Chapter 2
Atoms, Molecules, and
Ions
Chapter #2 – Atoms, Molecules and Ions
2.1 The Early History of Chemistry
2.2 Fundamental Chemical laws
2.3 Dalton’s Atomic Theory
2.4 Cannizzaro’s Interpretation
2.5 Early experiments to Characterize the Atom
2.6 The Modern View of Atomic Structure: An
Introduction
2.7 Molecules and Ions
2.8 An Introduction to the Periodic Table
2.9 Naming Simple Compounds
Computer simulation of the interior
view of a twisted nanotube.
Priestley Medal
Source: Roald Hoffman, Cornell University
Laws of Mass Conservation &
Definite Proportions (Composition)
Law of Mass Conservation:
The total mass of substances does not change
during a chemical reaction.
Law of Definite ( or constant ) Composition:
No matter what its source, a particular
chemical compound is composed of the same
elements in the same parts (fractions) by mass.
Figure 2.2: John Dalton
Source: Manchester Literary & Philosophical Society
Mass of Oxygen that Combines
with 1.00g of Carbon
Compound #1
1.33g
Compound #2
2.66g
Law of Multiple Proportions
If elements A and B react to form two compounds,
the different masses of B that combine with a fixed
mass of A can be expressed as a ratio of small whole
numbers:
Example: Nitrogen Oxides I & II
Nitrogen Oxide I : 46.68% Nitrogen and 53.32% Oxygen
Nitrogen Oxide II : 30.45% Nitrogen and 69.55% Oxygen
in 100 g of each Cpd: g O = 53.32 g & 69.55 g
g N = 46.68 g & 30.45 g
2.284
1.142
=
2
1
g O /g N =
1.142
& 2.284
Mass of Nitrogen that Combines
with 1.00g of Oxygen
I
II
II
III
I
III
Compound #1
1.750 g
Compound #2
0.8750 g
Compound #3
0.4375 g
1.750
= 0.8750
0.8750
= 0.4375
1.750
= 0.4375
=
=
=
2
1
2
1
4
1
Cpd #1
N2O
Cpd #2
NO
Cpd #3
NO2
or
NO
N4 O 2
NO2 or
N2O2
NO4
N2O4
Dalton’s Atomic Theory
Postulates:
1. Each element is made up of tiny particles called atoms.
2. The atoms of a given element are identical; the atoms
of different elements are different in some fundamental
way or ways.
3. Chemical compounds are formed when atoms combine
with each other. A given compound always has the same
relative numbers and types of atoms.
4. Chemical reactions involve reorganization of the atoms –
changes in the way they are bound together. The atoms
themselves are not changed in a chemical reaction.
Figure 2.3 (P19): Combining gases on a Molecular Level
Avogadro’s Hypothesis
At the same temperature and Pressure,
equal volumes of different gases contain
the same number of particles (Molecules).
Stanislao Cannizzaro
Source: Corbis
Cannizzaro’s Relative Atomic(Molecular)
Masses of Carbon and Hydrogen
Compound
Methane
Ethane
Propane
Butane
Carbon Dioxide
Compound
Methane
Ethane
Propane
Butane
Relative
Molecular Mass
16
30
44
58
44
Relative
Molecular Mass
16
30
44
58
Percent Carbon
by Mass
75
80
82
83
27
Percent Hydrogen
by Mass
25
20
18
17
Relative mass of
Carbon Present
12
24
36
48
12
Relative mass of
Hydrogen Present
4
6
8
10
Comparison of Several of Berzelius’s
Atomic Masses with Current Values
Element
Chlorine
Copper
Hydrogen
Lead
Nitrogen
Oxygen
Potassium
Silver
Sulfur
Atomic Mass
Berzelius’s Value
Current Value
35.41
63.00
1.00
207.12
14.05
16.00
39.19
108.12
32.18
35.45
63.55
1.01
207.2
14.01
16.00
39.10
107.87
32.07
Figure 2.4: An STM image of nickel
atoms placed on a copper surface.
Source: IBM Research
Figure 2.5: Image of a ring of cobalt
atoms placed on a copper surface.
Source: IBM Research
Figure 2.6: A cathode-ray tube. The fastmoving electrons
Figure 2.7: Deflection of cathode rays
by an applied electric field.
Figure 2.8:
(P24)
Thomson’s
Plum
Pudding
model
Figure 2.9: Schematic representation of
the apparatus Millikan
Marie
Sklodowska
Curie
Source: Corbis
Rutherford Experiment
• Alpha particles bombarding the atom.
• Rationale - to study the internal structure of the
atom, and to know more about the mass
distribution in the atom!
• Bombarded a thin Gold foil with Alpha particles
from Radium.
Figure 2.11 (P25): Rutherford’s experiment
Figure 2.12: The expected results
of the metal foil experiment
Ernest Rutherford (1871-1937)
• Won the Nobel Prize in Chemistry
in 1908
• “It was quite the most incredible
event..... It was almost as if a gunner
were to fire a shell at a piece of tissue
and the shell bounced right back!!!!! ”
Figure 2.13
(P26):
Nuclear atom
cross section
Modern Reassessment of the Atomic Theory
1. All matter is composed of atoms. Although atoms are composed
of smaller particles (electrons, protons, and neutrons), the atom
is the smallest body that retains the unique identity of the element.
2. Atoms of one element cannot be converted into atoms of another
element in a chemical reaction. Elements can only be converted into
other elements in Nuclear reactions in which protons are changed.
3. All atoms of an element have the same number of protons and
electrons, which determines the chemical behavior of the element.
Isotopes of an element differ in the number of neutrons, and thus
in mass number, but a sample of the element is treated as though
its atoms have an average mass.
4. Compounds are formed by the chemical combination of two or more
elements in specific ratios, as originally stated by Dalton.
Atomic Definitions I: Symbols, Isotopes,Numbers
A
X
Z
The Nuclear Symbol of the Atom, or Isotope
X = Atomic symbol of the element, or element symbol
A = The Mass number; A = Z + N
Z = The Atomic Number, the Number of Protons in the Nucleus
N = The Number of Neutrons in the Nucleus
Isotopes = atoms of an element with the same number of protons,
but different numbers of Neutrons in the Nucleus
Table 2.2 (P 27) The Masses and Charges of
the Electron Proton and Neutron
Particle
Mass
Charge*
Electron
9.11 x 10 – 31 kg
-1
Proton
1.67 x 10 – 27 kg
+1
Neutron
1.67 x 10 – 27 kg
none
•The magnitude of the charge on the electron and proton is
1.60 x 10-19 coulombs .
Figure 2.14(P28) Isotopes of sodium
Neutral ATOMS
•
•
51 Cr
•
•
239 Pu
•
15 N
•
•
56 Fe
= P+(26), e-(26),
N (30)
•
•
235 U
=P+(92), e-(92),
N (143)
= P+ (24), e- (24),
N (27)
= P+(94), e- (94),
N (145)
= P+(7), e-(7), N(8)
Definitions for Components of Matter
Pure Substances - Their compositions are fixed! Elements and
compounds are examples of Pure Substances.
Element - Is the simplest type of substance with unique physical and
chemical properties. An element consists of only one type
of atom. It cannot be broken down into any simpler
substances by physical or chemical means.
Molecule - Is a structure that is consisting of two or more atoms that
are chemically bound together and thus behaves as an
independent unit.
Compound - Is a substance composed of two or more elements that
are chemically combined.
Mixture - Is a group of two or more elements and/or compounds that
are physically intermingled.
Figure 2.15: Space-filling model of the
methane molecule
Figure 2.17 : Ball-and-stick model
Chemical Formulas
Empirical Formula - Shows the relative number of atoms
of each element in the compound. It is the simplest
formula, and is derived from masses of the elements.
Molecular Formula - Shows the actual number of atoms
of each element in the molecule of the compound.
Structural Formula - Shows the actual number of atoms,
and the bonds between them ; that is, the arrangement
of atoms in the molecule.
Definitions
Chemical Bonds – The forces that hold atoms together in compounds
Covalent Bonds – The sharing of electrons in a chemical bond
Molecule – A group of atoms held together by covalent bonds
Chemical Formula – The symbols of for the elements are used to
indicate the types of atoms present, and the
subscripts are used to indicate the relative
numbers of atoms present
Structural Formula – a Formula in which the bonds are shown along
with the elemental symbols and order of atom
arrangement
Chemical Compounds and Bonds
Chemical Bonds - The electrostatic forces that hold the
atoms of elements together in the compound.
Covalent Compounds - Electrons are shared between
atoms of different elements to form Covalent Cpds.
Ionic Compounds - Electrons are transferred from one
atom to another to form Ionic Cpds.
“Cations” - Metal atoms lose electrons to form “ + ” ions.
“Anions” - Nonmetal atoms gain electrons to form “ - ” ions.
Mono-atomic ions form binary ionic compounds
Molecular model: Electron transferred
from sodium to chlorine (neutral sodium to
neutral sodium ion)
Molecular model: Electron added to
chlorine (neutral chlorine to chloride ion)
Figure 2.18 : Sodium metal reacts with
chlorine gas
Figure 2.19
(P31) :
Na/Cl
arrangement
Figure 2.16 : Space-filling models
of various molecules.
Figure 2.20: Ball-and-stick models of the
ammonium ion and nitrate ion.
Definitions
• ELEMENT - A substance that cannot be separated
into simpler substances by chemical means
• COMPOUND - A substance composed of atoms
of two or more elements chemically united in
fixed proportions
• PERIODIC TABLE - “MENDELEEV TABLE” A tabular arrangement of the elements, vertical
groups or families of elements based upon their
chemical properties - actually combining ratios
with oxygen
The Periodic Table of the Elements
H
Li Be
Na Mg
He
B C N O F Ne
Al Si P S Cl Ar
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr NbMo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Rf Db Sg Bh Hs Mt Ds
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er TmYb Lu
Th Pa U Np PuAmCm Bk Cf Es FmMdNo Lr
Metals
Non Metals
Semi - metals
Metalloids
The Periodic Table of the Elements
H
Li Be
Na Mg
B C N
Al Si P
He
O F Ne
S Cl Ar
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr NbMo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Rf Db Sg Bh Hs Mt Ds
Ce Pr Nd PmSm Eu Gd Tb Dy Ho Er TmYb Lu
Th Pa U Np PuAmCmBk Cf Es FmMd No Lr
The Alkali Metals
The Halogens
The Alkaline
Earth Metals
The Noble Gases
Samples of the alkai metals
Source: Tom Pantages
Three members of the halogen family
Source: Tom Pantages
The Periodic Table of the Elements
H
Li Be
NaMg
He
B C N O F Ne
Al Si P S Cl Ar
K Ca Sc Ti V CrMn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Rf Db Sg Bh Hs Mt Ds
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np PuAmCm Bk Cf Es FmMd No Lr
Boron family
Nitrogen family
Carbon Family
Oxygen Family
The Periodic Table of the Elements
H
Li Be
Na Mg
B C N
Al Si P
He
O F Ne
S Cl Ar
K Ca Sc Ti V CrMn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr NbMo Tc Ru Rh PdAg Cd In Sn Sb Te I Xe
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Rf Db Sg Bh Hs Mt Ds
The Transition Metals
Ce Pr Nd PmSm Eu Gd Tb DyHo Er TmYb Lu
Th Pa U Np PuAmCmBk Cf Es FmMd No Lr
Lanthanides: The
Rare Earth Elements
The Actinides
Groups in the Periodic Table
Main Group Elements (Vertical Groups)
Group IA - Alkali Metals
Group IIA - Alkaline Earth Metals
Group IIIA - Boron Family
Group IVA - Carbon Family
Group VA - Nitrogen Family
Group VIA - Oxygen Family (Calcogens)
Group VIIA - Halogens
Group VIIIA - Noble Gases
Other Groups ( Vertical and Horizontal Groups)
Group IB - 8B - Transition Metals
Period 6 Group - Lanthanides (Rare Earth Elements)
Period 7 Group - Actinides
Figure 2.21: The periodic table continues
to expand as new elements are synthesized
H
Li Be
NaMg
The Periodic Table of the Elements
Date of Discovery of the Elements
He
B C N O F Ne
Al Si P S Cl Ar
K Ca Sc Ti V CrMn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Rf Db Sg Bh Hs Mt Ds
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np PuAmCm Bk Cf Es FmMd No Lr
Before 1600
1600 - 1700
1700 - 1750
1850 - 1900
1750 - 1800
1900 - 1950
1800 - 1850
1950 - 2000
H
Li Be
Na Mg
The Periodic Table of the Elements
Date of Discovery of the Elements
He
B C N O F Ne
Al Si P S Cl Ar
K Ca Sc Ti V CrMn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Rf Db Sg Bh Hs Mt Ds
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np PuAmCm Bk Cf Es FmMd No Lr
Before 1600
1700 - 1750
1850 - 1900
1600 - 1700
1750 - 1800
1900 - 1950
1800 - 1850
1950 - 2000
H
Li Be
Na Mg
The Periodic Table of the Elements
Date of Discovery of the Elements
He
B C N O F Ne
Al Si P S Cl Ar
K Ca Sc Ti V CrMn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Rf Db Sg Bh Hs Mt Ds
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np PuAmCm Bk Cf Es FmMd No Lr
Before 1600
1600 - 1700
1700 - 1750
1850 - 1900
1750 - 1800
1900 - 1950
1800 - 1850
1950 - 2000
H
Li Be
Na Mg
The Periodic Table of the Elements
Date of Discovery of the Elements
He
B C N O F Ne
Al Si P S Cl Ar
K Ca Sc Ti V CrMn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Rf Db Sg Bh Hs Mt Ds
Ce Pr Nd PmSm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np PuAmCm Bk Cf Es FmMd No Lr
Before 1600
1600 - 1700
1700 - 1750
1850 - 1900
1750 - 1800
1900 - 1950
1800 - 1850
1950 - 2000
H
Li Be
Na Mg
The Periodic Table of the Elements
Date of Discovery of the Elements
He
B C N O F Ne
Al Si P S Cl Ar
K Ca Sc Ti V CrMn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Rf Db Sg Bh Hs Mt Ds
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np PuAmCm Bk Cf Es FmMd No Lr
Before 1600
1600 - 1700
1700 - 1750
1850 - 1900
1750 - 1800
1900 - 1950
1800 - 1850
1950 - 2000
H
Li Be
Na Mg
The Periodic Table of the Elements
Date of Discovery of the Elements
He
B C N O F Ne
Al Si P S Cl Ar
K Ca Sc Ti V CrMn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Rf Db Sg Bh Hs Mt Ds
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np PuAmCm Bk Cf Es FmMd No Lr
Before 1600
1600 - 1700
1700 - 1750
1850 - 1900
1750 - 1800
1900 - 1950
1800 - 1850
1950 - 2000
H
Li Be
Na Mg
The Periodic Table of the Elements
Date of Discovery of the Elements
He
B C N O F Ne
Al Si P S Cl Ar
K Ca Sc Ti V CrMn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Rf Db Sg Bh HsMt Ds 111
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np PuAmCm Bk Cf Es FmMd No Lr
Before 1600
1600 - 1700
1700 - 1750
1850 - 1900
1750 - 1800
1900 - 1950
1800 - 1850
1950 - 2000
H
2
Li
2
Na
1
K
2
Rb
2
Cs
1
Fr
0
The Periodic Table of the Elements
Be
1
Mg
3
Ca Sc
6
1
Sr Y
4
1
Ba La
7
2
Ra Ac
0
0
Number of Stable Isotopes
Ti
5
Zr
5
Hf
6
Rf
0
Ce
4
Th
0
B
2
Al
1
V Cr Mn Fe Co Ni Cu Zn Ga
2
4
1
4
1
5
2
4
2
Nb Mo Tc Ru Rh Pd Ag Cd In
1
7
0
7
1
6 2
8
2
Ta W Re Os Ir Pt Au Hg Tl
2
5
2
7
2
6
1
7
2
Db Sg Bh Hs Mt Ds
0
0
0
0
0
0
Pr Nd Pm Sm Eu Gd Tb Dy
1
7
0
7
2
7
1
7
Pa U Np Pu Am Cm Bk Cf
0
0 0
0
0
0
0
0
C
2
Si
3
Ge
5
Sn
10
Pb
4
He
2
N
O F Ne
2
3
1
3
P
S
Cl Ar
1
4
2 3
As
Se Br Kr
1
6 2
6
Sb Te
I Xe
2 8
1
9
Bi Po
At Rn
1 0
0 0
Ho Er Tm Yb Lu
1
6
1
7
2
Es Fm Md No Lr
0
0
0
0
0
There are a Total of 282 Stable Isotopes. If we look at the even to
odd Isotopes we have a very great disparity, for odd numbered
Isotopes there are 61 stable Isotopes, or 1.45 per Z#, for even
numbered Isotopes there are 224 stable Isotopes, or 5.46 per Z#!
Newly Discovered Elements
1994
Atomic
No.
ACS Slate
IUPAC Slate
Revised
IUPAC Slate
104
105
Rutherfordium
Hahnium
Dubnium
Joliotium
Rutherfordium
Dubnium
106
Seaborgium
107
Neilsbohrium
Bohrium
Bohrium
108
Hassium
Hahnium
Hassium
109
Meitnerium
Meitnerium
Meitnerium
110
Darmstadium
Darmstadium
Darmstadium
Rutherfordium
111
?
?
GSI
112
?
?
GSI
Seaborgium
Final Slate
9/12/04
The Periodic Table of the Elements
H
Li Be
Na Mg
“1997- 2004”
He
B C N O F Ne
Al Si P S Cl Ar
K Ca Sc Ti V CrMn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Rf Db Sg Bh Hs Mt Ds
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np PuAmCm Bk Cf Es FmMd No Lr
The Periodic Table of the Elements
Most Probable Oxidation State
+1
0
+3 +_4 - 3
H +2
Li Be
B C N
+1 + 2 Al Si P
Na Mg +3 +4 +5
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi
Fr Ra Ac Rf Db Sg Bh Hs Mt Ds
+3
+3
-2 -1
He
O F Ne
S Cl Ar
Se Br Kr
Te I Xe
Po At Rn
Ce Pr Nd PmSm Eu Gd Tb Dy Ho Er TmYb Lu
Th Pa U Np Pu AmCmBk Cf Es FmMd No Lr
Table 2.3(P35) Common Monatomic
Cations and Anions
Cation
H+
Li+
Na+
K+
Cs+
Be2+
Mg2+
Ca2+
Ba2+
Al3+
Ag+
Zn2+
Name
hydrogen
lithium
sodium
potassium
cesium
beryllium
magnesium
calcium
barium
aluminum
silver
zinc
Anion
HFClBrIO2S2N3P3-
Name
hydride
fluoride
chloride
bromide
iodide
oxide
sulfide
nitride
phosphide
Table 2.4(P36) Common Type II Cations
Ion
Fe3+
Fe2+
Cu2+
Cu+
Co3+
Co2+
Sn4+
Sn2+
Pb4+
Pb2+
Hg2+
Hg22+ *
Systematic Name
Alternate Name
iron (III)
iron (II)
copper (II)
copper (I)
cobalt (III)
cobalt (II)
tin (IV)
tin (II)
lead (IV)
lead (II)
mercury (II)
mercury (I)
*Note that mercury (I) ions always occur bound together to form Hg22+
ferric
ferrous
cupric
cuprous
cobaltic
cobaltous
stannic
stannous
plumbic
plumbous
mercuric
mercurous
A dish of copper (II) sulfate.
Source: Tom Pantages
Crystals of copper (II) sulfate
Like Example 2.2 (P 37)
Give the systematic name of each of the following compounds:
a) Fe Cl3
d) B2O3
g) Na2O
b) SrF2
e) SnBr4
h) CsBr
c) MgS
f ) Ca3N2
Solution:
a) iron (III) chloride
e) Tin (IV) bromide
b) Strontium fluoride
f ) Calcium Nitride
c) Magnesium Sulfide
g) Sodium Oxide
d) Boron Oxide
h) Cesium bromide
Does the compound contain
Type I or Type II cations
Various chromium compounds
dissolved in water
Cr(NO3)3
K2Cr2O7
CrCl2
CrCl3
K2CrO4
Table 2.5 (P 38) Common Polyatomic Ions
Ion
NH4+
NO2NO3SO32SO42HSO4OHCNPO43HPO42H2PO4-
Name
Ion
ammonium
CO32nitrite
HCO3nitrate
sulfite
sulfate
ClOhydrogen sulfate
ClO2(bisulfate is a widely ClO3used common name) ClO4hydroxide
C2H3O2cyanide
MnO4phosphate
Cr2O72hydrogen phosphate CrO42dihydrogen phosphate O22-
Name
carbonate
hydrogen carbonate
(bicarbonate is a
used common name)
hypochlorite
chlorite
chlorate
perchlorate
acetate
permanganate
dichromate
chromate
peroxide
Table 2.6 (P 39)
Prefix
monoditritetrapentahexaheptaoctananadeca-
Prefixes Used to Indicate
Number in Chemical Names
Number Indicated
1
2
3
4
5
6
7
8
9
10
Figure 2.22: Flowchart for naming binary
compounds
Figure 2.23: Flowchart for overall
strategy
for naming chemical compounds
Microtaggants
Source: Microtrace, Minneapolis, MN 55449
Like Example 2.3 (P 40) Give the systematic name of
each of the following compounds
Compounds
a. Na3PO4
b. K2SO4
c. CuCO3
d. KClO4
e. KHCO3
f. Cs2SO3
g. NaIO3
h. NaOH
Names
a.
Sodium Phosphate
e. Potassium Hydrogen Carbonate
b. Potassium Sulfate
f. Cesium Sulfite
c. Copper (II) Carbonate
g. Sodium Iodate
d. Potassium Perchlorate
h. Sodium Hydroxide
Like Example 2.4 (P 42) Give the chemical formula of
each of the following compounds
Names
a.
b.
c.
d.
Sodium Peroxide
e. Lithium Hydrogen Carbonate
Chromium (VI) Oxide
f. Calcium Carbonate
Aluminum Oxide
g. Copper (II) Chloride
Ammonium Carbonate
h. Magnesium Perchlorate
Compounds
a.
Na2O2
e. LiHCO3
b. CrO3
f. CaCO3
c. Al2O3
g. Cu(Cl)2
d. (NH4)2CO3
h. Mg(ClO4)2
Naming Acids
1) Binary acids solutions form when certain gaseous compounds
dissolve in water. For example, when gaseous hydrogen chloride
(HCl) dissolves in water, it forms a solution called hydrochloric acid.
Prefix hydro- + anion nonmetal root + suffix -ic + the word acid
hydrochloric acid
2) Oxoacid names are similar to those of the oxoanions,
except for two suffix changes:
Anion “-ate” suffix becomes an “-ic” suffix in the acid. Anion “-ite”
suffix becomes an “-ous” suffix in the acid.
The oxoanion prefixes “hypo-” and “per-” are retained. Thus, BrO4is perbromate, and HBrO4 is perbromic acid; IO2- is iodite, and
HIO2 is iodous acid.
Figure 2.24(P44): Naming acids
Table 2.7 (P 44)
Acid
Names of Acids that do not
Contain Oxygen
Name
HF
hydrofluoric acid
HCl
hydrochloric acid
HBr
hydrobromic acid
HI
hydroiodic acid
HCN
hydrocyanic acid
H2 S
hydrosulfuric acid
Table 2.8 (P 44)
Acid
Names of some OxygenContaining Acids
Name
HNO3
nitric acid
HNO2
nitrous acid
H2SO4
sulfuric acid
H2SO3
sulfurous acid
H3PO4
phosphoric acid
HC2H3O2
acetic acid
Naming of the Oxoacids of Chlorine
Acid
Anion
Name
HClO4
perchlorate
perchloric acid
HClO3
chlorate
chloric acid
HClO2
chlorite
chlorous acid
HClO
hypochlorite
hypochlorous acid
Rules for Families of Oxoanions
Families with Two Oxoanions
The ion with more O atoms takes the nonmetal root and the
suffix “-ate”.
The ion with fewer O atoms takes the nonmetal root and the
suffix “-ite”.
Families with Four Oxoanions (usually a Halogen)
The ion with most O atoms has the prefix “per-”, the nonmetal
root and the suffix “-ate”.
The ion with one less O atom has just the suffix “-ate”.
The ion with two less O atoms has the just the suffix “-ite”.
The ion with three less O atoms has the prefix “hypo-” and the
suffix “-ite”.
NAMING OXOANIONS - EXAMPLES
per
hypo
Root
Suffixes
“
”
ate
“
”
ate
“
”
ite
“
”
ite
Chlorine
Bromine
Iodine
perchlorate perbromate periodate
[ ClO4-]
[ BrO4-]
[ IO4-]
No. of O atoms
Prefixes
chlorate
[ ClO3-]
bromate
[BrO3-]
iodate
[ IO3-]
chlorite
[ ClO2-]
bromite
[ BrO2-]
iodite
[ IO2-]
hypochlorite hypobromite hypoiodite
[ ClO -]
[ BrO -]
[ IO -]
Predicting the Ion an Element will form in Chemical Reactions
Problem: What monoatomic ions will each of the elements form?
(a) Barium(z=56) (b) Sulfur(z=16) (c) Titanium(z =22) (d) Fluorine(z=9)
Plan: We use the “z” value to find the element in the periodic table and
which is the nearest noble gas. Elements that lie after a noble gas will
lose electrons, and those before a noble gas will gain electrons.
Solution:
(a) Ba+2, Barium is an alkaline earth element, Group 2A, and is
expected to lose two electrons to attain the same number of electrons
as the noble gas Xenon!
(b) S -2, Sulfur is in the Oxygen family, Group 6A, and is expected to
gain two electrons to attain the same number of electrons as the noble
gas Argon!
(c) Ti+4, Titanium is in Group 4B, and is expected to lose 4 electrons
to attain the same number of electrons as the noble gas Argon!
(d) F -, Fluorine is in a halogen, Group 7A, and is expected to gain one
electron, to attain the same number of electrons as the noble gas Neon!
Give the Name and Chemical Formulas of the
Compounds formed from the following pairs
of Elements
a) Sodium and Oxygen
Na2O
Sodium Oxide
b) Zinc and Chlorine
ZnCl2
Zinc Chloride
c) Calcium and Fluorine
CaF2
Calcium Fluoride
d) Strontium and Nitrogen
Sr3N2
Strontium Nitride
e) Hydrogen and Iodine
HI
Hydrogen Iodide
f) Scandium and Sulfur
Sc2S3
Scandium Sulfide
Determining Names and Formulas of Ionic Compounds
of Elements That Form More Than One Ion.
Give the systematic names for the formulas or the formulas
for the names of the following compounds.
a) Iron III Sulfide - Fe is +3, and S is -2 therefore the compound is:
Fe2S3
b) CoF2 - the anion is Fluoride (F -1) and there are two F -1, the
cation is Cobalt and it must be Co+2 therefore the compound is:
Cobalt (II) Fluoride
c) Stannic Oxide - Stannic is the common name for Tin (IV), Sn+4, the
Oxide ion is O-2, therefore the formula of the compound is:
SnO2
d) NiCl3 - The anion is chloride (Cl-1), there are three anions, so the
Nickel cation is Ni+3, therefore the name of the compound is:
Nickel (III) Chloride
Hydrates
Compounds containing Water molecules
MgSO4
7H2O
Magnesium Sulfate heptahydrate
CaSO4
2H2O
Calcium Sulfate dihydrate
Ba(OH)2
CuSO4
Na2CO3
8H2O
5H2O
10H2O
Barium Hydroxide octahydrate
Copper II Sulfate pentahydrate
Sodium Carbonate decahydrate
Examples of Names and Formulas of
Oxoanions and Their Compounds - I
• KNO2
Potassium Nitrite
• Mg(NO3)2 Magnesium Nitrate
• LiClO4 Lithium Perchlorate
BaSO3 Barium Sulfite
Na2SO4 Sodium Sulfate
Ca(BrO)2 Calcium Hypobromite
• NaClO3 Sodium Chlorate
Al(IO2)3 Aluminum Iodite
• RbClO2 Rubidium Chlorite
KBrO3 Potassium Bromate
• CsClO
Cesium Hypochlotite
LiIO4 Lithium Periodate
Examples of Names and Formulas of
Oxoanions and their Compounds - II
• Calcium Nitrate Ca(NO3)2
• Strontium Sulfate SrSO4
• Potassium Hypochlorite KClO
• Rubidium Chlorate
RbClO3
• Ammonium Chlorite NH4ClO2
• Sodium Perchlorate NaClO4
Ammonium Sulfite
Lithium Nitrite
(NH4)2SO3
LiNO2
Lithium Perbromate
LiBrO4
Calcium Iodite
Ca(IO2)2
Boron Bromate
B(BrO3)3
Magnesium Hypoiodite Mg(IO)2
Determining Names and Formulas of Ionic
Compounds Containing Polyatomic Ions
a) BaCl2 5 H2O
Ba+2 is the cation Barium, Cl- is the Chloride
anion. There are five water molecules therefore
the name is: Barium Chloride Pentahydrate
b) Magnesium Perchlorate Magnesium is the Mg+2 cation, and
perchlorate is the ClO4- anion, therefore we need
two perchlorate anions for each Mg cation
therefore the formula is: Mg( ClO4)2
c) (NH4)2SO3
NH4+ is the ammonium ion, and SO3-2 is the
sulfite anion, therefore the name is:
Ammonium Sulfite
d) Calcium Nitrate Calcium is the Ca+2 cation, and nitrate is the
NO3- anion, therefore the formula is:
Ca(NO3)2
Determining Names and Formulas of
Anions and Acids
Problem: Name the following anions and give the names and
a) I -
formulas of the acid solutions derived from them:
b) BrO3c) SO3-2 d) NO3- e) CN -
Solution:
a) The anion is Iodide; and the acid is Hydroiodic acid, HI
b) The anion is Bromate; and the acid is Bromic acid, HBrO3
c) The anion is Sulfite; and the acid is Sulfurous acid, H2SO3
d) The anion is Nitrate; and the acid is Nitric acid, HNO3
e) The anion is Cyanide; and the acid is Hydrocyanic acid, HCN
Determining Names and Formulas of Binary
Covalent Compounds
Problem: What are the name or Chemical formulas of the following
Chemical compounds:
a) Carbon dioxide b) PCl3 c) Give the name and chemical formula
of the compound formed from two P atoms and five O atoms.
Solution:
a) The prefix “di-” means “two.” The formula is CO2
b) P is the symbol for phosphorous; there are three chlorine atoms
which require the prefix “tri-.” The name of the compound is:
phosphorous trichloride
c) P comes first in the name (lower group number). The compound is
diphosphorous pentaoxide
( commonly called “phosphorous pentaoxide”)
Calculating the Molecular Mass of a Compound
Problem: Using the data in the periodic table, calculate the molecular
mass of the following compounds:
a) Tetraphosphorous decoxide b) Ammonium sulfate
Plan: We first write the formula, then multiply the number of atoms
(or ions) of each element by its atomic mass, and find the sum.
Solution:
a) The formula is P4O10.
Molecular mass = (4 x atomic mass of P ) +(10 x atomic mass of O )
= ( 4 x 30.97 amu) + ( 10 x 16.00 amu)
= 283.88 = ___________amu
b) The formula is (NH4)2SO4
Molecular mass = ( 2 x atomic mass of N ) + ( 8 x atomic mass of H)
+ ( 1 x atomic mass of S ) + ( 4 x atomic mass of O)
= ( 2 x 14.01 amu) + ( 8 x 1.008 amu) +
( 1 x 32.07 amu) + ( 4 x 16.00 amu)
= 132.154 amu = ____________ amu
Calculate the Molecular Mass of
Glucose: C6H12O6
• Carbon
6 x 12.01 g/mol =
72.06 g
• Hydrogen 12 x 1.008 g/mol = 12.096 g
• Oxygen
6 x 16.00 g/mol =
96.00 g
g
A space-filled model of C60
containing
a "caged" methanol molecule
Source: Photo Researchers