcidAcidHH22SOSO33 = = Hydrogen & SulfHydrogen & Sulfiteite = =

SulfurSulfurousous AcidAcid

HClOHClO22 = = Hydrogen & ChlorHydrogen & Chloriteite = =

ChlorChlorousous AcidAcid

Name these AcidsName these Acids

HFHF HH33PP

HH33POPO44

HH33POPO33 HCNHCN HH22CrOCrO44

Hydrofluoric AcidHydrofluoric Acid Hydrophosphic AcidHydrophosphic Acid Phosphoric AcidPhosphoric Acid Phosphorous AcidPhosphorous Acid Hydrocyanic AcidHydrocyanic Acid Chromic AcidChromic Acid

OxyacidsOxyacids If a third acid is formed with fewer If a third acid is formed with fewer

oxygens than oxygens than -ite-ite, it is given the , it is given the prefix prefix hypo-hypo- and the suffix and the suffix –ous–ous. .

E.g. HClO = Hydrogen & E.g. HClO = Hydrogen & hypochlorite = hypochlorite = HypoHypochlorchlorousous AcidAcid

If it has one more oxygen than If it has one more oxygen than -ate-ate, , it is given the prefix it is given the prefix per-per- and the and the suffix suffix –ic–ic. .

E.g. HClOE.g. HClO44 = hydrogen & perchlorate = hydrogen & perchlorate = = PerPerchlorchloric Acidic Acid. .

Writing Formulas for Writing Formulas for AcidsAcids

Hydrogen will always be first.Hydrogen will always be first. The name tells you the anion.The name tells you the anion. Make sure the molecule is neutral.Make sure the molecule is neutral. If the name starts with the prefix If the name starts with the prefix

hydro-hydro- and ends with and ends with -ic-ic, there is no , there is no oxygen in the formula.oxygen in the formula.

If there is no prefix, the suffix If there is no prefix, the suffix –ate–ate comes from comes from –ic–ic and and –ite–ite comes fromcomes from –ous–ous..

Write Formulas for these Write Formulas for these AcidsAcids

hydroiodic acidhydroiodic acid acetic acidacetic acid carbonic acidcarbonic acid phosphorous acidphosphorous acid hydrobromic acidhydrobromic acid

HIHI HCHC22HH33OO22

HH22COCO33

HH33POPO33

HBrHBr

Naming Organic Naming Organic CompoundsCompounds

HydrocarbonsHydrocarbons are compounds made are compounds made of of onlyonly carbon and hydrogen linked carbon and hydrogen linked in long chains.in long chains.

AlkanesAlkanes – have single bonded – have single bonded carbons so they are saturated.carbons so they are saturated.

Naming Organic CompoundsNaming Organic Compounds Alkenes – have double bonded Alkenes – have double bonded

carbons so they are unsaturated.carbons so they are unsaturated. Alkynes – have triple bonded carbonsAlkynes – have triple bonded carbons We’ll work with We’ll work with alkanesalkanes so so

hydrocarbons will have the suffix hydrocarbons will have the suffix ––aneane. .

Organic StemsOrganic Stems1 carbon = 1 carbon = meth-meth- 6 carbons = hex-6 carbons = hex-

2 carbons = eth-2 carbons = eth- 7 carbons = hept-7 carbons = hept-

3 carbons = prop-3 carbons = prop- 8 carbons = oct-8 carbons = oct-

4 carbons = but-4 carbons = but- 9 carbons = non-9 carbons = non-

5 carbons = pent-5 carbons = pent- 10 carbons = dec-10 carbons = dec-

Organic CompoundsOrganic Compounds If the atoms are linked in a ring If the atoms are linked in a ring

rather than in a chain, the prefix rather than in a chain, the prefix cyclo-cyclo- is added. is added.

Hexane in a chainHexane in a chainCHCH33-CH-CH22- CH- CH22- CH- CH22- CH- CH22- CH- CH33. .

Cyclohexane has 6 carbons in a ring. Cyclohexane has 6 carbons in a ring.

Each point represents a carbon.

Organic CompoundsOrganic Compounds If the chain is straight:If the chain is straight:

C CnnHH2n+22n+2 n=#carbons n=#carbons

E.g. CE.g. C33HH(2(2××3)+23)+2 = C = C33HH88 = Propane = Propane

CHCH33-CH-CH22-CH-CH33

If the chain is cyclic:If the chain is cyclic: C CnnHH2n2n

E.g. CE.g. C33HH66 = cyclopropane = cyclopropane