Nomenclature
A term that describes the system of principles, procedures, rules, or terms related to naming.
We use nomenclature to have a uniform set of rules for naming and writing formulas for chemical compounds.
The IUPAC (International Union of Pure and Applied Chemistry) establishes these rules.
Review of Key Vocabulary
Ionic Compounds – contain bonds between metals and nonmetals A bond involving a TRANSFER of electrons A bond between cations and anions
Cation – An atom that has lost one or more electrons. It has a positive (+) charge.
Anion – An atom that has gained one or more electrons. It has a negative (-) charge.
More Key Vocabulary
Binary Compound – A substance that has only 2 different elements. MgCl2 NaCl H2O
Ternary Compound – A substance that has 3 or more different elements. NaOH H2SO4 CH3Cl
More Key Vocabulary
Prefix – A few letters placed at the beginning of a word to change its meaning.NonmetalCarbon dioxide – CO2
Carbon monoxide – CO
More Key Vocabulary
Ending / Suffix – A few letters placed at the end of a word to change its meaning.LaughablePortableCalcium Sulfate – CaSO4
Calcium Sulfite – CaSO3
Calcium Sulfide – CaSCalcium Oxide - CaO
Ionic Nomenclature
Always write the cation and then the anion.NaCl – NEVER ClNaSodium Chloride – NEVER Chloride Sodium
Binary Ionic Nomenclature (Formula Name)
1-State the name of the cation 2-State the name of the anion
For single elements, drop the ending, substitute the suffix –ide
Cl = Chlorine Chloride F = Fluorine Fluoride Br = Bromine Bromide I = Iodine Iodide O = Oxygen Oxide S = Sulfur Sulfide N = Nitrogen Nitride P = Phosphorus Phosphide C = Carbon Carbide
Practice Binary Ionic Naming
CaCl2 – Calcium chloride
MgO – Magnesium oxideAlF3 – Aluminum fluoride
SrBr2 – Strontium bromide
Ba3N2 – Barium nitride
More Key Vocabulary
Subscript – A number that is written smaller and to the lower right of an element or group of elements telling you how many of that element or group there are.H2O Mg(ClO3)2
More Key Vocabulary
Superscript – A number that is written smaller and to the upper right of an element or group of elements telling you the charge of the element or group of elements.H3O+ Ca+2 SO4
-2 N+3
Binary Ionic Nomenclature (Name Formula)
A little more difficult1 - Write the symbol of cation and anion
including charge2 - Use subscripts to balance the charge
of the compound do not need to write a 1 – it is assumedAll ionic compounds have a neutral charge
Binary Ionic Nomenclature (Name Formula)
Calcium Bromide Ca+2 Br-
There is a +2 charge and a -1 chargeAn extra -1 charge is needed Ca+2 Br- Br-
+2 -1 -1 = 0Need 1 calcium and 2 bromine
CaBr2
“Crisscross” Method
Charge of the cation becomes the subscript for anion
Charge of the anion becomes the subscript for the cation
Aluminum Sulfide Al+3 S-2 Al2S3
Notice the + or – charge is dropped
Simplify to smallest whole numbers Mg+2 O-2 Mg2O2 MgO
Check Work
Practice Binary Ionic Formula Writing
Calcium Sulfide – CaSBarium Chloride – BaCl2Lithium Fluoride – LiFAluminum Nitride – AlNSodium Phosphide – Na3P
More Key Vocabulary
Transition Element – An element in group 3 through 12 on the periodic table.
Oxidation State – A possible charge for an ion of a given element. Located in top right corner of element square on PT All “free elements” have oxidation states of ZERO Many elements only have one oxidation state Many (BUT NOT ALL) transition elements have
more than one oxidation state Can have different charges!
Some, but only a few, other metals have multiple oxidation states
More Key Vocabulary
Roman Numerals – A numeral system established in ancient Rome. The system is based on certain letters which combine to signify a number.
1 = I 2 = II 3 = III 4 = IV 5 = V 6 = VI 7 = VII
Binary Ionic Nomenclature Multiple Oxidation States (Formula Name)
Name the CationIn Parenthesis, write the oxidation
number of the cation using Roman Numerals
Name the Anion
Examples: Iron (II) oxide, Iron (III) oxide
Determining Oxidation NumberBased on Formula
We will use the “Multiply Down, Add Across” Method First, rewrite the formula Second, below each element, write the number of
each element Third, write any known charges, or write an “x” for
an unknown charge We typically know the charges for nonmetals
Group 15 = -3 Group 16 = -2 Group 17 = -1
Fourth, multiply down, and then create an algebraic expression so you may add across.
Multiply Down, Add Across
Fe2O3 FeO
2# of each elementKnown
Charges
3
X -2
2X + -6 = 0
Charge of the Compound(Always 0, unless it is an ion)
Solve 2X = +6
X = +3
The oxidation state of Fe is +3
Iron (III) oxide
1 1
X -2
X + -2 = 0
X = +2
The oxidation state of Fe is +2
Iron (II) oxide
Practice Binary Ionic Naming Using Elements w/. Multiple Oxidation States
MnBr4 – Manganese (IV) bromide
CoCl3 – Cobalt (III) chloride
Cr2O3 – Chromium (III) oxide
Ni3N2 – Nickel (II) nitride
TiS2 – Titanium (IV) Sulfide
Check to make sure the oxidation state you think is correct is a possible oxidation state according to your periodic table
Practice Binary Ionic Formula Writing Using Elements w/. Multiple Oxidation States
Easier than namingUse the “crisscross” method
Remember to reduce subscripts…
Manganese (VII) sulfide – Mn2S7
Chromium (VI) phosphide – CrP2
Copper (II) chloride – CuCl2Platinum (IV) Oxide – PtO2
Final Key Vocabulary
Polyatomic Ion – A particle that contains more than one atom and has a positive or negative charge.
Table E
First 3 are cations, the rest are all anions
Ternary Ionic Nomenclature(Formula Name)
Same RulesWrite Cation first, then Anion
Polyatomic Ions have their own endings
NaClO2 = Sodium chlorite
Practice Ternary Ionic Naming
AgNO3 – Silver nitrateCaSO4 – Calcium sulfateNa2S2O3 – Sodium thiosulfateZn3(PO4)2 – Zinc phosphateKMnO4 – Potassium permanganateHg2O – Dimercury (I) oxideNH4Cl – Ammonium chlorideNH4OH – Ammonium hydroxide
Ternary Ionic Nomenclature(Name Formula)
Trickiest of them all… 1 - Write the symbol of cation and anion
including charge This may mean a whole polyatomic ion
2 - Use subscripts to balance the charge of the compound do not need to write a 1 – it is assumed
3 - Any subscripts for a polyatomic ion need to be written outside parenthesis that surround the polyatomic ion.
May still use “crisscross” method
Ternary Ionic Nomenclature (Name Formula)
Aluminum SulfateAl+3 SO4
-2
There is a +3 charge and a -2 chargeWe need 2 +3 charges and 3 +2 chargesAl+3 Al+3 SO4
-2 SO4-2 SO4
-2 +3 +3 -2 -2 -2 = 0Need 2 aluminums and 3 sulfates
Al2(SO4)2
“Crisscross” Method w/. Polyatomic Ions
Charge of the cation becomes the subscript for anion
Charge of the anion becomes the subscript for the cation
Iron (II) hydroxide Fe+2 OH-
YOU NEED PARENTHESIS There are not 2 H’s, there are 2 OH’s
Simplify to smallest whole numbers Ca+2 S2O3
-2 Ca2(S2O3)2
Check WorkFe(OH)2
CaS2O3
Practice Ternary Ionic Formula Writing
Calcium Sulfite – CaSO3
Ammonium sulfide – (NH4)2S
Cobalt (III) phosphate – CoPO4
Copper (II) nitrate – Cu(NO3)2
Ammonium dichromate – (NH4)2Cr2O7
Ionic Nomenclature Mega Practice
Ca3(PO4)2
Calcium phosphate NaOH
Sodium hydroxide FeCl3
Iron (III) chloride CuSO3
Copper (II) sulfite KCN
Potassium cyanide KBr
Potassium bromide
Sodium sulfide Na2S
Barium nitride Ba3N2
Copper (II) peroxide CuO2
Manganese (VII) oxide Mn2O7
Strontium perchlorate Sr(ClO4)2
Chromium (III) nitrite Cr(NO2)3
More Key Vocabulary
Covalent Compounds – contain bonds between one or two nonmetallic elements
Remember when Ionic Bonding was so short and easy, and Covalent Bonding was so long and tough?OPPOSITE HERENaming Covalent Compounds is EASY
Covalent Prefixes
Only hard part: You need to MEMORIZE these prefixes
# atoms Prefix # atoms Prefix
1 -mono 6 -hexa
2 -di 7 -hepta
3 -tri 8 -octa
4 -tetra 9 -nona
5 -penta 10 -deca
Covalent Nomenclature(Formula Name)
Name the elements in the order they are listed
Use the prefixes to show how many of each elementDON’T use “mono” for the first elementAvoid difficulty saying words by eliminating
“ao” or “oo” by just using “o”Hexaoxide is too difficult to say, just write Hexoxide
Change the ending of the second element to -ide
Covalent Nomenclature Practice (Formula Name)
N2O – Dinitrogen monoxide NO2 – Nitrogen dioxide CO – Carbon monoxide CO2 – Carbon dioxide CCl4 – Carbon tetrachloride NI3 – Nitrogen triiodide ***NH3 – Ammonia ***H2O – Water CS2 – Carbon disulfide N2O5 – Dinitrogen pentoxide
*** There are common names for these we use instead, H2O you should know, NH3 is in your reference table…
Covalent Nomenclature (Name Formula)
Even Easier!Use the prefixes to guide you for what
the subscripts need to be
Dihydrogen monosulfideDi = 2 H2
Mono = 1 SH2S
Covalent Nomenclature Practice (Name Formula)
Carbon tetrabromide – CBr4
Iodine dioxide – IO2
Phosphorus pentachloride – PCl5Dichlorine heptoxide – Cl2O7
Diphosphorus trioxide – P2O3
Ionic + Covalent Nomenclature
The trick to naming and formula writing is determine first if the example is an ionic or covalent compound.
P4O10 Dinitrogen monoxide
TiCl3 Ammonium thiosulfate
Calcium Phosphate Ammonia
Ionic
Ionic
Ionic
Covalent
Covalent
Covalent
Tetraphosphorus decoxide
Titanium (III) chloride
Ca3(PO4)2
N2O
(NH4)2S2O3
NH3
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