Chem A Naming Polyatomic Ions
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Chemistry A
Naming
Polyatomic Ions
Chem A Naming Polyatomic Ions
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Worksheet #1: Introduction to Polyatomic Ions
So far we have only learned how to name compounds with two different elements. The first type of
compound we named was an ionic compound. Ionic compounds are made of a metal and a nonmetal. The
second type of compound we named was a covalent compound. Covalent compounds are made of two
nonmetals.
In this packet we will learned how to name compounds with more than two elements. In all the
examples we will look at, these compounds will contain a polyatomic ion. A polyatomic ion is a group of
atoms that has a charge (by the loss or gain of electrons). It sticks together as a single unit in chemical
reactions.
The following table contains the common polyatomic ions we will use. You do not need to memorize
these, but you will need to be able to use them to write formulas and name compounds.
Cation with +1 charge
Formula
Name
+1
NH4
ammonium
Anions with -1 charge
Formula
Name
-1
C2H3O2 acetate
OH-1
hydroxide
-1
ClO4
perchlorate
ClO3-1
chlorate
-1
ClO2
chlorite
ClO-1
hypochlorite
NO3-1
nitrate
-1
NO2
nitrite
BrO3-1 bromate
IO3-1
iodate
CN-1
cyanide
-1
SCN
thiocyanate
MnO4-1 permanganate
HCO3-1 bicarbonate
or hydrogen carbonate
HSO4-1 bisulfate
or hydrogen sulfate
H2PO4-1
dihydrogen
phosphate
Anions with -2 charge
Formula
Name
-2
CO3
carbonate
SO4-2
sulfate
SO3-2
sulfite
S2O3-2
thiosulfate
-2
SiO3
silicate
O2-2
peroxide
CrO4-2
chromate
-2
Cr2O7
dichromate
HPO4-2
biphosphate
or hydrogen phosphate
C2O4-2
oxalate
Anions with -3 charge
Formula
Name
-3
AsO4
arsenate
BO3-3
borate
-3
PO3
phosphite
PO4-3
phosphate
Notice that with the exception of ammonium (NH4+1), all the other polyatomic ions have a negative
charge. Because of this, they usually take the place of the nonmetal in the compound and bond with a metal. For
example:
calcium carbonate
Ca+2
and
CO3-2 =
CaCO3
When writing formulas you treat polyatomic ions as just like single atoms. If you need more than one of the
polyatomic ions, you put it in parenthesis and use a subscript. For example:
calcium nitrate
Ca+2
and
NO3-1
= Ca(NO3)2
ammonium sulfate
NH4+1 and
SO4-2
= (NH4)2SO4
Chem A Naming Polyatomic Ions
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Worksheet # 2: Naming Polyatomic Ions
When naming polyatomic compounds you just need to name each ion. You can use the chart to help you. For
example:
Ba(C2H3O2)2
= barium acetate
Al(ClO3)3
= aluminum chlorate
Write the names of the following compounds.
Formula
Name
Formula
CaCO3
Cs2SiO3
Ni(ClO2)2
RbC2H3O2
KHCO3
Be(BrO3)2
CdSO4
Na3BO3
Al(H2PO4)3
BaO2
NaClO
KMnO4
FrOH
Ag2SiO3
Name
Write the formulas for the following compounds. The oxidation #’s for the polyatomic ions are on the chart.
Name
Symbol
w/ ox #
Formula
(Swap & Drop)
Name
magnesium hydroxide
silver carbonate
aluminum nitrate
ammonium phosphate
lithium sulfate
barium hydroxide
sodium bicarbonate
zinc nitrite
calcium phosphite
potassium dichromate
zinc acetate
aluminum silicate
lithium peroxide
beryllium perchlorate
Symbol
w/ ox #
Formula
(Swap & Drop)
Write the correct name for the following compounds and then tell the number of atoms present in each of the
following formulas.
Formula
Name
# of atoms
NaHSO4
(NH4)2CO3
Ba(C2H3O2)2
Mg3(PO4)2
Chem A Naming Polyatomic Ions
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Chem A Naming Polyatomic Ions
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Chem A Naming Polyatomic Ions
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Worksheet # 3: Naming Polyatomic Ions with Metals that have Multiple Oxidation Numbers
The following compounds contain one of the seven metals, which have more than one oxidation number.
They are iron, copper, mercury, tin, lead, antimony and bismuth.
If you are to name compounds using roman numerals you will need to calculate the oxidation number of
the compound. For example:
 you have tin(II) carbonate
SnCO3 
+2
Sn
Fe(SCN)3 
+3
Fe (SCN)3-1(3) = -3
(CO3)-2(1) = -2
 you have iron(III) thiocyanate
Name the following compounds using the Stock Method.
Formula
Calculation
Name
Hg(NO3)2
Sb(ClO4)5
Pb(C2H3O2)2
CuClO2
Bi2(SiO3)5
Sn(HPO4)2
FeCO3
Cu(CN)2
Sb2(SO4)3
Pb(NO2)2
Sn(OH)2
Hg2(ClO3)2
Fe2(S2O3)3
BiPO3
Write the formulas for the following compounds.
Name
Symbol
w/ ox #
Formula
Name
lead(II) nitrate
tin(IV) phosphate
copper(II) carbonate
mercury (I) silicate
iron (III) hydroxide
tin (II) iodate
antimony(III) acetate
iron(II) thiosulfate
lead (IV) cyanide
antimony(V)oxalate
copper (I) chlorite
mercury(II) sulfate
bismuth (III) bisulfate
bismuth (V)chromate
Symbol
w/ ox #
Formula
Chem A Naming Polyatomic Ions
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Chem A Naming Polyatomic Ions
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Worksheet # 4: Review of Naming Polyatomic Ions
This worksheet is a combination of worksheet # 2 and # 3. You will need to decide when to use roman
numerals.
Name the following compounds. Use the roman numerals when appropriate.
Formula
Name
Formula
SbPO4
Pb(C2H3O2)2
LiBrO3
Fr2SiO3
Na2O2
CaC2O4
SnSO4
KSCN
(NH4)3BO3
Mg3(AsO4)2
Be(ClO2)2
Sb(NO2)5
NH4OH
Bi2(SiO3)3
Name
Write the formula for the following compounds.
Name
Symbol
w/ ox #
Formula
Name
potassium cyanide
rubidium hypochlorite
ammonium hydroxide
copper (I) nitrate
lead(II) chromate
lithium arsenate
magnesium oxalate
sodium borate
mercury (II) chlorate
iron(III) thiocyanate
calcium oxalate
antimony (III) bromate
barium sulfate
copper(II) carbonate
Symbol
w/ ox #
Formula
Write the correct name for the following compounds and then tell the number of atoms present in each of the
following formulas.
Formula
Name
# of atoms
(NH4)3PO4
Al(ClO4)3
Fe2(SO4)3
K3AsO4
Sb(OH)5
Chem A Naming Polyatomic Ions
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Worksheet # 5: Review of Regular Compounds AND Polyatomic Compounds (All Types of Compounds)
Give the name for the following ionic compounds containing metals and nonmetals. Use roman numerals when appropriate.
Formula
Name
Formula
Name
NaCl
AlN
K 2S
Sr3P2
PbO
BiF5
Give the formula for the following compounds containing metals and nonmetals.
Name
Symbol
w/ ox #
Formula
Name
copper (I) chloride
cesium phosphide
barium bromide
rubidium telluride
antimony(III) sulfide
aluminum oxide
Symbol
w/ ox #
Formula
Name the following covalent compounds containing all nonmetals. Remember to use prefixes.
Formula
Name
Formula
P4O10
Cl2O7
PF3
BI3
N2O
SO2
Name
Write the formula for the following compounds.
Name
Formula
Name
carbon monoxide
sulfur hexafluoride
sulfur trioxide
silicon tetrachloride
diphosphorus trioxide
nitrogen monoxide
Formula
Name the following compounds. This is a mixture of all of the types of compounds you have learned so far.
Formula
Name
Formula
Name
Li3N
Al2(CO3)3
NH4OH
NiF2
SiO2
PCl3
MgSO4
Zn(C2H3O2)2
Write the formula for the following compounds. This is a mixture of all of the types of compounds you have learned so far.
Name
Symbol
Formula
Name
Symbol
Formula
w/ ox #
w/ ox #
(Optional)
(Optional)
beryllium silicate
ammonium thiocyanate
tetraphosphorus hexasulfide
sodium cyanide
iron(II) selenide
nitrogen trichloride
mercury (I) biphosphate
silver nitrate
Chem A Naming Polyatomic Ions
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Worksheet #6- Final Review of Binary Compounds AND Polyatomic Ions (All Types of Compounds)
Write the name, symbol, and oxidation numbers for the seven elements, which require the use of roman
numerals.
Multiple Oxidation
Symbol
Lower Oxidation #
Higher Oxidation #
Number Metal
Write the first 10 prefixes.
1=
3=
5=
7=
9=
2=
6=
8=
10=
4=
Write the name for the following compounds. Use roman numerals for compounds containing the multiple
oxidation number metals. Use prefixes for compounds containing all nonmetals.
Formula
Name
Formula
Name
(NH4)2SO4
Fe(BrO3)3
NO3
P2O4
Hg2S
BaHPO4
PtO
PbC2O4
CsNO3
AlCl3
Write the formula for the following compounds.
Name
Symbol
Formula
w/ ox #
(Optional)
beryllium hydroxide
dinitrogen tetraoxide
strontium nitride
ammonium cyanide
antimony (V) chlorate
carbon dioxide
sulfur hexafluoride
sodium hypochlorite
dinitrogen monoxide
bismuth (III) fluoride
Name
Symbol
w/ ox #
(Optional)
Formula