Upload
others
View
1
Download
0
Embed Size (px)
Citation preview
Chapter 2Chapter 2Chapter 2Chapter 2
Nomenclature
Chemical Nomenclature
Different types of compounds use different naming rules
– Covalent
– Ionic
– Polyatomic ions
– Acids
• Binary acids
• Oxo Acids
– Other molecules / with other naming rule which we will not
cover:
• Organic Molecules
• Complex Ions
Recognizing Bonding Patterns
�SO2
�NaBr
�H3PO4 (aq)
�P2O5
�BaSO4
�CoF3
�HI (aq)
�HCl (aq)
�CO2
�H2SO4 (aq)
�NiCl2�H2O
�KNO3
�CH3CH2CH3
Before you can name anything, you have to know what it is!!
Recognizing Bonding PatternsBefore you can name anything, you have to
know what it is!!
NiCl2 NaBr
CoF3
KNO3
BaSO4
CO2
H2O
SO2
P2O5
HCl (aq)
HI (aq)
CH2OH
CH3CH2CH3
H2SO4 (aq)
H3PO4 (aq)
Ionic Covalent
Organic
Binary acids
Oxo-acids
Polyatomic Ions
SO42-
PO43-
NO-
Practice on Ionic Charges
• What are the common charges of ions the following elements:
• potassium
• sulfur
• chlorine
• magnesium
• nitrogen
• cobalt
• silver
• zinc
• cadmium55
Many of these can be determined by their location on the periodic table. Others
cannot!
Writing Ionic Formulas
Any binary ionic formula has two parts. A cationand an anion. A metal and a non-metal can
usually form only one compound.
Na+ F-
To find the formula for…
NaF
Mg2+ Cl-
MgCl2
Notice that in both
cases, the charges cancel
Writing Ionic Formulas – “Short Cut”
Na+ F-
Na F
Mg2+ Cl-
Mg Cl2
Think of the “short-cut” method is a bit like cross-multiplication.
Use the charge of
the metal to give you the subscript of the non-metal
Writing Ionic Formulas – “Short Cut”
Fe2+ O2-
Fe2O2
If you use the “short-cut” method, you must reduce the subscripts to the lowest whole number ratio
FeOReduce
This “reduce” rule is for ionic compounds. You do not want to “reduce” for covalent
compounds.
Metal vs Nonmetal Ions
Metal ions are named the same as neutral metal atoms.
Na: sodium atom
Na+: sodium ion
Nonmetal atoms and nonmetal ions differ in the suffix. -ide is added.
F: fluorine atom
F-: fluoride ion
Metals tend to lose
electrons to become stable ions
Non-metals tend to gain electrons to
become stable ions
Common Charges for Main Group Ions
Most of these charges can be deduced by looking at the group number
Common Charges of the d-block
These are the most commoncharges. Other charges are possible
Can also be
Cu+
Can also be
Cr6+
Can
also be Co3+
Ionic Compounds
NaF Sodium Fluoride
MgCl2 Magnesium Chloride
FeO Iron (II) Oxide
Fe2(SO4)3 Iron (III) Sulfate
Name of metal + name of non-metal ion
Metals with more than one possible
charge must be specified explicitly
Polyatomic ions are treated like
any other monoatomic ion
Fe3+
Fe2+
Polyatomic Ions
Some common polyatomic ions
Polyatomic ions are just…well…basically like they sound. Ions
that have many atoms. In reality polyatomic ions are actually
covalent molecules with an overall charge.
(draw the Lewis structure for nitrate)
OH- hydroxideCH3COO- acetateNH4
+ ammoniumCN- cyanide
CO32- carbonate
NO3- nitrate
PO43- phosphate
SO42- sulfate
ClO3- chlorate
oxoanions
Oxoanion Nomenclature
1 More oxygen per_____ate
Most common _____ate
1 Less oxygen _____ite
Still fewer hypo_____ite
• What is the name of NaClO?
• What is the formula for sodium chlorate?
• What is the name of FePO4?1414
Writing Ionic Formulas – Polyatomic Ions
Treat polyatomic ions the same as monoatomic ions when forming compounds. Polyatomic ions stay together as a
unit.
Use “()” for multiplepolyatomic ions only
Fe2+ PO43-
Fe3(PO4)2
Na+ NO3- Na(NO3)
Common Confusion
Nitrate
NO3-
Nitride
N3-
Nitrite
NO2-
Sulfate
SO42-
Sulfite
SO32-
Sulfide
S2-
Phosphate
PO43-
Phosphite
PO33-
Phosphide
P3-
MonoatomicPolyatomic
Examples of Ionic Formulas
• Write the formulas of compounds made by the following pairs of ions.
• Ba + Cl
• Ba + O
• Fe + Cl (HHMMM…what’s the trick here?)
• Na + O
• Mg + NO3
• Zn + F
• Al + S
1717
Ionic formulas
Ionic compounds
• Systematic names
– Names given using established nomenclature system
• Common names
– Names given before nomenclature system was devised
– Many involved in mining / minerals
• Examples
– Lime, calcium oxide CaO
– Galena, lead (II) sulfide PbS
– Fluorite, calcium fluoride CaF2
Ionic Compounds
• Write formulas for the following names:
– aluminum bromide
– titanium(IV) chloride
– chromium(III) sulfide
• Write names for the following formulas:
– Ba3N2
– K2S
– MnF2
1919
Binary Covalent Compounds: 2 Nonmetals
Why do we need prefixes in covalent
compounds?
Write the most metallic element first
Use prefixes to indicate number of
atoms
Never use mono for first element in name
•Mono: 1 (monosyllabic)
•Di: 2
•Tri: 3 (triathlon)
•Tetra: 4 (tetris)
•Penta: 5 (pentagon)
•Hexa: 6 (hexagon)
•Hepta: 7
•Octa: 8 (octagon)
•Nona: 9
•Deca: 10 (decathlon)
2020
Binary Covalent Compounds
• Write formulas for the following names:
– silicon tetrachloride
– carbon monoxide
– tetraphosphorus hexaoxide
• Write names for the following formulas:
– N2O4
– Cl2O7
– SF6
– H2S
– H2Se
– NO2
Although covalent, it is treated as H+ + S2-
Are the following names/formulas correct?
• Iron trichloride
• Magnesium monoxide
• Nitrogen oxide
• NaO
• Iron chloride
• Ferric (III) chloride
• Tin trichloride
• Iron chloride
• Sodium monoxide
• Iron (3) chloride
• Magnesium (II) oxide
• Carbon Sulfate
Acids and Bases
• Hydrogen cation (H+), also called the proton
• Hydroxide anion (OH-)
• Acid: substance that produces H+ in water
– HCl, HNO3, H2SO4, H3PO4
– HCl dissolves in water � H+ (aq) + Cl- (aq)
• Base: substance that produces OH- in water
– NaOH, KOH, Ba(OH)2– NaOH dissolves in water � Na+ (aq) + OH- (aq)
Binary Acids (H+ + anion)
Binary acids: acids with an H+ and an anion.
• Name the following acids:
• HBr (aq)
• HCl (aq)
• HI (aq)
• HF (aq)
• HCN (aq)
2424
hydro_____ic acid
Name of anion
Binary Acids Oxoacids
2626
per_____ate per_____ic acid
_____ate _____ic acid
_____ite _____ous acid
hypo_____ ite hypo_____ous acid
Oxoanion Acid
The name and suffix of the oxoanion determines the name of the acid
SO32-
sulfite
H2SO3
sulfurousacid
Oxoacid Nomenclature Nomenclature
•diphosphorustetraoxide
•XeF4
•carbon tetrachloride
•aluminum oxide
•SnO2
•PbF2
•copper (II) nitrate
•chromium (VI) oxide
•H2SO3 (aq)
•calcium carbonate
•H2CO3 (aq)
•iron (III) oxide
•SiO2
•TiCl3•sulfurous acid
•P4O10
•carbonic acid
•Cr2O3
•lead (II) chromate
•HBr (aq)
•hydrofluoric acid2828
Nomenclature Answers
•P2O4
•xenon tetrafluoride
•CCl4•Al2O3
•tin (IV) oxide
•lead (II) fluoride
•Cu(NO3)2•CrO3
•sulfurous acid
•CaCO3
•carbonic acid
•Fe2O3
•silicon dioxide
•titanium (III) chloride
•H2SO3 (aq)
•tetraphosphorusdecoxide
•H2CO3 (aq)
•chromium (III) oxide
•PbCrO4
•hydrobromic acid
•HF (aq)