Molecules and Compounds:
Nomenclature
Compounds vs. Elements
Compound 1: Table Salt
Properties: Soluble crystals, stable,
edible
Elements (Components)
• Sodium – shiny, reactive, poisonous
• Chlorine – pale yellow gas, reactive,
poisonous
Compound 2: Table sugar
Properties: sweet, soluble crystal
Elements (Components) :
• Carbon – pencil or diamonds
• Hydrogen – flammable gas
• Oxygen – a gas in air
2
Law of Constant Composition
Pure substances have constant composition
 all samples of a pure substance contain the same elements in
the same percentages (ratios): Water (H: 11%, O: 89%),
Table salt (Na: 39%, Cl: 61%), Sugar
 mixtures have variable composition: Air, Seawater, Concrete,
Rocky road ice cream, Coke
3
Why do Compounds Show
Constant Composition
• the smallest piece of a compound is
called a molecule: Water molecule,
Sugar molecule
• every molecule of a compound has the
same number and type of atoms.
Water molecule: 2 Hydrogen atom + 1
Oxygen atom;
Sugar molecule: 12 Carbon atom + 22
Hydrogen atom + 11 Oxygen atom
 every sample of the compound will have
the same ratio of the elements
4
Chemical Formula
Chemical formula: describe the compound by
describing the number and type of each atom in the
simplest unit of the compound
 molecules or ions (Table salt: Cl+, Na-)
• Element represented by its letter symbol: H instead
of hydrogen; Na instead of Sodium
• #Atoms of each element: the right of the element as a
subscript, H2O (unless if there is only one atom, the 1
subscript is not written)
• Polyatomic groups (multiple atoms in group,
example: CO3) are placed in parentheses if more than
one
5
From Composition
to Chemical Formula
water = H2O \ two atoms of
hydrogen and 1 atom of oxygen
table sugar = C12H22O11 \12 atoms
of C, 22 atoms of H and 11 atoms O
6
Classifying Pure
Substances
Element
• Atomic: consists of single atoms
(Metals, Noble gases)
• Molecular: consists of multi-atom
molecules (O2, N2, Cl2, etc)
Compound
• Molecular: consists of molecules
made of only nonmetals (CO2, H2O)
• Ionic: consists of cations (Na+) and
anions (Cl-)
7
Elements and Compounds
8
Classify each of the following:
Element atomic/molecular
Compound  molecular/ionic
•
•
•
•
•
•
aluminum, Al = atomic element
aluminum chloride, AlCl3 = ionic compound
chlorine, Cl2 = molecular element
acetone, C3H6O = molecular compound
carbon monoxide, CO = molecular compound
cobalt, Co = atomic element
9
Molecular Elements
Certain elements occur as 2 atom molecules
• Rule of 7’s
 there are 7 common diatomic elements
 find the element with atomic number 7, N
 make a figure 7 by going over to Group 7A, then down
 don’t forget to include H2
VIIA
H2
N2
7
O2
F2
Cl2
Br2
I2
10
Molecular Elements
= Metal
= Metalloid
H
= Nonmetal
N O F
Cl
Br
I
Molecular Compounds
• two or more nonmetals
• smallest unit is a
molecule
• Common examples: H2O
• CO2 (as in soda and dry
ice)
• NH3 (as in Windex),
• Table sugar C11H22O11
12
Ionic Compounds
Ions: Metals (Cation Mx+)
and Nonmetals (Anion
Ny-)
• No individual molecules!!
• have a 3-dimensional
array of cations and
anions made of formula
units: NaCl, MgO
• Na+ Cl- Na+ Cl- Na+ Cl• Cl- Na+ Cl- Na+ Cl- Na+
• Na+ Cl- Na+ Cl- Na+ Cl-
13
Binary Molecular Compounds:
Two Nonmetals (such as CO2)
1. Name first element in formula first
 use the full name of the element
2. Name the second element in the formula with an -ide
 as if it were an anion, however, remember these compounds
do not contain ions!
3. Use a prefix in front of each name to indicate the
number of atoms
a) Never use the prefix mono- on the first element
14
Subscript - Prefixes
• 1 = mono-;
not used on first
nonmetal
• 2 = di• 3 = tri• 4 = tetra-
•
•
•
•
•
5 = penta6 = hexa7 = hepta8 = octadrop last “a” if
name begins with
vowel
15
Exceptions when Naming
Molecular Compounds
of course, water 
Other common exceptions:
• NH3: ammonia (as in Windex)
• H2S: hydrogen sulfide
• HCl: hydrogen chloride (same for HX, where X =
halogen)
• CH4: methane (as in natural gas)
• H2O2: hydrogen peroxide
16
Example – Naming Binary Molecular
BF3
1. Is it one of the common exceptions?
H2O, NH3, CH4, C12H22O11 = No!
2. Identify Major Class
B = is a nonmetal because it is on the right side of the PT
F = is a nonmetal because it is on the right side of the PT
\ Molecular
3. Identify the Subclass
2 elements \ Binary Molecular
17
Example – Naming Binary Molecular
BF3
4. Name the first element
boron
5. Name the second element with an –ide
fluorine  fluoride
6. Add a prefix to each name to indicate the subscript
monoboron, trifluoride
7. Write the first element with prefix, then the second
element with prefix
 Drop prefix mono from first element
boron trifluoride
18
Practice:
Naming Molecular Compounds
•
•
•
•
•
•
•
CO
ClO3
SO2
P2O5
N2O4
IF7
SF6
19
Key to Naming Molecular Compounds
•
•
•
•
•
•
•
CO
ClO3
SO2
P2O5
N2O4
IF7
SF6
carbon monoxide
chlorine trioxide
sulfur dioxide
diphosphorus pentoxide
dinitrogen tetroxide
iodine heptoxide
sulfur hexafluoride
20
Ionic Compounds
• Made of Cation (+) and Anion (-)
• Name: Cation Anion
example: NaCl Sodium Chloride
Cation:
Type I metal
Type II metal
Polyatomic ion: ammonium NH4+
Anion:
Nonmetal: Chloride Cl-, Oxide O2Polyatomic ion: SO42- , OH- , NO321
Metal Cations: Type I
Type I (Groups IA, IIA, AZA)
only have one possible charge
Groups IA, IIA, Ag+, Zn2+, Al3+
Charge by position on the Periodic
Table
IA = +1, IIA = +2,
Ag+ (IB), Zn2+(IIB) Al3+(IIIA)
How do you know a
metal cation is Type II?
its not Type I !!!
22
Metal Cations: Type II
Type II: Metal ions that are
other than Type I
Common Examples: Fe2+/3+,
Cu+/2+, Cr3+/6+, Mn2+/4+,
Mn2+/4+, Pb2+/4+, Sn2+/4+, etc )
have more than one possible
charge
determine charge by charge on
anion
How do you know a
metal cation is Type II?
its not Type I !!!
23
Metal Cations: Type I vs. Type II
= Type I Metal
= Type II Metal
Al
Zn
Ag
Monatomic Nonmetal Anion (An-)
• How much is the charge? the position on the
Periodic Table
• Name of the anion: change ending on the
element name to –ide
4A = -4
5A = -3
6A = -2
7A = -1
C4- = carbide
N3- = nitride
O2- = oxide
F- = fluoride
Si4- = silicide
P3- = phosphide
S2- = sulfide
Cl- = chloride
25
Net charge of Ionic Compound
=0
• Net charge = Positive charge from cation(s)
+ Negative charge from Anion(s) = 0
• Example: Compound Al2(SO4)3, the Net
charge = 2 x (+3) + 3 x (-2) = +6 - 6 = 0
26
Name of Ionic Compounds
• Name: Cation Anion: Sodium Chloride
 Cation:
Type I metal = metal name : Na+ => Sodium, Mg2+ =>
Magnesium
Type II metal = metal name(charge): Fe3+ Iron(III), Cu2+
Copper(II)
Polyatomic ion = name of polyatomic ion, NH4+ =>
Ammonium
 Anion:
Nonmetal = stem of nonmetal name + ide, Chloride, Oxide
Polyatomic ion = name of polyatomic ion, SO42- => Sulfate,
OH- => Hydroxide, NO3- => Nitrate
27
Type I Binary Ionic Compounds
Binary: only two kinds of ions in one UNIT
Example: MgO, CaCl2
• Metal listed first in formula & name
1. Metal Cation  Nonmetal Anion
2. Cation name <= Metal name: Magnesium,
Calcium
3. Nonmetal anion <= Nonmetal name ends with
–ide: Oxide, Chloride
28
Example – Naming Binary Ionic, Type I Metal
CsF
1. Is it one of the common exceptions?
H2O, NH3, CH4, C12H22O11  No!
2. Identify Major Class
Cs = is a metal because it is on the left side of the PT
F = is a nonmetal because it is on the right side of the PT
 Ionic
3. Identify the Subclass
2 elements, \ Binary Ionic
4. Is the metal Type I or Type II
Cs is in Group IA, \ Type I
29
Example – Naming Binary Ionic, Type I Metal
CsF
5. Identify cation and anion
Cs = Cs+ because it is Group 1
F = F- because it is Group 7
6. Name the cation
Cs+ = cesium
7. Name the anion
F- = fluoride
8. Full name: Cation name first, Anion name last
cesium fluoride
30
Type II Binary Ionic Compounds
Metal listed first in formula & name
1. Metal cation  Nonmetal anion
2. metal cation  Metal(Roman Numeral): to indicate
its charge. Iron(II), Copper(I)
 determine charge from anion charge
 Common Type II cations in Table 5.5
3. Nonmetal anion  Nonmetal name ended with –ide:
Chloride, Oxide
Example: Iron(II) chloride, Copper(I) oxide
31
How to find the charge on Type II
metal ions?
• Example: Name Compound Fe2(SO4)3
Since the sum of all charges equals zero, the charge
on iron ions are unknown and sulfate each has –2
charge, then we have
2 x Fe + 3 x (-2) = 0
Fe = +3, each iron ion has a charge of +3
Name: iron(III) sulfate
Key: knowing the charge on ANIONs!
32
Example – Naming Binary Ionic, Type II Metal
CuCl
1. Is it one of the common exceptions?
H2O, NH3, CH4, C12H22O11 = No!
2. Identify Major Class
Cu = is a metal because it is on the left side of the PT
Cl = is a nonmetal because it is on the right side of the PT
\ Ionic
3. Identify the Subclass
2 elements, \ Binary Ionic
4. Is the metal Type I or Type II
Cu is not in Group IA, IIA, or (Al, Ga, In) \ Type II
33
Example – Naming Binary Ionic, Type II Metal
CuCl
5. Identify cation and anion
Cl = Cl- because it is Group 7
Cu = Cu+ to balance the charge
6. Name the cation
Cu+ = copper(I)
7. Name the anion
Cl- = chloride
8. Write the cation name first, then the anion name
copper(I) chloride
34
Practice: Naming Ionic compounds
•
•
•
•
•
•
•
HgF2
CuI2
CaCl2
Fe2O3
SnCl4
Mg3N2
Ag2S
35
Naming Ionic compounds
Hints: find type II ion charge from anion
•
•
•
•
•
•
•
HgF2 : Two F- = -2
Hg = +2
CuI2 : Two I- = -2Cu
-2 = +2
CaCl2 : both fixed charges
Fe2O3 : Three O2- = -6 Fe = +3
SnBr4 : Four Br- = -4
Sn = +4
Mg3N2 : both fixed charges
Ag2S : both fixed charges
36
Answer key: names of ionic
compounds
•
•
•
•
•
•
•
HgF2 = Mercury(II) fluoride
CuI2 = copper(II) iodide
CaCl2 = calcium chloride
Fe2O3 = Iron(III) oxide
SnBr4 = tin(IV) bromide
Mg3N2 = magnesium nitride
Ag2S = silver sulfide
37
Polyatomic Ions
symbol of the polyatomic
ion called nitrate
symbol of the polyatomic
ion called sulfate
Mg(NO3)2
CaSO4
compound called
magnesium nitrate
compound called
calcium sulfate
implied “1” subscript
on magnesium
parentheses to group two NO3’s
implied “1” subscript
on calcium
no parentheses for one SO4
38
Polyatomic Ions:
Nitrate NO3-, Sulfate SO42subscript indicating
two NO3 groups
no subscript indicating
one SO4 group
Mg(NO3)2
CaSO4
compound called
magnesium nitrate
compound called
calcium sulfate
implied “1” subscript
on nitrogen, total 2 N
stated “3” subscript
on oxygen, total 6 O
implied “1” subscript
on sulfur, total 1 S
stated “4” subscript
on oxygen, total 4 O
39
Polyatomic Anions: -ATE ions
CO32-
NO3-
carbonate
nitrate
SiO32-
PO43-
SO42-
ClO3-
silicate
phosphate
sulfate
chlorate
AsO43-
SeO42-
BrO3-
arsenate
selenate
bromate
IO3iodate
40
Periodic Pattern of Polyatomic Ions
-ate groups
IIIA
3BO3
IVA
VA
VIA
VIIA
2CO3
NO3
2SiO3
3PO4
2SO4
ClO3
3AsO4
2SeO4
BrO3
2TeO 4
IO3
41
Patterns for Polyatomic Ions
1. elements in the same Group form similar
polyatomic ions
 same number of O’s and same charge
ClO3- = chlorate (-1 charge)
BrO3- = bromate (-1 charge)
2. if the polyatomic ion starts with H, the name adds
hydrogen- prefix before name and add 1 to the
charge
CO32- = carbonate \ HCO3-1 = hydrogen carbonate
42
Patterns for Polyatomic Ions
-ate ion
chlorate = ClO3-
• -ate ion + 1 O  same charge, per- prefix
perchlorate = ClO4-
• -ate ion – 1 O  same charge, -ite suffix
chlorite = ClO2-
• -ate ion – 2 O  same charge, hypo- prefix,
-ite suffix
hypochlorite = ClO43
Polyatomic Anions:
-ite, hypo- -ite, (-ate), per- -ate
ClOhypochlorite
NO2-
PO33-
SO32-
ClO2-
nitrite
phosphite
sulfite
chlorite
NO3-
PO43-
SO42-
ClO3-
nitrate
phosphate
sulfate
chlorate
ClO4perchlorate44
-ATE/-ITE ions in Our Lives
ClO(bleach)
NO2-
PO33-
SO32-
ClO2-
(preserve meat)
(plant medicine)
(wine, oxygen
buster)
(bleach, disinfect)
NO3-
PO43-
SO42-
ClO3-
(plaster, car
battery, sea salt)
(older pyrotechnics)
(fertilizer, explosives) (bone/teeth, fertilizer,
soda)
ClO4(pyrotechnics, solid
fuel rocket) 45
Polyatomic Ions to Remember
Name
Formula
Name
Formula
acetate
C2H3O2–
hypochlorite
ClO–
carbonate
CO32–
chlorite
ClO2–
chlorate
ClO3–
perchlorate
ClO4–
sulfate
SO42–
HSO4–
hydrogen carbonate
(aka Bicarbonate)
HCO3
hydroxide
OH–
nitrate
NO3–
nitrite
NO2–
Hydrogen sulfate
(aka Bisulfate)
permanganate
MnO4–
sulfite
SO32–
chromate
CrO42–
Hydrogen sulfite
(aka Bisulfite)
HSO3–
cyanide
CN–
dichromate
Cr2O7
ammonium
NH4+
–
2–
46
Other Polyatomic Ions in Our
Lives
C2H3O2–
In vinegar as acetic acid
CO32–
Soda drink
HCO3–
Baking soda, baking power, acid spill
neutralizer
OH–
In liquid plumber/Drano as NaOH
MnO4–
Disinfectant, “aging” for movie making
CrO42–
Chrome plating (faucet, etc.)
CN–
Highly Poisonous; Plant seeds; blue
pigment
NH4+
Fertilizer; metabolic waste from animals
47
Other Polyatomic Ions in Our
Lives
ClO(bleach)
NO2-
PO33-
SO32-
ClO2-
(preserve meat)
(plant medicine)
(wine, oxygen
buster)
(bleach, disinfect)
NO3-
PO43-
SO42-
ClO3-
(plaster, car
battery, sea salt)
(older pyrotechnics)
(fertilizer, explosives) (bone/teeth, fertilizer,
soda)
ClO4(pyrotechnics, solid
fuel rocket) 48
Compounds Containing
Polyatomic Ions
•
•
•
•
Type I metal + Polyatomic ion: NaNO3
Type II metal(charge) + Polyatomic ion : CuSO4
Polyatomic cation + Nonmetal ion (-ide): NH4Cl
Polyatomic cation + Polyatomic ion: (NH4)2SO4
Important!: If, and only if, more than ONE polyatomic
ions are present in a formula, use parenthesis and
subscript to indicate the number of polyatomic ions
49
Example – Naming Ionic with Polyatomic Ion
Na2SO4
1. Is it one of the common exceptions?
H2O, NH3, CH4, C12H22O11 = No!
2. Identify Major Class
Na = is a metal because it is on the left side of the PT
SO4 = is a polyatomic ion
\ Ionic
3. Identify the Subclass
compound has 3 elements \ Ionic with Polyatomic Ion
4. Is the metal Type I or Type II
Na is in Group IA, \ Type I
50
Example – Naming Ionic with Polyatomic Ion
Na2SO4
5. Identify the ions
Na = Na+ because in Group 1
SO4 = SO42- a polyatomic ion
6. Name the cation
Na+ = sodium (Type I)
7. Name the anion
SO42- = sulfate
8. Write the name of the cation followed by the
name of the anion
sodium sulfate
51
Example – Naming Ionic with Polyatomic Ion
Fe(NO3)3
1. Is it one of the common exceptions?
H2O, NH3, CH4, C12H22O11 = No!
2. Identify Major Class
Fe = is a metal because it is on the left side of the PT
NO3 = is a polyatomic ion because it is in ( )
\ Ionic
3. Identify the Subclass
there are 3 elements \ Ionic with Polyatomic Ion
4. Is the metal Type I or Type II
Fe is not in Group IA, IIA, or (Al, Ga, In) \ Type II
52
Example – Naming Ionic with Polyatomic Ion
Fe(NO3)3
5. Identify the ions
NO3 = NO3- a polyatomic ion
Fe = Fe+3 to balance the charge of the 3 NO3-1
6. Name the cation
Fe+3 = iron(III) (Type II)
7. Name the anion
NO3- = nitrate
8. Write the name of the cation followed by the
name of the anion
iron(III) nitrate
53
Practice: Naming Ionic compounds
•
•
•
•
•
•
•
Hg2SO4
CuClO3
Zn(NO3)2
FeCO3
Sn(SO3)2
CoPO4
Al(ClO4)3
54
Hints: Naming Ionic compounds
•
•
•
•
•
•
•
Hg2SO4 : charge of sulfate = -1
CuClO3 : charge of chlorate = -1
Zn(NO3)2 charge of nitrate = -1
FeCO3 : charge of carbonate = -2
Sn(SO3)2: charge of sulfite = -1
CoPO4 : charge of phosphate = -3
Al(ClO4)3 : charge of perchlorate = -1
55
Keys: Naming Ionic compounds
•
•
•
•
•
•
•
Hg2SO4 : mercury(I) sulfate
CuClO3 : copper(I) chlorate
Zn(NO3)2 zinc nitrate
FeCO3 : iron(II) carbonate
Sn(SO3)2: tin(IV) sulfite
CoPO4 : cobalt(III) phophate
Al(ClO4)3 : aluminum perchlorate
56
Acids
• Contain H+ cation and
anion
• Hydrogen (H) as first
element in formula
• Binary acids (HnX) have
H+ cation and nonmetal
anion
• Oxyacids (HnXOm) have
H+ cation and polyatomic
anion
57
Naming Acids
All names have acid at end
• Binary Acids (HnX) = hydro prefix + stem of the
name of the nonmetal + ic suffix
Example: HCl (Hydrochloric acid)
• Oxyacids (HnXOm : H2CO3 , H2SO4)
 if polyatomic ion ends in –ate = name of polyatomic
ion with –ic suffix :
H2SO4 (Sulfuric acid); H2CO3 (Carbonic acid);
HNO3 (Nitric acid);
H3PO4 (Phosphoric acid)
 if polyatomic ion ends in –ite = name of polyatomic ion
with –ous suffix
58
Naming Binary Acids – HF
1. First of all, it is binary acid HX
2. Identify the anion
F  F-, fluoride because Group 7A
2. Name the anion with an –ic suffix
F- = fluoride  fluoric
3. Add a hydro- prefix to the anion name
hydrofluoric
4. Add the word acid to the end
hydrofluoric acid
59
Naming Oxyacids: H2SO4
1. Identify the anion
SO4 = SO42- = sulfate
2. If the anion has –ate suffix, change it to –ic. If the anion
has –ite suffix, change it to -ous
SO42- = sulfate  sulfuric
3. Write the name of the anion followed by the word acid
sulfuric acid
(kind of an exception, to make it sound nicer!)
60
Practice: Naming Acids
first: what is the anion?
•
•
•
•
•
•
•
HNO3
HClO3
HBr
H2CO3
H2SO3
H3PO4
HClO4
nitrate
chlorate
bromide
carbonate
sulfite
phosphate
perchlorate
61
Practice: Naming Acids
•
•
•
•
•
•
•
HNO3 nitrate  nitric acid
HClO3 chlorate  chloric acid
HBr
bromide  hydrobromic acid
H2CO3 carbonate  carbonic acid
H2SO3 sulfite  sulfurous acid
H3PO4 phosphate  phosphoric acid
HClO4 perchlorate  perchloric acid
62
Formula-to-Name Flow Chart
63
Review: Naming Compounds
•
•
•
•
•
•
•
•
CuSO3
AgClO
N2O5
H2S
FeI2
Sn(NO3)4
Ba3(PO4)2
(NH4)2S
1. Common exceptions?
H2O, NH3, CH4, C12H22O11
2. Identify as Molecular
or Ionic?
3. Identify
•
•
Binary molecular
Type I or II metal ion
64
Review: Naming Compounds
•
•
•
•
•
•
•
•
CuSO3
AgClO
N2O5
H2S
FeI2
Sn(NO3)4
Ba3(PO4)2
(NH4)2S
copper(II) sulfite
silver hypochlorite
dinitrogen pentoxide
hydrosulfuric acid
iron(II) iodide
tin(IV) nitrate
barium phosphate
ammonium sulfide
65
Write Chemical Formula using
the charge of known ions
• Example: Compound between Ca2+ and
PO43- , the number of ions of each needs to
be 3 and 2, so that the combined charge
= 3 x (+2) + 2 x (-3) = 0
Therefore the formula for the compound is
Ca3(PO4)2
66
Write Chemical Formula using
the charge of known ions
“Criss-Cross-Simplify”:
• The charge of an ion turns into the subscript (the
number) of the counterpart ion
Pb4+ O2-
 Pb2O4
• Since the subscripts in an ionic compound
represents the RATIO among the ions, the
subscripts need to be simplified when there is
common denominator
Pb2O4  PbO2
67
Practice: Writing formulas (I)
•
•
•
•
•
•
•
copper(II) chloride
aluminum oxide
magnesium phosphide
iron(II) bromide
lead(II) sulfide
zinc iodide
sodium nitride
68
Hints for Writing formulas (I):
Charges on Cations and Anions
•
•
•
•
•
•
•
copper(II) chloride:
Cu2+ and Claluminum oxide:
Al3+ and O2magnesium phosphide : Mg2+ and P3iron(II) bromide :
Fe2+ and Brlead(II) sulfide :
Pb2+ and S2zinc iodide :
Zn2+ and Isodium nitride :
Na+ and N369
Key for Writing formulas (I):
use criss-cross-reduce
•
•
•
•
•
•
•
copper(II) chloride
aluminum oxide
magnesium phosphide
iron(II) bromide
lead(II) sulfide
zinc iodide
sodium nitride
CuCl2
Al2O3
Mg3P2
FeBr2
FeS
ZnI2
Na3N
70
Practice: Write Chemical Formulae
•
•
•
•
•
•
•
Chromium(II) Chloride
Cesium phosphate
Lead(II) oxide
Zinc nitrate
Iron(III) sulfite
Strontium nitride
Ammonium carbonate
71
Key: Write Chemical Formulae
•
•
•
•
•
•
•
Chromium(II) Chloride
Cesium phosphate
Lead(II) oxide
Zinc nitrate
Iron(III) sulfite
Strontium nitride
Ammonium carbonate
CrCl2
Cs3PO4
PbO
Zn(NO3)2
Fe3(SO3)2
Sr3N2
(NH4)2CO3
72
Practice: Writing formulas (I)
•
•
•
•
•
•
•
•
copper(I) sulfate
aluminum chlorate
magnesium phosphate
iron(II) carbonate
lead(II) acetate
zinc sulfite
sodium nitrite
Nitrogen gas
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Hints for Writing formulas (I):
Charges on Anions
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copper(I) sulfate: -2 for sulfate
aluminum chlorate: -1 for chlorate
magnesium phosphate: -3 for phosphate
iron(II) carbonate : -2 for carbonate
lead(II) acetate: -1 for acetate
zinc sulfite : -2 for sulfite
sodium nitrite: -1 for nitrite
Nitrogen gas: atomic or molecular element?
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Key: Writing formulas (I)
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copper(I) sulfate:
Cu2SO4
aluminum chlorate:
Al(ClO3)3
magnesium phosphate:
Mg3(PO4)2
iron(II) carbonate :
FeCO3
lead(II) acetate:
Pb(C2H3O2)2
zinc sulfite :
ZnSO3
sodium nitrite:
NaNO2
Nitrogen gas:
N2
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More on Writing formulae
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copper(II) sulfate
aluminum perchlorate
hydroiodic acid
iron(III) bromide
Diphosphorus pentoxide
lead(IV) nitride
zinc carbonate
helium gas
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Key: Writing formulae
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copper(II) sulfate
CuSO4
aluminum perchlorate Al(ClO4)3
hydroiodic acid
HI
iron(III) bromide
FeBr3
Diphosphorus pentoxide
P2O5
lead(IV) nitride
Pb3N4
zinc carbonate
ZnCO3
ammonium nitrite
NH4NO2
helium gas
He
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