Names & Formulas of Ionic Compounds
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Transcript of Names & Formulas of Ionic Compounds
Names & Formulas of Ionic Compounds
Ionic compounds are named using the names of the ions that compose them.
To name an ionic compound:
Cation name followed by anion name
Learn the names and formulas of the ions in your syllabus.The following slides explain the
systematic way that ions are named.
Naming Cations
Cations formed from metal ions have the same name as the metal.
K+ potassium ionCa2+ calcium ionAl3+ aluminum ion
Naming Cations
Cations with varying charges
the charge of the specific cation is given by Roman numeral in parentheses after the name of the metal
Fe2+ iron (II) ionFe3+ iron (III) ionCu+ copper (I) ionCu2+ copper (II) ion
Naming Cations
One common polyatomic cation found in ionic compounds
NH4+ ammonium ion
Note: Compounds whose formulas start with NH4 are ionic even though they are composed only of non-metals.
Naming Anions
Monoatomic anions
drop the ending of the element’s nameadd “ide”
N nitrogen O oxygen
N3- O2-nitride oxide
Naming Anions
Some simple polyatomic anions use the “ide” ending as well
OH- hydroxideCN- cyanideO2
2- peroxide
Naming Oxyanions
Oxyanions (polyatomic anions containing oxygen) have names ending in:“ate” most common
oxyanionof the element
“ite” same charge, 1 less oxygen
NO3- nitrate SO4
2- sulfateNO2
- nitrite SO32- sulfite
CO32- carbonate PO4
3- phosphatePO3
3- phosphite
Oxyanions (cont.)
Some elements like the halogens can form more than two oxyanions:
“per” 1 more O than the “ate” oxyanion“hypo” 1 less O than the “ite” oxyanion
ClO4- perchlorate
ClO3- chlorate
ClO2- chlorite
ClO- hypochlorite
Oxyanions Anions derived by adding H+ to an oxyanion:
add “hydrogen” or “dihydrogen” as prefix to oxyanion name
CO32- carbonate
HCO3- hydrogen carbonate
(usually called bicarbonate)
PO43- phosphate
H2 PO4- dihydrogen phosphate
Naming Ionic Compounds
Name ionic compounds using cation name followed by anion name
NaCl sodium chlorideCaBr2 calcium bromideNaClO sodium hypochlorite
Cu(NO3)2 copper (II) nitrate
Naming Ionic Compounds
Example: Write the names of these ionic compounds.
Na2OFeCl3
(NH4)3PO4
KClO4
SnO2
Cu(NO3)2
Writing Formulas from Names
Given the name of a compound, you must be able to write its formula.Identify the symbol and charge for each
ion.
Determine the correct number of each ion needed to balance the charges (write an electrically neutral formula).
Writing Formulas from Names
Example: Write the empirical formula for ammonium sulfate
(NH4)2SO4
ammonium
sulfate
NH4+
SO42-
SO42-
NH4+
NH4+
Writing Formulas from Names
Example: Write the formulas for these ionic compounds
lithium chloridebarium nitratesodium perchlorateiron(III) oxidesodium hydrogen phosphateLead (IV) sulfate
Names & Formulas of Acids
Acid: a substance whose molecules form H+ ions when dissolved in waterHCl (aq)HCN (g)HClO3 (aq)
Name of acid depends on:Type of acid
Oxygen present or notPure or aqueous
Name of anion
Names & Formulas of Acids
Three naming systems for acids:
Oxyanion-based acids (with oxygen)
Acids with “ide” anions (no oxygen)aqueous solutionsgases
Oxyanion Based Acids
If the acid contains oxygen, identify the anion and write its name
Change the ending of the anion name:
“ite” “ous acid”“ate” “ic acid”
HClO4 perchlorate perchloric acidHClO2 chlorite chlorous acid
Oxyanion Based Acids
Naming acids derived from oxyanions of S and P:H2SO4 :
oxyanion = sulfateSulfic acid Sulfuric acid
H3PO4 :oxyanion = phosphatePhosphic acid Phosphoric acid
Acids Without Oxyanions
If the acid does not contain oxygen and is dissolved in water (aq):
hydro + (anion name minus “ide”) + “ic acid”
HCl (aq) hydro + chloride + ic acid
hydrochloric acid“Hydro” = no oxygen and (aq)
Acids Without Oxyanions
If the acid does not contain oxygen and is a gas (g):
name the acid as an ionic compound:hydrogen followed by anion name
HCl (g) hydrogen chloride
“Hydrogen” = no oxygen and (g)
Naming Acids
To name an acid:Does it have oxygen?
YesWrite name of anionChange “ate” to “ic acid”Change “ite” to “ous acid”
If no oxygen, is it (aq)?Yes
Start with hydroAdd the name of anionChange “ide” to “ic acid”
Naming Acids
If no oxygen, is it (g)?Yes
Start with hydrogenAdd the name of the anion
Naming Acids
Example: Name the following acids.
HNO3
HBr (aq)
H2S (g)
Writing Formulas from Acid Names To write the formula of an acid starting with the
name of the acid, first decide which category of acid it is:Oxyanion based No oxygen, (aq) (begins with “hydro”)No oxygen, (g) (begins with
“hydrogen”)
Write the formula for the anion (including charge).
Add enough H+ ions to make a neutral compound.
Writing Formulas from Acid Names
Example: Write the formula for perchloric acid.
Category: oxyanion containing acid
Anion: perchloric acid perchlorate (ClO4-)
Formula: HClO4
ClO4-H+
Writing Formulas from Acid Names
Example: Write the formula for each of the following acids.
Phosphoric acid:
Hydrobromic acid:
Hydrogen cyanide:
Naming Acids
You must know the names and formulas for the following acids:
HF (aq) hydrofluoric acidHCl (aq) hydrochloric acidHBr (aq) hydrobromic acidHI (aq) hydroiodic acidHClO4 perchloric acidHClO3 chloric acidH2SO4 sulfuric acidHNO3 nitric acid
Naming Acids
You must know the names and formulas for the following acids:
H3PO4 phosphoric acidHC2H3O2 acetic acidH2CO3 carbonic acidH2S (g) hydrogen sulfideHCN (g) hydrogen cyanide
Binary Molecular Compounds
Binary molecular compound: compound composed of molecules with two different types of atoms
Remember: Many molecular compounds are composed strictly of non-metals.
SO2 N2O4
H2O PCl5
P4O10 CO
Binary Molecular Compounds
The names of binary molecular compounds give both the type and number of each type of atom present.
The general pattern for naming binary molecular compounds is:
prefixprefix element name element name prefixprefix element name with ide ending element name with ide ending
Binary Molecular Compounds
The first element is named using the name of the element.
The second element is named using the “ide” ending.
Greek prefixes are used to indicate the number of each type of element present.
prefixprefix element name element name prefixprefix element name with ide ending element name with ide ending
Greek Prefixes
Prefix Meaningmono 1di 2tri 3tetra 4penta 5hexa 6hepta 7octa 8nona 9deca 10
You must know these!!
P4S10 =
tetraphosphorus decasulfide
Binary Molecular Compounds
Special conventions for using Greek prefixes:Mono is never used with the first
element
The “a” or “o” in the prefix is dropped if the name of the element begins with a vowel.
CO: carbon monooxide carbon monoxide
Binary Molecular Compounds
Example: Name the following compounds.
N2O4
PCl5
Cl2O7
Binary Molecular Compounds
Example: Write the formulas for the following compounds.
tetraphosphorus decoxide
sulfur trioxide
disulfur dichloride
Naming — Revisited
Before you can correctly name a compound or write its formula, YOU MUST determine which type of compound it is:
Ionic starts with a metal or NH4
Acid starts with H or HnBinary Molecular two non-metals
THEN use the appropriate naming system or method to write the formula.
Simple Organic Compounds
Organic compounds: compounds that contain carbon and
hydrogen, often in combination with oxygen or nitrogen.
Simple Organic Compounds
You must know the names and structural formulas of the following simple organic compounds:MethanePropaneMethanolEthanolAcetic acidAcetone
Simple Organic Compounds
Methane:
Ethane:
CH
HH
H
CH
H
H
C
H
H
H
Methanol:
Ethanol:
CH
H
H
C
H
H
OH
C
H
H
H
H
C
H
H
OH
C
H
H
OH
Simple Organic Compounds
Propane:
Acetic Acid:
C
H
H
H
H
C
H
H
C
H
H
OH
C
H
H
H
C
H
H
H
H
C
H
H
C
H
H
C
H
H
H
C
O
OH
Acetone:
C
H
H
H
H
C
C
H
H
C
H
H
H
C
O
OH
O
Common “Household” Chemicals
You are responsible for knowing the names and formulas for the chemical present in:Water (H2O)Ammonia (NH3)Baking soda
sodium bicarbonateNaHCO3
Natural gasMethaneCH4
VinegarAcetic acidHC2H3O2 (structure on previous slide)
Common “Household” Chemicals
You are responsible for knowing the names and formulas for the chemical present in:Table salt
Sodium chlorideNaCl
BleachSodium hypochloriteNaClO
Hydrogen peroxideH2O2
Common “Household” Chemicals
You are responsible for knowing the names and formulas for the chemical present in:Drinking alcohol
EthanolC2H5OH
Rubbing alcoholIsopropyl alcohol
Nail polish removerAcetone
CH
H
H
C
H
H
OH
C
H
H
H
H
C
C
H
H
C
H
H
H
C
O
OH
OH
H C C C HH OH
HHH
H