• There is a systematic process in the
naming of inorganic acids. Probably the
most significant problem is the variation of
oxidation numbers for the negative ions.
• For example
Cl-1
NO3-1
SO4-2
PO4-3
chloride ion
nitrate ion
sulfate ion
phosphate ion
• Another significant problem is that many of
the other polyatomic ions with the same
endings on their names have a different
number of oxygen atoms attached to the
central atom.
• For example
chlorate
sulfate
phosphate
acetate
ClO3-1
SO4-2
PO4-3
C2H3O2-1
• Rather than memorize all the polyatomic
Ions it is much more useful to learn their
trends in the naming scheme. There are
numerous patterns within a homologous
series.
• For example
» ClO4-1
» ClO3-1
» ClO2-1
» ClO-1
» Cl-1
perchlorate
chlorate
chlorite
hypochlorite
chloride (not a polyatomic ion)
AllAll
the
the
names
ions
contain
chlor
indicating
atom
All
havecontain
a minusone
onechlorine
charge
but
a varying
number
of oxygen atoms
that the
ion
contains
chlorine
The oxy-ions of chlorine, bromine and
iodine all have these trends in common.
Look for them below……
perchlorate
chlorate
chlorite
hypochlorite
ClO4-1
ClO3-1
ClO2-1
ClO-1
Perbromate
Bromate
Bromite
Hypobromite
BrO4-1
BrO3-1
BrO2-1
BrO-1
Periodate
Iodate
Iodite
Hypoiodite
IO4-1
IO3-1
IO2-1
IO-1
The most productive method of committing
these ions to memory is first memorize the
ones that have the _____ate ending. . This
is the most common ending.
POLYATOMIC IONS
Ions with -1
perbromate
bromate
bromite
hypobromite
perchlorate
chlorate
chlorite
hypochlorite
periodate
iodate
iodite
hypoiodite
charge
BrO4-1
BrO3-1
BrO2-1
BrO-1
ClO4-1
ClO3-1
ClO2-1
ClO-1
IO4-1
IO3-1
IO2-1
IO-1
nitrate
nitrite
hydroxide
cyanide
thiocyanate
acetate
permanganate
bicarbonate
NO3-1
NO2-1
OH-1
CN-1
SCN-1
C2H3O2-1
MnO4-1
HCO3-1
Ions with a -2 Charge
carbonate
CO3-2
phthalate
C8H4O4-2
sulfate
SO4-2
sulfite
chromate
dichromate
oxalate
peroxide
SO3-2
CrO4-2
Cr2O7-2
C2O4-2
O2-2
Ions with a -3 Charge
phosphate
PO4-3
phosphite
PO3-3
arsenate
AsO4-3
Ions with +1 charge
ammonium ion NH4+1
The table below shows the prefixes and suffixes
that tell the number of oxygen atoms present in the
negative ion.
Salt
metal
polyatomic ion
# Oxygen
atoms
________
per_____ate
4
________
_____ate
3
________
_____ite
2
________ hypo_____ite
1
________
0
_____ide
REMEMBER
the aqueous acid names are simply an
extension of the salt names.
Salt
metal
Aqueous Acid
polyatomic ion
hydrogen
polyatomic ion
________
per_____ate
per_____ic acid
________
_____ate
_____ic acid
________
_____ite
_____ous acid
________ hypo_____ite
hypo______ous acid
________
_____ide
hydro______ic acid
To transform the metal per____ate salt into its
corresponding aqueous acid name:
1) The name of the metal is dropped
2) The -ate ending is replaced with –ic
3) The word acid is added to the name
For example:
potassium perchlorate > perchloric acid
KClO4(s) > HClO4 (aq)
Salt
metal
Aqueous Acid
polyatomic ion
hydrogen
polyatomic ion
________
per_____ate
per_____ic acid
________
_____ate
_____ic acid
________
_____ite
_____ous acid
________ hypo_____ite
hypo______ous acid
________
_____ide
hydro______ic acid
To transform the metal _____ate salt into its
corresponding aqueous acid name:
1) The name of the metal is dropped
2) The -ate ending is replaced with –ic
3) The word acid is added to the name
For example:
sodium acetate > acetic acid
NaC2H3O2(s) > HC2H3O2(aq)
Salt
metal
Aqueous Acid
polyatomic ion
hydrogen
polyatomic ion
________
per_____ate
per_____ic acid
________
_____ate
_____ic acid
________
_____ite
_____ous acid
________ hypo_____ite
hypo______ous acid
________
_____ide
hydro______ic acid
To transform the metal_____ite salt into its
corresponding aqueous acid name:
1) The name of the metal is dropped
2) The -ite ending is replaced with –ous
3) The word acid is added to the name
For example:
ammonium nitrite > nitrous acid
NH4NO2(s) > HNO2(aq)
Salt
metal
Aqueous Acid
polyatomic ion
hydrogen
polyatomic ion
________
per_____ate
per_____ic acid
________
_____ate
_____ic acid
________
_____ite
_____ous acid
________ hypo_____ite
hypo______ous acid
________
_____ide
hydro______ic acid
To transform the metal hypo_____ite salt into its
corresponding aqueous acid name:
1) The name of the metal is dropped
2) The -ite ending is replaced with –ous
3) The word acid is added to the name
For example:
lithium hypoiodite > hypoiodous acid
LiIO (s) > HIO (aq)
Salt
metal
Aqueous Acid
polyatomic ion
hydrogen
polyatomic ion
________
per_____ate
per_____ic acid
________
_____ate
_____ic acid
________
_____ite
_____ous acid
________ hypo_____ite
hypo______ous acid
________
_____ide
hydro______ic acid
To transform the metal _____ide salt into its
corresponding aqueous acid name:
1) The name of the metal is dropped
2) The -ide ending is replaced with hydro____ic
3) The word acid is added to the name
For example:
silver bromide > hydrobromic acid
AgBr(s) > HBr(aq)
The following exercises will deal
only with the names and formulas
of aqueous acids. The names and
formulas for the salts were studied
in detail in a previous lesson.
Example #1-Names to Formulas
chloric acid
1. Determine the formula &
charge of the polyatomic ion
2. Add hydrogen ions
3. Balance charge with ions
4. Add the subscript: (aq)
chlorate
+1
H
-1 =0
ClO3 (aq)
Final Formula
Examples #1-
Formulas to Names
HBrO2(aq)
1. The hydrogen out front &
the (aq) subscript indicates
an acid
2. Determine the ion and it’s
acid ending.
bromite
bromous
____________
acid
Final Name
Examples #10-
Formulas to Names
HBrO2(aq)
1. The hydrogen out front &
the (aq) subscript indicates
an acid
2. Determine the ion and it’s
acid ending.
bromite
bromous
____________
acid
Final Name
Practice Problem #1
HIO4(aq)
Choose the correct name for the compound
1. iodic acid
2. iodous acid
3. periodic acid
4. hydrogen periodate
5. none of the above
Ion list
next problem
Practice Problem #2
hydrobromic acid
Choose the correct formula for the compound
1. HBrO(aq)
2.
HBr(aq)
3. HBrO3(aq)
4. HBrO2(aq)
5. none of the above
Ion list
next problem
POLYATOMIC IONS
Ions with -1
perbromate
bromate
bromite
hypobromite
perchlorate
chlorate
chlorite
hypochlorite
periodate
iodate
iodite
hypoiodite
charge
BrO4-1
BrO3-1
BrO2-1
BrO-1
ClO4-1
ClO3-1
ClO2-1
ClO-1
IO4-1
IO3-1
IO2-1
IO-1
nitrate
nitrite
hydroxide
cyanide
thiocyanate
acetate
permanganate
bicarbonate
NO3-1
NO2-1
OH-1
CN-1
SCN-1
C2H3O2-1
MnO4-1
HCO3-1
Ions with a -2 Charge
carbonate
CO3-2
phthalate
C8H4O4-2
sulfate
SO4-2
sulfite
chromate
dichromate
oxalate
peroxide
SO3-2
CrO4-2
Cr2O7-2
C2O4-2
O2-2
Ions with a -3 Charge
phosphate
PO4-3
phosphite
PO3-3
arsenate
AsO4-3
Ions with +1 charge
ammonium ion NH4+1
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