Identify
Compounds
As Ionic, Acid, or Molecular
Types of Compounds
Three types of Compounds:
Ionic: start with a metal or ammonium
transfer of e’s, ionic bonding
--Acids: Formula starts with hydrogen
--Molecular: contain only nonmetals
sharing of e’s, covalent bonding
Types of Compounds
Three types of Compounds:
--Ionic: Formula starts with a metal or
ammonium
Examples:
CaCl2
(NH4)2CO3
AgNO3
--Acids: formula starts with hydrogen
Examples: H2S
H2SO4
H3PO4
HCl
--Molecular: formula contains only
nonmetals, hydrogen is not listed first
Examples: SOCl2
C5H10
NH3
Naming Compounds
Does metal need a
roman numeral ?
No
Name the ions.
Begins with a
nonmetal and
hydrogen not first?
NoSee
other
side
YES
Ionic
Begins with a metal
or ammonium ?
No
ASK
Covalent
(Molecular)
YES
Examples:
Use T-method to
determine charge on
metal, then name ions.
AlCl3 aluminum chloride
Mg(NO3) 2 magnesium nitrate
NaH sodium hydride
NH4ClO2 ammonium chlorite
LiOH lithium hydroxide
Use prefixes to indicate
number of each
element.
Don’t start a name with
“mono”
Examples:
Examples:
CuF copper (I) fluoride
FeCO3 iron (II) carbonate
PbO2 lead (IV) oxide
Cr3(PO4)2 chromium (II) phosphate
CO2 carbon dioxide
NO nitrogen monoxide
S2P 4 disulfur tetraphosphide
CBr6 carbon hexabromide
Binary Acid:
Begin the name with “hydro”. Use the nonmetal
name’s stem, add “ic”. Include the word “acid” at
the end.
No
Acid
Contains hydrogen
and one other kind of
nonmetal?
Ternary Acid:
Contains hydrogen first and a
polyatomic ion.
Don’t start the name with “hydro”.
Change the ending on the
polyatomic ion:
ate  ic
ite  ous
Include the word “acid” at the end.
Examples:
Examples:
HCl hydrochloric acid
H2S hydrosulfuric acid
H2SO3
HClO3
H2SO2
HNO4
sulfurous acid
chloric acid
hyposulfurous acid
pernitric acid
EXCEPTION TO THIS RULE:
HCN hydrocyanic acid
ID Compounds as Ionic, Acid or Molecular
Do middle of p.1 of packet
Seven Diatomic Molecules-These are
considered “Molecular”-They make a
“seven” on the periodic table:
H2
N2 O2 F2
Cl2
Br2
I2
ID Compound as an Acid
• You will know a compound is an
acid because the formula
ALWAYS STARTS WITH a “H”
•ex: H2S=hydrosulfuric acid
•All acids will end in the word
“acid”. (ex. Hydrochloric acid)
When to include prefix “Hydro”
• You use the “Hydro” only when the formula
includes hydrogen first and one other
element. (no polyatomic)
• HCl = hydrochloric acid
• Short Formula = Long Name
• “Hydro(Insert element here)-ic Acid
When Not to Include Hydro
• No Hydro prefix is used if there is a polyatomic
Ion Present (See back of periodic table for list
of polyatomic ions)
• If the acid has a polyatomic ion in it, then
“hydro” will not be at the beginning of the
name.
•
HClO3 = chloric acid
• Long Formula = Short Name
PI’s with “–ate” and “–ite”
• When naming acids with polyatomics,
sometimes there are two ions with similar
names: Ex) Nitrate and Nitrite
• If the polyatomic ion ends in “–ate”, then
the suffix “-ic” will be added.
• Example – Nitrate  HNO3  Nitric Acid
• If the polyatomic ion ends in “–ite”, then
the suffix “-ous” will be added.
• Example – Nitrite  HNO2  Nitrous Acid
Acids: Formula -> Name
• H2S
• Polyatomic Ion? No
• the formula is “short”, so the name is
long
• Start name with “hydro-”
• What is the ending?
• Hydrosulfuric acid
Acids: Formula -> Name
• H2SO4
• Polyatomic ion? -Yes
• The formula is long, so the name is
short
• Don’t start with “hydro”
• What is the ending? “-ate”  “-ic”
• Name: Sulfuric acid
Acids: Formula -> Name
• HNO2
• Polyatomic ion?-Yes
• The formula is long, so the name is
short
• Don’t start name with “hydro”
• What is the correct ending?
• Name: Nitrous acid
Writing Formula Help
• Find oxidation numbers (charges) and
criss cross as you would with ionic
compounds.
• If name is long (includes Hydro) then it is
the element hydrogen and another
element from periodic table.
• If the name is short, you have a
polyatomic ion. Look for “ –ic” or “-ous” to
determine which polyatomic ion to use.
•
•
•
•
Phosphoric acid
Name short- formula long (polyatomic)
use oxidation numbers to get the formula
H3PO4
• Phosphorous acid
• Short name  Long formula (Polyatomic)
• H3PO3
Your Turn: Formula -> Name
• HF
• HBrO3
• H2CrO4
• H2CO3
• HClO2
Your Turn: Formula -> Name
• HF hydrofluoric acid
• HBrO3 bromic acid
• H2CrO4 chromic acid
• H2CO3 carbonic acid
• HClO2 chlorous acid
Your Turn: Name -> Formula
• Hydrosulfuric Acid
• Acetic Acid
• Hydroiodic Acid
• Phosphoric Acid
• Nitrous Acid
Your Turn: Name -> Formula
•
•
•
•
•
Hydrosulfuric Acid H2S
Acetic Acid
HC2H3O2
Hydroiodic Acid HI
Phosphoric Acid H3PO4
Nitrous Acid HNO2
Do p. 4 an 5 for homework
Types of Compounds
Three types of Compounds:
Ionic: start with a metal or ammonium
transfer of e’s, ionic bonding
Acids: Formula starts with hydrogen
--Molecular: contain only nonmetals
sharing of e’s, covalent bonding
Molecular Compounds
Electrons in a bond are shared . . .
but not always equally.
• The resulting bond is called a
covalent bond.
• Subscripts represent the actual
number(s) of each kind of atom in
the molecule.
• Molecules can be VERY large
and VERY complex, such as in
protein molecules ------------------>
is hemoglobin.
Molecular compounds are…
• made of just nonmetals
• can contain hydrogen, but it is not
written first in the formula
• smallest particle is a molecule
• Are not held together by opposite
charge attraction-they don’t contain
charged particles.
• can’t use charges to figure out how
many of each atom (there are no
charges present)
Molecular compounds are easier!
• Ionic compounds use charges to determine
subscripts
–You have to figure out charges.
–To get formula: criss-cross charges
and reduce.
– Molecular compounds: the name tells
you the number of atoms in the molecule
– Uses prefixes to tell you the exact
number of each element present!
Prefixes
Memorize These !
1 = mono2 = di3 = tri4 = tetra5 = penta-
H-6 = hexaH-7= heptaH-8 = octaH-9 = nonaH-10 = deca-
Writing Formulas for Molecular Compounds
Use prefixes to indicate the number of atoms
present.
“What you see is what you get”
Do not criss-cross anything !
The prefix “mono” is not written if there is
only one of the first element.
“Do not start a name with “mono”
Examples:
tricarbon hexafluoride =
C3F6
dinitrogen tetraoxide
= N2O4
Other rules on p.7
Write formulas for these:
•
•
•
•
•
diphosphorus pentoxide
sulfur hexafluoride
nitrogen trioxide
carbon tetrahydride
phosphorus trifluoride
Write formulas for these:
• diphosphorus pentoxide =
P2O5
• sulfur hexafluoride = SF6
• nitrogen trioxide
= NO3
• carbon tetrahydride = CH4
• phosphorus triodide = PI3
Writing Name of Molecular Compounds
To write the name:
Write name of first element include prefix if
necessary then write the name of the last
element-change the ending to “ide” and use
necessary prefix.
• Don’t start a name with “mono”
• Normally, we do not have double vowels
when writing names (oa, oo, ii)
CO2
carbon dioxide
N2S5 dinitrogen pentasulfide
Practice by naming these:
• N2O
• NO2
• Cl2O6
• SBr4
• CO2
= dinitrogen monoxide
(also called nitrous oxide or laughing gas)
= nitrogen dioxide
= dichlorine hexoxide
= sulfur tetrabromide
= carbon dioxide
Do . 8 for
homework, p. 9
is optional
extra practice
Hydrocarbons-Type of
Molecular Compound
Hydrocarbons are molecular compounds containing
only hydrogen and carbon.
An example is butane: C4H10
Hydrocarbons in which all the carbon atoms are
connected by single bonds are called
saturated hydrocarbons, also called alkanes.
Example of straight (continuous) chain alkanes:
See board- methane, ethane, propane, butane
Draw the structural formulas
Hydrocarbons
Notice the ratio of carbon atoms to hydrogen atoms
in an alkane.
The pattern can be summarized as:
_________________
Prefixes for C’s 5-10
Write the chemical formula for the other alkanes
Honors-C-5 up to C-10
CP stop after C-6
Physical Properties of Alkanes
•
• Nonpolar
• Insoluble in water.
• Lower density than water, float on water
• Low boiling and melting points.
• Flammable (undergo combustion),
producing heat.
• Gases with 1-4 carbon atoms.
(methane, propane, butane)
• Liquids with 5-16 carbon atoms.
(kerosene, diesel, and jet fuels)
• Solids with 17 or more carbon atoms.
(wax, paraffin, Vaseline)
Can dissolve many organic substances, such as
fats, oils, or waxes.
C3H8
Propane
Hydrocarbons
Isomers
Compounds that have the same molecular formula,
but different structural arrangement.(structural
formula)
Isomers have different names and are different
compounds.
Example: butane-see board
Example: pentane-has three isomers-see board
Do “More Practice”-p. 11
Do p. 12 for homwork
Naming Compounds
First identify compound as ionic, Acid or molecular, then use appropriate rules
Ionic compounds begin
with a metal, or ammonium.
Can have hydrogen written
as the second element.
To write formula: may have
to criss-cross and reduce
charges.
Acids begin with “H”
Short formula->long name
Long formula-> short name
To write formula-CC and
reduce
Molecular compounds begin
with a nonmetal and contain
only nonmetals or hydrogen
written as the second element.
To write formula: what you
see is what you get-use
prefixes. Do NOT crisscross.
Hydrocarbons: follow separate
rules for naming and writing
formulas
Do p. 14 and 15 for homework
Naming Compounds-Extra
Practice
Identify the following compounds as ionic, acid, or
molecular:
1) NaBr
2) HClO3
3) CH4
4) NH4Cl
5) NH3
6) SF6
7) sulfur trioxide
8) lithium hydroxide
9) ammonium sulfide
10) barium hydrogen carbonate
ID Compounds
Identify the following compounds as ionic or molecular:
1) NaBr ionic
2) HClO3 acid
3) CH4 molecular
4) NH4Cl ionic
5) NH3 molecular
6) SF6 molecular
7) sulfur trioxide molecular
8) lithium hydroxide ionic
9) ammonium sulfide ionic
10) barium hydrogen carbonate ionic
Naming Compounds
For 1-6 write name, for 7-10 write formula
1) NaBr ionic
2) HClO3 acid
3) CH4 molecular
4) NH4Cl ionic
5) NH3 molecular
6) SF6 molecular
7) sulfur trioxide molecular
8) lithium hydroxide ionic
9) ammonium sulfide ionic
10) barium hydrogen carbonate ionic
Naming Compounds
For 1-6 write name, for 7-10 write formula
1) NaBr ionic sodium bromide
2) HClO3 molecular chloric acid
3) CH4 molecular methane
4) NH4Cl ionic ammonium chloride
5) NH3 molecular nitrogen trihydride
6) SF6 molecular sulfur hexafluoride
7) sulfur trioxide molecular SO3
8) lithium hydroxide ionic
LiOH
9) ammonium sulfide ionic (NH4)2S
10) barium hydrogen carbonate ionic Ba(HCO3)2
All Compounds Extra Practice
ID the following as Ionic, Acid, or Molecular, then name the compound:
1) BBr3
2) CaSO4
3) C2Br6
H-4) Cr(CO3)3
5) Ag3P
6) IO2
7) HCl
8) HNO2
9) C4H10
10) N2O3
All Compounds Practice
ID the following as Ionic, Acid, or Molecular, then write the formula:
11) tetraphosphorus triselenide
12) potassium acetate
13) iron (II) phosphide
14) disilicon hexabromide
15) titanium (IV) nitrate
16) hydrofluoric acid
17) copper (I) phosphate
18) gallium oxide
19) propane
20) chromic acid
Do p. 14 and 15 for homework