names & formulas (nomenclature). anatomy of a chemical formula al 2 so 4 numbers at the bottom...
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Names & FormulasNames & Formulas
(Nomenclature)(Nomenclature)
Anatomy of a Chemical Formula Anatomy of a Chemical Formula
AlAl22SOSO44
Numbers at the bottom are called Numbers at the bottom are called subscripts.subscripts.
They tell They tell how many atomshow many atoms of one type are in a of one type are in a compound.compound.
CaCa+2+2
Numbers at the top are called Numbers at the top are called superscriptssuperscripts. .
They tell you the They tell you the chargecharge of the atom. of the atom.
Polyatomic IonsPolyatomic Ions
Group of atoms that have an overall charge. Group of atoms that have an overall charge. You will find both subscripts and superscripts You will find both subscripts and superscripts in polyatomic ions.in polyatomic ions.
COCO33-2-2 carbon = 1
oxygen = 3
overall charge = -2
3 Categories of Compounds3 Categories of Compounds
1.1. IonicIonic
2.2. Acids & BasesAcids & Bases
3.3. MolecularMolecular
1) 1) Ionic CompoundsIonic CompoundsContain IONIC bonds.Contain IONIC bonds.Formed between Formed between metalsmetals and and non-metalsnon-metals..Ions combine in small, Ions combine in small, whole number ratios.whole number ratios.The sum of oxidation The sum of oxidation numbers will be zero! (they numbers will be zero! (they are neutral)are neutral)
Binary Ionic CompoundsBinary Ionic Compounds
All contain All contain twotwo elements.elements.
All end in All end in “ide”“ide”..
Binary Ionic CompoundsBinary Ionic Compounds
To write formula:To write formula:
1)1) Write Write ++ and and - - ions.ions.
2)2) Reduce oxidation numbersReduce oxidation numbers, , if possible.if possible.
3)3) “Criss-Cross”“Criss-Cross” number only number only to become subscript for to become subscript for other ion.other ion.
Examples…Examples…
sodium chloridesodium chloride
magnesium nitridemagnesium nitride
calcium oxidecalcium oxide
NaCl
Mg3N2
CaO
Binary Ionic CompoundsBinary Ionic Compounds
To Name:To Name:
1)1) CationsCations (+) retain the name (+) retain the name of the element.of the element.
2)2) AnionsAnions (-) keep the root (-) keep the root name but add name but add “ide”“ide” ending. ending.
Examples…Examples…
LiFLiFLithium fluorideLithium fluoride
SrClSrCl22Strontium chlorideStrontium chloride
AlAl22OO33
Aluminum oxideAluminum oxide
Multi-Charge MetalsMulti-Charge Metals
Most of the Most of the transition metals transition metals (and lead and tin)(and lead and tin) have have variable oxidation numbersvariable oxidation numbers. .
(they can have more than one)(they can have more than one)
Roman numerals are used Roman numerals are used to indicate charges for these to indicate charges for these elements.elements.Roman numerals always Roman numerals always belong to the metal.belong to the metal.(are always positive)(are always positive)
IMPORTANT EXCEPTIONS!IMPORTANT EXCEPTIONS!
Silver always forms a 1+ ion.Silver always forms a 1+ ion.
Zinc always forms a 2+ ion.Zinc always forms a 2+ ion.
Cadmium always forms a Cadmium always forms a
2+ ion.2+ ion.
Examples…Examples…
Iron (II) oxideIron (II) oxide
iron(III) oxideiron(III) oxide
chromium (IV) sulfidechromium (IV) sulfide
FeO
Fe2O3
CrS2
Examples…Examples…
CuOCuOCopper (II) oxideCopper (II) oxide
CrCr22SeSe33
chromium (III) selenidechromium (III) selenide
PbSPbS22
Lead (IV) sulfideLead (IV) sulfide
Ternary Ionic CompoundsTernary Ionic CompoundsContain 3 or more Contain 3 or more elements. (not binary)elements. (not binary)
Contain at least oneContain at least onePolyatomic Ion.Polyatomic Ion.
(look on the back of your P.T.)(look on the back of your P.T.)
Polyatomic IonsPolyatomic Ions
All P.A.I. contain at least All P.A.I. contain at least two different elements.two different elements.
Example:Example:
Chlorate Chlorate ClO ClO33-1-1
(Contains chlorine and oxygen)(Contains chlorine and oxygen)
To name/write formulas:To name/write formulas:
Use the same rules as Use the same rules as binary ionic compounds.binary ionic compounds.
Enclose P.A.I. in Enclose P.A.I. in parenthesis when parenthesis when necessary.necessary.
Examples…..Examples…..
Aluminum phosphateAluminum phosphate
AlPOAlPO44
Sodium sulfateSodium sulfate
NaNa22SOSO44
Iron (II) bromateIron (II) bromate
Fe(BrOFe(BrO33))22
Examples…Examples…CaCOCaCO33
Calcium carbonateCalcium carbonate
Cu(NOCu(NO33))22
Copper (II) nitrateCopper (II) nitrate
(NH(NH44))33NN
Ammonium nitrideAmmonium nitride
Naming Naming
Acids & BasesAcids & Bases
2)2) Acids and BasesAcids and Bases::
All traditional acids begin All traditional acids begin with Hydrogen (H).with Hydrogen (H).
All traditional bases end All traditional bases end with Hydroxide (OH).with Hydroxide (OH).
Acids are easy to recognize Acids are easy to recognize because they begin with “H”. because they begin with “H”.
Bases are easy to recognize Bases are easy to recognize because they end with “OH”.because they end with “OH”.
BasesBasesThere are no special rules There are no special rules for naming bases! (they are for naming bases! (they are ionic)ionic)
EX: NaOHEX: NaOHSodium hydroxideSodium hydroxide
Binary AcidsBinary Acids
Have only two elements.Have only two elements.
(hydrogen and a non-(hydrogen and a non-metal from the Periodic metal from the Periodic Table)Table)
To Name:To Name:
1)1)Use the prefix “hydro”.Use the prefix “hydro”.
2) Add the suffix “ic”.2) Add the suffix “ic”.Examples:Examples:
HHClCl
HH33NN
hydrohydrochlorchloric acidic acid
hydrohydronitrnitric acidic acid
To write formulas:To write formulas:
1)1) Start with HStart with H+1+1
2)2) End with negative End with negative
(non-metal) ion from (non-metal) ion from
periodic table.periodic table.
3)3) “Criss-Cross”.“Criss-Cross”.
Examples:Examples:
Hydroiodic acid Hydroiodic acid
Hydrophosphoric acidHydrophosphoric acid
HI
H3P
Ternary AcidsTernary Acids
Have at least three Have at least three elements: elements:
(H and a polyatomic ion)(H and a polyatomic ion)
To Name:To Name:
1) 1) Use NO “hydro” prefix!Use NO “hydro” prefix!
2) Add suffix:2) Add suffix:
if “ate” ion, “ic” suffixif “ate” ion, “ic” suffix
if “ite” ion, “ous” suffix if “ite” ion, “ous” suffix
Examples…Examples…
HClOHClO33
HH22SOSO33
chloric acidchloric acid
sulfous acid
To write formula:To write formula:
1)1) Start with HStart with H+1+1
2)2) End with negative End with negative
(polyatomic) ion.(polyatomic) ion.
3)3) “Criss-Cross”.“Criss-Cross”.
Examples:Examples:
perchloric acidperchloric acid
chlorous acidchlorous acid
HClO4
HClO2
3)3) MolecularMolecular::
Used to name Used to name CovalentlyCovalently bonded atoms.bonded atoms.
Made up of Made up of non-metalsnon-metals only.only.
Molecular Molecular CompoundsCompounds
Contain Contain COVALENTCOVALENT bonds. bonds.
The same elements can The same elements can combine in various ways.combine in various ways.
PrefixesPrefixes are used to tell the are used to tell the difference between them.difference between them.
We will only learn We will only learn BINARYBINARY molecular compounds.molecular compounds.
BinaryBinary = only contains two = only contains two different elements.different elements.
All binary compounds end All binary compounds end in in “ide”“ide”..
Prefixes:Prefixes:
1 = mono1 = mono 6 = hexa6 = hexa
2 = di2 = di 7 = hepta7 = hepta
3 = tri3 = tri 8 = octa8 = octa
4 = tetra4 = tetra 9 = nona9 = nona
5 = penta5 = penta 10 = deca10 = deca
To name:To name:
Use prefixes on first atom, Use prefixes on first atom, except for “mono”.except for “mono”.
Always use prefixes on Always use prefixes on the last atom.the last atom.
Change ending to “ide”.Change ending to “ide”.
Examples…Examples…
SS22OO33
COCO
OFOF22
disulfur trioxide
carbon monoxide
oxygen difluoride
To write formulas:To write formulas:
Look at prefixes Look at prefixes attached to each attached to each element to determine element to determine subscript.subscript.
Examples…Examples…
Arsenic pentiodideArsenic pentiodide
Carbon ditellurideCarbon ditelluride
Diphosphorus trioxideDiphosphorus trioxide
AsI5
CTe2
P2O3