CHEMISTRY 161

1
CHEMISTRY 161 Chapter 3
2
1. Structure of an Atom
subatomic particles
electrons (cloud)
neutrons (nucleus)
protons (nucleus)
m(n) / m(e) 2000
m(n) gt m(p)
3
2. Atomic Mass Number
mass number (number of protons plus neutrons)
atomic number (number of protons) (number of
electrons)
4
Compounds Chemical Reactions

• Compounds
• 2. The Chemical Formula
• 3. The Chemical Equation
• 4. The Name of Chemicals

5
1. Compounds
molecular compounds
ionic compounds
EXPI
6
Molecular Compounds
1. consist of electrically neutral particles
called molecules
2. each molecule consists of atoms
3. atoms are connected via electrons
4. connections are called bonds (springs)
EXPII
7
Molecular Compounds
Group
Period IVA VA
VIA VIIA Noble Gas 2
CH4 NH3 H2O HF
Ne 3 SiH4 PH3 H2S
HCl Ar 4 GeH4 AsH3
H2Se HBr Kr 5
SbH3 H2Te HI Xe
lots of molecules contain hydrogen
EXPIII
8
Jupiter
H2, He
CH4
PH3
EXPIV
9
Saturn
H2O (s)
H2, He
CH4
NH3/PH3
10
Ionic Compounds I
1. consist of charged particles
2. charged particles are called ions
3. ions are formed by electron transfers from
atoms
atom (neutral)
take electron(s) (oxidation)
add electron(s) (reduction)
cation(Na) (positive charge) (metal)
anion(Cl-) (negative charge) (non-metal)
11
Ionic Compounds II
4. ionic compounds are held together by
electrostatic forces
non-metal
metal
NaCl
MgO
EXPV
12
Compounds Chemical Reactions
1. Compounds 2. The Chemical Formula 3. The
Chemical Equation 4. The Name of Chemicals
13
2. The Chemical Formula
collection of chemical symbols used to describe
the composition of elements and compounds
NaCl
H2O
Fe2O3
CaSO4 ? 2 H2O
14
2. The Chemical Formula
collection of chemical symbols used to describe
the composition of elements and compounds
EXPVI
15
F2
EXPVII
16
O2
17
S8
18
N2
19
P4
20
H2
21
Compounds Chemical Reactions
1. Compounds 2. The Chemical Formula 3. The
Chemical Equation 4. The Name of Chemicals
22
3. The Chemical Equation
chemical equation describes what happens in a
chemical reaction
chemical reaction is combination of elements
and/or compounds
?
H2 O2 H2O
2
2
balancing mass conservation
23
3. The Chemical Equation
2 H2 O2 ? 2 H2O
s solid l liquid g gas aq
aqueous solution
2 H2(g) O2 (g) ? 2 H2O (l)
24
Examples

1. phosphor with oxygen

2. sulfur with oxygen
3. methane with oxygen
25
Compounds Chemical Reactions
1. Compounds 2. The Chemical Formula 3. The
Chemical Equation 4. The Name of Chemicals
26
Organic Compounds
compounds containing mostly hydrogen and
carbon minor amount other elements (N, O, S, P)
hydrocarbons
H
C
alkanes
CnH2n2
27
Organic Compounds?
CO2
H2CO
C4H10
CO
H2O
C4H10 combustion
EXPVIII
28
Titan Saturns Largest Moon
29
Cassini-Huygens Mission
30
Cassini-Huygens Mission
31
Inorganic Compounds
binary compounds
compounds consisting of ONLY TWO different
elements
NaCl
CO2
CaSO4
naming compounds
nomenclature
nomen (Latin) name
32
Metal (Main Group) Non-Metal
part one (metal)
part two
English name of element
stem ide
NaCl
MgO
BeS
symbol stem first element
second element O ox-
oxygen oxide S
sulf- sulfur sulfide
N nitr- nitrogen
nitride P phosph- phosphorus
phosphide F fluor-
fluorine fluoride Cl
chlor- chlorine chloride
Br brom- bromine
bromide I iod- iodine
iodide
33
Nomenclature Inorganic Compounds
main group metal
stem ide
element
ionic compounds (metal non-metal)
34
Nomenclature Inorganic Compounds
main group metal
stem ide
element
ionic compounds (metal non-metal)
molecular compounds
prefix stem ide
prefix element
35
Molecular Compounds
PF3
PF5
CO
CO2
HCl
N2O5
NO
NO2
Greek Prefixes
mono- 1 (often omitted) hexa- 6
di- 2
hepta- 7 tri- 3
octa- 8 tetra-
4 nona- 9
penta- 5 deca-
10
36
Nomenclature Inorganic Compounds
main group metal
stem ide
element
ionic compounds (metal non-metal)
trans. group metal
oxstate
stem ide
element
FeO
Fe2O3
molecular compounds
stem ide
prefix element prefix
37
ionic compounds
cations anions
compounds must be electrically neutral
Mn
Em-
nonmetals
metals transition metals
charge state of ions
38
-/ 3/5
-/ 2/4
-2
-1
0
1
2
3
CaCl2
K2S
main group metals always start with cation
39
oxidation states
NiCl2
CuO
CuCl
Mn2O3
B2O3
transition metals always start with anions
40
molecular compounds
ionic compounds
polyatomic ionic compounds
ammonium chloride
sodium dichromate
magnesium carbonate
rubidium sulfate
calcium phosphate
41
Nomenclature Inorganic Compounds
main group metal
stem ide
element
ionic compounds (metal non-metal)
trans. group metal
oxstate
stem ide
element
molecular compounds
stem ide
prefix element prefix
42
Mass Percentage Composition
P4O10

X 100

X 100
43

• Example
• A sample was analyzed and contains 0.1417 g of
  nitrogen and 0.4045 g of oxygen.
• Calculate the percentage composition.

X 100
1. mass of whole sample
2. percentages of elements
44
MOLECULAR FORMULA
H2O
EMPIRICAL FORMULA
H2O2
HO
H2O
H2O
P2O5
P4O10
P22O25
45

• Example
• A sample contains 0.522 g of nitrogen and 1.490
  g of oxygen. Calculate its empirical formula.

N2O5
46
COMBUSTION
CxHy
CO2
H2O
EXPIX
47
COMBUSTION
C3H8
H2O
O2
CO2
0.013068 g
How many grams of oxygen are consumed?

1. balance equation
2. convert to moles

48

• The combustion of a 5.217 g sample of a compound
  of C, H, and O gave 7.406 g CO2 and 4.512 g of
  H2O.
• Calculate the empirical formula of the compound.
  

How many grams of Al2O3 are produced when 41.5 g
Al react? 2Al(s) Fe2O3(s) Al2O3(s) 2
Fe(s)
49
Compounds Chemical Reactions

• Compounds
• 2. The Chemical Formula
• 3. The Chemical Equation
• 4. The Name of Chemicals

50
Nomenclature Inorganic Compounds
main group metal
stem ide
element
ionic compounds (metal non-metal)
trans. group metal
oxstate
stem ide
element
molecular compounds
stem ide
prefix element prefix