Chemical Composition of the World: Atoms 101 ???? “indivisible

Transcription

Atoms, Molecules and Ions
Chemistry 120
Chemical Composition of the World: Atoms 101
???? “indivisible, uncuttable”
All matter is composed of atoms which cannot be
further split into smaller portions
Atoms are completely solid
Atoms are homogeneous,
with no internal structure
Between atoms there is empty space
Atoms differ in size
Democritus (c.460 -c.370 B.C.)
Chemistry 120
John Dalton (1766 -1844)
Chemistry 120
Thomson’s
“blueberry muffin” model
Electrons embedded in a
shell of positive charge
Rutherford’s model
Electrons randomly
circulating around nucleus
made of protons
1
Chemistry 120
The Modern Atom
Au foil
Most of the atom is empty
space.
Atomic radius = ~ 10-10 m
Nuclear radius = ~ 10-15 m
Volume ratio:
?
VAtom : VNucleus = ~ 1015
The Modern Atom
Chemistry 120
The atom is made up of
three fundamental particles
The proton, p +
}Nuclear
The neutron, n 0
The electron, e-
Most of the mass of the
atom is contained in the
nucleus
Nucleus
The Modern Atom
Mass/kg
Charge*
Chemistry 120
proton
neutron
1.67x10 -27
1.675x10-27
+1
0
electron
9.1x10 -31
-1
Location
Nucleus
Nucleus
Atom
Stability
Stable
Unstable
outside the
nucleus
Stable
* In units of 1.6 x 10 -19 C
2
The Modern Atom - Structure
Chemistry 120
A Small Dense Nucleus
Nuclear Radius: ~ 10-15 m (1 fm)
Density of the nucleus:
~ 100,000,000,000,000 gcm-3
Density of water = 1 gcm-3
The mass of the electron is ~ 1/2000 that of the
proton and neutron – most of the mass of the atom
is in the nucleus
The Four Forces of Nature
Chemistry 120
There are only four fundamental forces found in
Nature.
Two are macroscopic
- gravity
- electromagnetism
Two are microscopic
- strong nuclear force
- weak nuclear force
The Four Forces of Nature
Chemistry 120
Two are very weak and are not important for the
structure of the atom
- gravity
- weak nuclear force
Two bind the atom together
- strong nuclear force
- electromagnetism
3
Chemistry 120
Structure of the nucleus not well understood:
Particles all interact with each other
Chemistry 120
Internal constituents of the protons and
neutrons interact
Chemistry 120
neutrons interact
Nuclear force, the strong nuclear force, not
well understood
4
Chemistry 120
neutrons interact
Nuclear force, the strong nuclear force, not
well understood
Very high energies needed for study
Chemistry 120
Structure of the atom is well understood:
Electrons flow around the nucleus
Chemistry 120
Bound to the central positive nucleus by the
electromagnetic force:
5
Chemistry 120
Opposite Charges Attract
Chemistry 120
Opposite Charges Attract
Experimentally easy energies needed for
study
Chemistry and the Modern Atom
Chemistry 120
Atoms bind together using their electrons
Chemistry is based in the physics of electrons
in atoms
We understand electrons in atoms well
enough to understand chemistry at a high
level
6
The Chemical Atom
Chemistry 120
Atoms are neutral – they have no electrical charge
There are equal numbers of protons in the nucleus
and electrons in the atom.
The charges on the electron and the proton are
equal.
The Chemical Atom
Chemistry 120
Atomic numbers and mass numbers
The chemistry of each element is determined by the
number and energy of the outer valence electrons.
The atom is neutral and so the number of protons
equals the number of electrons.
The Atomic Number, Z, shows number of protons
in the nucleus.
The Chemical Atom
Chemistry 120
The order of the elements in the periodic table is in
the order of increasing number of protons in the
nucleus and therefore electrons in the atom.
The mass number is the atomic mass and we write
an element as AZ X
where X is the chemical symbol, A is the
mass number and Z is the atomic number.
4
2
He
7
Chemistry 120
For Helium, He,
Mass = 4
Atomic number = 2
}
4
2
He
Isotopes
Chemistry 120
The number of protons determines the chemical
identity of the element.
The number of neutrons in the nucleus does not
affect the number of electrons and therefore the
chemical identity.
Atoms which have different numbers of neutrons
and the same number of protons are called
Isotopes
The mass of an atom A is given by
Chemistry 120
A=Z+N
Number of protons
Number of neutrons
Isotopes have different masses but are chemically
identical
58 Ni
16 O
60 Ni
17 O
68.27
26.1
61 Ni
1.13
62 Ni
3.59
64 Ni
0.91
18 O
99.762
0.038
0.2
8
Chemistry 120
To calculate the natural mass of the element,
multiply the abundance of the isotope by the mass
of the isotope and add:
58 Ni
68.27
26.1
61 Ni
1.13
62 Ni
3.59
64 Ni
0.91
60 Ni
Chemistry 120
58 Ni
68.27%
26.1%
61 Ni
1.13%
62 Ni
3.59%
64 Ni
0.91%
60 Ni
58 x 68.27/100 =
60 x 26.1/100 =
61 x 1.13/100 =
62 x 3.59/100 =
64 x 0.91/100 =
Chemistry 120
58 Ni
68.27%
26.1%
61 Ni
1.13%
62 Ni
3.59%
64 Ni
0.91%
60 Ni
58 x 68.27/100 = 39.5966
60 x 26.1/100 = 15.66
61 x 1.13/100 = 0.6893
62 x 3.59/100 = 2.2258
64 x 0.91/100 = 0.5824
9
Chemistry 120
58 Ni
68.27%
26.1%
61 Ni
1.13%
62 Ni
3.59%
64 Ni
0.91%
60 Ni
58 x 68.27/100 = 39.5966
60 x 26.1/100 = 15.66
61 x 1.13/100 = 0.6893
62 x 3.59/100 = 2.2258
64 x 0.91/100 = 0.5824
58.7541
The Periodic Table
Chemistry 120
The Periodic Table is an ordered array of the
elements, with rising atomic number.
First written down by Dimitri
Mendeléev as a list of the
elements with increasing atomic
Mass. The elements naturally
grouped themselves by chemical
properties.
s block
1
H
1
Building the Periodic Table
Dimitri Mendeléev
(1834 – 1907)
Chemistry 120
p block
He
2
10
s block
1
H
1
2
Li
3
Chemistry 120
p block
He
2
Be
4
B
5
C
6
O
8
F
9
Ne
10
Chemistry 120
s block
N
7
p block
1
H
1
2
Li
3
Be
4
B
5
C
6
N
7
O
8
F
9
He
2
Ne
10
3
Na
11
Mg
12
Al
13
Si
14
P
15
S
16
Cl
17
Ar
18
The Periodic Table
s block
1
Chemistry 120
p block
H
1
He
2
2
Li
3
Be
4
3
Na
11
Mg
12
4
K
19
Ca
20
d block
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
Zn
30
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
Ar
18
Ga
31
Ge
32
As
33
Se
34
Br
35
Kr
36
11
Chemistry 120
The Periodic Table
s block
p block
1
H
1
2
Li
3
Be
4
He
2
3
Na
11
Mg
12
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
Ag
47
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
Kr
36
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
Xe
54
d block
Chemistry 120
The Periodic Table
s block
p block
1
H
1
2
Li
3
Be
4
He
2
3
Na
11
Mg
12
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
6
Cs
55
Ba
56
Lu
71
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
Pt
78
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
Kr
36
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
Xe
54
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
Rn
86
d block
f block
La
57
Ce
58
Pr
59
Nd
60
Pm
61
Sm
62
Eu
63
Gd
64
Tb
65
Dy
66
Ho
67
Er
68
Yb
70
Chemistry 120
The Periodic Table
s block
1
Tm
69
p block
H
1
He
2
2
Li
3
Be
4
3
Na
11
Mg
12
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
Kr
36
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
6
Cs
55
Ba
56
Lu
71
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
Xe
54
Pt
78
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
7
Fr
86
Ra
88
Lr
103
Rf
104
Db
105
Sg
106
Bh
107
Hs
108
Mt
109
Rn
86
110
111
112
d block
f block
La
57
Ce
58
Pr
59
Nd
60
Pm
61
Sm
62
Eu
63
Gd
64
Tb
65
Dy
66
Ho
67
Er
68
Tm
69
Yb
70
Ac
89
Th
90
Pa
91
U
92
Np
93
Pu
94
Am
95
Cm
96
Bk
97
Cf
98
Es
99
Fm
100
Md
101
No
102
12
Chemistry 120
The S block
s block
p block
1
H
1
2
Li
3
Be
4
He
2
3
Na
11
Mg
12
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
6
Cs
55
Ba
56
Lu
71
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
7
Fr
86
Ra
88
Lr
103
Rf
104
Db
105
Sg
106
Bh
107
Hs
108
Mt
109
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
Kr
36
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
Xe
54
Pt
78
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
Rn
86
110
111
112
d block
f block
La
57
Ce
58
Pr
59
Nd
60
Pm
61
Sm
62
Eu
63
Gd
64
Tb
65
Dy
66
Ho
67
Er
68
Tm
69
Yb
70
Ac
89
Th
90
Pa
91
U
92
Np
93
Pu
94
Am
95
Cm
96
Bk
97
Cf
98
Es
99
Fm
100
Md
101
No
102
Chemistry 120
The S block and P block
s block
p block
1
H
1
2
Li
3
Be
4
He
2
3
Na
11
Mg
12
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
6
Cs
55
Ba
56
Lu
71
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
7
Fr
86
Ra
88
Lr
103
Rf
104
Db
105
Sg
106
Bh
107
Hs
108
Mt
109
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
Kr
36
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
Xe
54
Pt
78
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
Rn
86
110
111
112
d block
f block
La
57
Ce
58
Pr
59
Nd
60
Pm
61
Sm
62
Eu
63
Gd
64
Tb
65
Dy
66
Ho
67
Er
68
Tm
69
Yb
70
Ac
89
Th
90
Pa
91
U
92
Np
93
Pu
94
Am
95
Cm
96
Bk
97
Cf
98
Es
99
Fm
100
Md
101
No
102
The S block , P block
s block
1
Chemistry 120
H
1
p block
He
2
and D block
2
Li
3
Be
4
3
Na
11
Mg
12
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
Kr
36
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
6
Cs
55
Ba
56
Lu
71
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
Xe
54
Pt
78
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
7
Fr
86
Ra
88
Lr
103
Rf
104
Db
105
Sg
106
Bh
107
Hs
108
Mt
109
Rn
86
110
111
112
d block
f block
La
57
Ce
58
Pr
59
Nd
60
Pm
61
Sm
62
Eu
63
Gd
64
Tb
65
Dy
66
Ho
67
Er
68
Tm
69
Yb
70
Ac
89
Th
90
Pa
91
U
92
Np
93
Pu
94
Am
95
Cm
96
Bk
97
Cf
98
Es
99
Fm
100
Md
101
No
102
13
Chemistry 120
The S block , P block ,
s block
p block
1
H
1
2
Li
3
Be
4
He
2
3
Na
11
Mg
12
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
6
Cs
55
Ba
56
Lu
71
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
7
Fr
86
Ra
88
Lr
103
Rf
104
Db
105
Sg
106
Bh
107
Hs
108
Mt
109
D block and F block
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
Kr
36
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
Xe
54
Pt
78
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
Rn
86
110
111
112
d block
f block
La
57
Ce
58
Pr
59
Nd
60
Pm
61
Sm
62
Eu
63
Gd
64
Tb
65
Dy
66
Ho
67
Er
68
Tm
69
Yb
70
Ac
89
Th
90
Pa
91
U
92
Np
93
Pu
94
Am
95
Cm
96
Bk
97
Cf
98
Es
99
Fm
100
Md
101
No
102
Chemistry 120
The Radioactive elements
s block
1
H
1
2
Li
3
Be
4
3
Na
11
Mg
12
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
6
Cs
55
Ba
56
Lu
71
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
7
Fr
86
Ra
88
Lr
103
Rf
104
Db
105
Sg
106
Bh
107
Hs
108
Mt
109
p block
He
2
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
Kr
36
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
Xe
54
Pt
78
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
Rn
86
110
111
112
d block
f block
La
57
Ce
58
Pr
59
Nd
60
Pm
61
Sm
62
Eu
63
Gd
64
Tb
65
Dy
66
Ho
67
Er
68
Tm
69
Yb
70
Ac
89
Th
90
Pa
91
U
92
Np
93
Pu
94
Am
95
Cm
96
Bk
97
Cf
98
Es
99
Fm
100
Md
101
No
102
Gases at room temperature
s block
1
Chemistry 120
p block
H
1
He
2
2
Li
3
Be
4
3
Na
11
Mg
12
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
Kr
36
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
6
Cs
55
Ba
56
Lu
71
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
Xe
54
Pt
78
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
7
Fr
86
Ra
88
Lr
103
Rf
104
Db
105
Sg
106
Bh
107
Hs
108
Mt
109
Rn
86
110
111
112
d block
f block
La
57
Ce
58
Pr
59
Nd
60
Pm
61
Sm
62
Eu
63
Gd
64
Tb
65
Dy
66
Ho
67
Er
68
Tm
69
Yb
70
Ac
89
Th
90
Pa
91
U
92
Np
93
Pu
94
Am
95
Cm
96
Bk
97
Cf
98
Es
99
Fm
100
Md
101
No
102
14
Chemistry 120
Gases and liquids at room
temperature
s block
1
H
1
2
Li
3
Be
4
3
Na
11
Mg
12
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
6
Cs
55
Ba
56
Lu
71
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
7
Fr
86
Ra
88
Lr
103
Rf
104
Db
105
Sg
106
Bh
107
Hs
108
Mt
109
p block
He
2
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
Kr
36
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
Xe
54
Pt
78
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
Rn
86
110
111
112
d block
f block
La
57
Ce
58
Pr
59
Nd
60
Pm
61
Sm
62
Eu
63
Gd
64
Tb
65
Dy
66
Ho
67
Er
68
Tm
69
Yb
70
Ac
89
Th
90
Pa
91
U
92
Np
93
Pu
94
Am
95
Cm
96
Bk
97
Cf
98
Es
99
Fm
100
Md
101
No
102
Chemistry 120
The Non-metals
s block
p block
1
H
1
2
Li
3
Be
4
He
2
3
Na
11
Mg
12
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
6
Cs
55
Ba
56
Lu
71
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
7
Fr
86
Ra
88
Lr
103
Rf
104
Db
105
Sg
106
Bh
107
Hs
108
Mt
109
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
Kr
36
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
Xe
54
Pt
78
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
Rn
86
110
111
112
d block
f block
La
57
Ce
58
Pr
59
Nd
60
Pm
61
Sm
62
Eu
63
Gd
64
Tb
65
Dy
66
Ho
67
Er
68
Tm
69
Yb
70
Ac
89
Th
90
Pa
91
U
92
Np
93
Pu
94
Am
95
Cm
96
Bk
97
Cf
98
Es
99
Fm
100
Md
101
No
102
General Characteristics of Non-metals
Chemistry 120
Bad conductors of electricity
- often insulators or semiconductors
- conductivity rises with increasing
temperature
Bad conductors of heat
Brittle, not maleable, not ductile
15
Chemistry 120
The Non-metals and
s block
p block
1
H
1
2
Li
3
Be
4
He
2
3
Na
11
Mg
12
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
6
Cs
55
Ba
56
Lu
71
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
7
Fr
86
Ra
88
Lr
103
Rf
104
Db
105
Sg
106
Bh
107
Hs
108
Mt
109
The Metals
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
Kr
36
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
Xe
54
Pt
78
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
Rn
86
110
111
112
d block
f block
La
57
Ce
58
Pr
59
Nd
60
Pm
61
Sm
62
Eu
63
Gd
64
Tb
65
Dy
66
Ho
67
Er
68
Tm
69
Yb
70
Ac
89
Th
90
Pa
91
U
92
Np
93
Pu
94
Am
95
Cm
96
Bk
97
Cf
98
Es
99
Fm
100
Md
101
No
102
General Characteristics of Metals
Chemistry 120
Good or excellent conductors of electricity
- conductivity falls with increasing
temperature
- are often superconductors at low
temperature
Good conductors of heat
Often maleable and ductile
- d block metals in general better than
p block metals
Dalton and Compound Atoms
Chemistry 120
John Dalton rejuvenated the
atomic theory and used the
terms compound atoms and
atoms to define the basic
building blocks of matter.
Dalton’s compound atoms are
today’s
MOLECULES
16
Molecules
A molecule is a compound
where two or more atoms
are bound together by
sharing the outer electrons
in a covalent bond.
Chemistry 120
Most molecular species are
formed by the non-metals
Molecules
A molecule is a compound
where two or more atoms
are bound together by
sharing the outer electrons
in a covalent bond.
Chemistry 120
B
5
C
6
N
7
O
8
F
9
Si
14
P
15
S
16
Cl
17
Ge
32
As
33
Se
34
Br
35
Sb
51
Te
52
I
53
Xe
54
Most molecular species are
formed by the non-metals
Elements whose natural
forms occur as molecules
include
Chemistry 120
B
5
C
6
N
7
O
8
F
9
Si
14
P
15
S
16
Cl
17
Ge
32
As
33
Se
34
Br
35
Sb
51
Te
52
I
53
Xe
54
17
include
Nitrogen
Chemistry 120
B
5
N2
C
6
N
7
O
8
F
9
Si
14
P
15
S
16
Cl
17
Ge
32
As
33
Se
34
Br
35
Sb
51
Te
52
I
53
include
Nitrogen
Phosphorous
Chemistry 120
B
5
N2
P4
C
6
N
7
O
8
F
9
Si
14
P
15
S
16
Cl
17
Ge
32
As
33
Se
34
Br
35
Sb
51
Te
52
I
53
include
Nitrogen
Phosphorous
Arsenic
N2
P4
As 4
Xe
54
Xe
54
Chemistry 120
B
5
C
6
N
7
O
8
F
9
Si
14
P
15
S
16
Cl
17
Ge
32
As
33
Se
34
Br
35
Sb
51
Te
52
I
53
Xe
54
18
include
Nitrogen
Phosphorous
Arsenic
Oxygen
Chemistry 120
B
5
N2
P4
As 4
O2
C
6
N
7
O
8
F
9
Si
14
P
15
S
16
Cl
17
Ge
32
As
33
Se
34
Br
35
Sb
51
Te
52
I
53
include
Nitrogen
Phosphorous
Arsenic
Oxygen
Sulfur
Chemistry 120
B
5
N2
P4
As 4
O2
S8
C
6
N
7
O
8
F
9
Si
14
P
15
S
16
Cl
17
Ge
32
As
33
Se
34
Br
35
Sb
51
Te
52
I
53
include
Nitrogen
Phosphorous
Arsenic
Oxygen
Sulfur
N2
P4
As 4
O2
S8
Xe
54
Xe
54
Chemistry 120
B
5
C
6
N
7
O
8
F
9
Si
14
P
15
S
16
Cl
17
Ge
32
As
33
Se
34
Br
35
Sb
51
Te
52
I
53
Fluorine
Xe
54
F2
19
include
Nitrogen
Phosphorous
Arsenic
Oxygen
Sulfur
N2
P4
As 4
O2
S8
Chemistry 120
B
5
C
6
N
7
O
8
F
9
Si
14
P
15
S
16
Cl
17
Ge
32
As
33
Se
34
Br
35
Sb
51
Te
52
I
53
Fluorine
Chlorine
F2
Cl2
include
Nitrogen
Phosphorous
Arsenic
Oxygen
Sulfur
N2
P4
As 4
O2
S8
Chemistry 120
B
5
C
6
N
7
O
8
F
9
Si
14
P
15
S
16
Cl
17
Ge
32
As
33
Se
34
Br
35
Sb
51
Te
52
I
53
Fluorine
Chlorine
Bromine
Nitrogen
Phosphorous
Arsenic
Oxygen
Sulfur
N2
P4
As 4
O2
S8
Xe
54
F2
Cl2
Br2
include
Xe
54
Chemistry 120
B
5
C
6
N
7
O
8
F
9
Si
14
P
15
S
16
Cl
17
Ge
32
As
33
Se
34
Br
35
Sb
51
Te
52
I
53
Fluorine
Chlorine
Bromine
Iodine
Xe
54
F2
Cl2
Br2
I2
20
Chemistry 120
As a molecule is a compound, it has a definite
chemical composition and we write a formula for
the composition:
Elemental sulfur has the formula
S8
Chemistry 120
As a molecule is a compound, it has a definite
chemical composition and we write a formula for
the composition:
Elemental sulfur has the formula
S8
Number of atoms
in the molecule
Chemical Symbol
Methane
CH4
Ethanol
C2H6O
Sulfuric Acid
H2SO4
Chemistry 120
21
Methane
CH4
Ethanol
C2H6O
Sulfuric Acid
H2SO4
Chemistry 120
1 Carbon
4 Hydrogens
2 Carbons
4 Hydrogens
1 Oxygen
2 Hydrogens
1 Sulfur
4 Oxygens
Chemistry 120
There are several types of formulæ (not formulas)
Empirical formula:
The simplest ratio of atoms
Molecular formula: The actual number of atoms
in the molecule
Structural formula:
The structure and number of
atoms in the molecule
Chemistry 120
Empirical formula:
Acetic Acid: CH2O
Glucose
CH2O
Formaldehyde CH2O
22
Empirical formula
Chemistry 120
Molecular
Acetic Acid: CH2O C2H4O2
Glucose
CH2O C6H12O6
Formaldehyde CH2O CH2O
Empirical formula
Chemistry 120
Molecular
Structural
H
H
Acetic Acid: CH2O C2H4O2
Glucose
CH2O C6H12O6
O
C
C
O
H
OHC
H
OH H
OH OH
C C
C C
CH2OH
H HO H H
O
Formaldehyde CH2O CH2O
C
H
H
Chemistry 120
Molecules with the same molecular formula but
different structural formulæ are called
ISOMERS
23
Chemistry 120
ISOMERS
For C2H6O
Chemistry 120
ISOMERS
For C2H6O
H
H
H
C
C
H
H
H
O
Ethanol
Chemistry 120
ISOMERS
For C2H6O
H
H
H
C
C
H
H
H
O
or
Ethanol
24
Chemistry 120
ISOMERS
For C2H6O
H
H
H
C
C
H
H
H
H
O
or
Ethanol
H
C
H
H
O
C
H
H
Dimethyl ether
Chemistry 120
Formulæ tell us
the simplest composition of the molecule
empirical formulæ
Or
the actual composition of the molecule
molecular formulæ
Or
the structure and composition of the molecule
structural formulæ
Chemistry 120
But the three dimensional structure of the molecule
is best represented using models or a chemical
drawing package (e.g. ChemDraw) as the
reactivity and chemistry of a molecule takes place
in three dimensions
25
Chemistry 120
Capsaicin
RDX
Caffeine
Strychnine
http://www.sci.ouc.bc.ca/chem/molecule/molecule.html
Chemistry 120
Writing Formulæ
Prefixes denote the number of atoms
Mono
1
Hexa
6
Di
2
Hepta
7
Tri
3
Octa
8
Tetra
4
Nona
9
Penta
5
Deca
10
Chemistry 120
Writing Formulæ
The first element in the name is the one
farthest to the left
and
lowest in the group
Hydrogen and oxygen are sometimes exceptions
26
Chemistry 120
Writing Formulæ
The second name drops the suffix and adds
-ide
instead
chlorine
chloride
oxygen
oxide
Chemistry 120
Example
1 phosphorous atoms
5 fluorine atoms
Chemistry 120
Example
1 phosphorous atoms
5 fluorine atoms
Phosphorous
27
Chemistry 120
Example
1 phosphorous atoms
5 fluorine atoms
Phosphorous Pentafluor
Chemistry 120
Example
1 phosphorous atoms
5 fluorine atoms
Phosphorous Pentafluoride
PF5
Example
Chemistry 120
S2F10
28
Example
Chemistry 120
S2F10
2 sulfur atoms
- disulfur
Example
Chemistry 120
S2F10
2 sulfur atoms
- disulfur
10 fluorine atoms
- decafluoride
Example
Chemistry 120
S2F10
2 sulfur atoms
- disulfur
10 fluorine atoms
- decafluoride
disulfur decafluoride
29
Chemistry 120
Substances that are made up of molecules tend to
be
mechanically soft
low melting and boiling
electrical insulators in solution and in the
solid state
Chemistry 120
Atoms are neutral
equal numbers of protons (in the nucleus)
and electrons (outside the nucleus)
charge on the electron and proton is equal
An atom that gains or loses one or more
electrons is called an
ION
Chemistry 120
An atom that loses one or more electrons is
positively charged and is called a
CATION
An atom that gains one or more electrons is
negatively charged and is called an
ANION
PROTONS ARE NOT TRANSFERRED FROM
THE NUCLEUS!!!
30
Chemistry 120
Compounds which are made up of ions are called
IONIC
In general they are
hard
brittle
insulators in the solid state but conductors in
solution or in the melt
have high melting points and boiling points
Chemistry 120
Ionic compounds are held together by electrostatic
forces between the ions – they are crystalline and
there is no ‘minimum unit’ analogous to a
molecule
Which element – which ion?
This depends on the electronic structure of
the atom but in the s and p block.......
Monocations
s block
1
Chemistry 120
p block
H
1
He
2
2
Li
3
Be
4
3
Na
11
Mg
12
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
Kr
36
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
6
Cs
55
Ba
56
Lu
71
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
Pt
78
Xe
54
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
Rn
86
d block
Monocations: Li +, Na+, K + , Rb + , Cs +
31
Chemistry 120
Mono- and dications
s block
p block
1
H
1
2
Li
3
Be
4
He
2
3
Na
11
Mg
12
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
6
Cs
55
Ba
56
Lu
71
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
Pt
78
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
Kr
36
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
Xe
54
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
Rn
86
d block
Dications: Be2+, Mg 2+, Ca2+ , Sr 2+, Ba2 +, Sn 2+, Pb 2+
Chemistry 120
Mono-, di- and trications
s block
1
H
1
2
Li
3
Be
4
3
Na
11
Mg
12
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
6
Cs
55
Ba
56
Lu
71
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
Pt
78
p block
He
2
Trications: Al 3+, Ga3+
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
Kr
36
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
Xe
54
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
Rn
86
d block
Dications: Be2+, Mg 2+, Ca2+ , Sr 2+, Ba2 +, Sn 2+, Pb 2+
Chemistry 120
s block
1
p block
H
1
He
2
2
Li
3
Be
4
3
Na
11
Mg
12
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
Kr
36
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
6
Cs
55
Ba
56
Lu
71
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
Pt
78
Xe
54
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
Rn
86
d block
32
1
Chemistry 120
Mono-, di- and trications
H
1
Trications:
Al 3+,
He
2
Ga3+
2
Li
3
Be
4
3
Na
11
Mg
12
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
Kr
36
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
6
Cs
55
Ba
56
Lu
71
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
Pt
78
Xe
54
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
Rn
86
d block
Dications: Be2+, Mg 2+, Ca2+ , Sr 2+, Ba2 +
Sn 2+ , Pb 2+
Trianions N 3-, P 3-
Monoanions
Dianions
O 2-, S2-
Chemistry 120
Transition metals can from ions with more than
one charge. Common ones include
Ti
Ti3+ Ti4+
Co Co 2+ Co 3+
V
V3+
Ni
V4+ V5+
Mn Mn 2+ Mn 4+ Mn 5+
Ni2+
Cu Cu + Cu 2+
Fe2+ Fe3+
Fe
Chemistry 120
1
H
1
2
Li
3
Be
4
He
2
3
Na
11
Mg
12
4
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
5
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
6
Cs
55
Ba
56
Lu
71
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
Pt
78
B
5
C
6
N
7
O
8
F
9
Ne
10
Al
13
Si
14
P
15
S
16
Cl
17
Ar
18
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
Kr
36
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
Xe
54
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
Rn
86
d block
These cations and anions are formed from atoms
but we can form anions and cations from
molecules. These are termed
POLYATOMIC IONS
33
Polyatomic Ions
Chemistry 120
These species exists as anions and cations and
contain several atoms bound together in the same
way as a molecule – covalently – but with one or
more positive or or negative charge.
H
2
O
O
S
O
O
N
O
O
S
O
O
H
C
P
O
O
H
H
H
3
O
H
H
H
H
O
2
O
O
N
H
O
H
C
C
C
C
C
H
S
H
H3 C
C
CH3
CH3
H
Acids, bases and salts
Chemistry 120
Svante Arrhenius defined
an acid is a compound which dissolves
in water or reacts with water to give
hydronium ions, H3O+ (aq)
Svante Arrhenius
(1859 – 1927)
a base is a compound which dissolves
in water or reacts with water to give
hydroxide ions, OH- (aq)
Chemistry 120
Acidic and basic solutions are formed by
dissolution or by reaction.
Dissolution
- a compound containing hydronium
ions, H3O+ (aq)
or hydroxide ions, OH- (aq)
dissociates and gives an acidic or basic solution
Reaction
- a compound reacts with water to form
an acidic or basic solution
34
Chemistry 120
For an acid A, the reaction is
AH + H2 O (l)
A -(aq) + H3 O +(aq)
For a acid B, the reactions are
BOH (s)+ H2O(l)
B + H2 O(l)
+
B
(aq) +
+
BH (aq)
-
OH (aq)
-
+ OH (aq)
Chemistry 120
An example of the formation of an acid solution is
HBr(g) + H 2 O(l)
Br-(aq) + H3 O +(aq)
Chemistry 120
Water is protonated to form the hydronium ion –
hydrogen bromide is a proton donor
HBr(g) + H 2 O(l)
Water
Hydronium
ion
35
Chemistry 120
And the counter ion, necessary for electroneutrality
is bromide ion.
HBr(g) + H 2 O(l)
Hydronium
ion
Bromide
Water
Hydrogen
Bromide
Chemistry 120
An example of the formation of a basic solution by
dissolution is
Na+(aq) + OH- (aq)
NaOH(s)
H2 O(l)
NaOH dissolves in water
to give sodium ions and
hydroxide ions. NaOH is
an ionic solid which
contains hydroxide ions.
Na +
OH-
Chemistry 120
An example of the formation of a basic solution is
NH3(g) + H2 O(l)
+
NH4
(aq) +
-
OH (aq)
Ammonia reacts with water and removes an H+ to
form NH4+ , the ammonium ion,
Basic solutions are formed by reaction or
dissolution – formation of acid solutions by
dissolution are very rare.
36
Chemistry 120
Hydroxide and hydronium ions will react to form
water.
H3O+(aq) + OH-(aq)
2H2 O(l)
The presence of hydroxide and hydronium ions in
water is crucial, though in pure water the
concentration is very low.
Acids and bases also react to form
SALTS
Chemistry 120
Salt formation occurs when an acid and a base
neutralize each other.
H 3O +(aq) + Cl -(aq)
HCl (g) + H 2 O(l)
NaOH(s)
H 2O (l)
Na+(aq) + OH -(aq)
Remember the reaction between hydroxide and
hydronium:
H3O+(aq) + OH-(aq)
2H2 O(l)
Chemistry 120
The acid and base neutralize each other to form
water, leaving Na +(aq) and Cl-(aq) in solution – the
salt
+ H3O+(aq) + Cl-(aq)
Na+(aq) + OH- (aq) +
Na+(aq) + Cl-(aq) + 2H2O(l)
37
Common acids and bases
Chemistry 120
Common acids are
Acid
H2 SO4
Anion(s)
SO4 2-(aq) and HSO 4 -(aq)
Sulfuric acid
X-(aq)
HX
Hydrohalic acids
(X = F, Cl, Br, I)
H3 PO4 Phosphoric acid
H2 CO3
PO4 3-(aq), HPO42-(aq), H2PO4 - (aq)
CO32-(aq) and HCO3 -(aq)
Carbonic acid
Common acids and bases
Chemistry 120
Common Bases are
Base
Anion(s)
MOH
Group IA hydroxides
(M = Li, Na, K, Rb, Cs)
M (aq)+ , OH(aq) -
M(OH)2 Group IIA hydroxides
(M = Mg, Ca, Sr, Ba)
M (aq)2+, OH(aq)-
NH3, RNH2, R2NH, R3N
NH4+ , RNH3+
OH(aq)R2NH2+ R3NH+
Introduction to Organic Chemistry
Chemistry 120
- Hydrocarbons
- Alkanes
- Alkenes
- Alkynes
- Functional groups
- Alcohols
- Ethers
- Carboxylic Acids
- Esters
38
Organic Chemistry is the study of
compounds composed of carbon, with
H, O, N, P, S and X (X = F, Cl, Br, I).
The name stems from the isolation of
these compounds initially from living
bodies – plants and animals.
Chemistry 120
C
6
N
7
O
8
F
9
Si
14
P
15
S
16
Cl
17
Br
35
I
53
In
1828,
Friedrich
Wohler
synthesized urea from ammonium Friedrich Wohler
cyanate, organic from inorganic. O (1800-1882)
[NH4+][NCO-]
Ammonium Cyanate
C
H2 N
Urea
Hydrocarbons
NH2
Chemistry 120
Hydrocarbons are the basic compounds of organic
chemistry and are simply compounds of carbon and
hydrogen.
There are three types
Alkanes
Alkenes
Alkynes
Alkanes are termed saturated hydrocarbons,
whereas alkenes and alkynes are unsaturated.
Chemistry 120
Carbon contains four electrons in the outer shell and
1
H
1
2
Li
3
He
2
Be
4
B
5
C
6
N
7
O
8
F
9
Ne
10
can share all four with other atoms or itself.
We say that the valence of carbon is four and so the
simplest hydrocarbon is CH4, methane. We draw
methane as
H
H
C
H C
H
H
H
H
H
H
H
H
C
H
39
Chemistry 120
The next saturated hydrocarbon or alkane is ethane,
C2H6, which has the structure
H
H
C
C
H
H
H
H
H
H
H
H
H
H
C
C
C
H
H
C
H
H
Followed by propane
H
C
H
H H
H
H
C
H
C
C
H
H
H
H
H
Chemistry 120
Important hydrocarbon fragments (which are not
molecules)
Methane
Methyl
MeH
H
C
H
CH3-
H
H
C
H
Methane
Chemistry 120
Methyl
Me-
CH3H
H
Methyl Iodide Me-I
H
H
C
I
H
C
I
H
40
Methane
Chemistry 120
Methyl
Me-
CH3H
H
Methyl Iodide Me-I
C
H
I
H
C
H
Methane
Chemistry 120
Methyl
Me-
Methyl Alcohol
CH3H
H
Methanol Me-OH
C
H
OH
H
H
OH
Chemistry 120
Methyl
Me-
Methyl Alcohol
Methanol Me-OH
C
H
Methane
I
H
CH3H
H
H
H
C
OH
H
C
OH
H
41
Chemistry 120
Other important hydrocarbon fragments (which are
not molecules)
Ethane
Ethyl
EtC2H5H
H
C
C
H
H
H H
H
H
C
C
H
H
Propane
Propyl
Pr-
C3H7-
Butane
Butyl
Bu-
C4H9-
Chemistry 120
Isomers in organic chemistry
Every carbon atom has four bonds. With methane,
ethane and propane, there is only one way of
forming the hydrocarbon.
The structural formula is identical to the molecular
formula and there is only one way of writing the
structural formula, consistent with the molecular
formula.
Every carbon atom
H
has four bonds. With H C
methane, ethane and
H
propane, there is only
H
one way of arranging H C
the atoms.
H
H
H
C
H
Chemistry 120
H
C
H
H
H
C
H
H
C
H
H
H
H
H
H
H
C
H
H
H
C
H
H
C
H
C
H
H
H
H
C
C
H
H
H H
There is only one structural formula for each
molecular formula
42
Butane, C4H10, can have
more than one structural
formula for the molecular
formula
Chemistry 120
H
H
H
H
H
H
C
C
C
C
H
H
H
H
H
H
H
C
C
C
C
H
H
H
H
H
H
H
There is more than one structural formula for each
molecular formula
Butane, C4H10, can
have more than one
structural formula for
the molecular formula
Chemistry 120
H
There is more than one
structural formula for each
molecular formula.
H
H
H
H
C
C
C
C
H
H
H
H
H
THEY ARE ISOMERIC
H
H
H
C
C
C
H
H
C
H
H
H
H
H
Isomers in organic chemistry
Chemistry 120
Pentane has more isomers.......
H
H
H
H
C
H
H
H
C
H H
C
H
C
H
H
H
C
H
H
C
H
H
C
H
C
H
H
C
H
H
C
H
H
H
H
C
H
C
H
C
H
C
H
C
H
H
H
H
H
H
43
Chemistry 120
In CnH2n+2, the linear alkanes , the number of
isomers rises rapidly with n, the number of carbon
CnH 2n+2
n
Number of Isomers
atoms
Butane
4
2
Pentane
Hexane
5
6
3
5
Heptane
Octane
7
8
9
18
Nonane
Decane
9
10
35
75
Dodecane
Pentadecane
12
15
355
4,347
Icosane
20
366,319
The C-C chain in an
alkane may also be
joined end to end to
form a ring, the cyclic
alkanes.
Whereas
linear alkanes have a
formula CnH2n+2, the
cyclic alkanes have a
formula CnH2n.
Chemistry 120
H2C
CH2
H2C
H2C
H2C
CH2
CH2
CH2
H2C
H2C
CH2
CH2
CH2
H2C
CH2
H2C
CH2
CH2
Alkenes and Alkynes
Chemistry 120
In the alkane series, only one electron per carbon is
shared between carbon atoms. This is termed a
single bond and contains an electron pair, 1 e- from
each C atom.
H
H
H
Ethane H
H
H
C
H
H
C
C
H
H
H
C
H
Here red denotes electrons from C and green denotes
electrons from H.
44
Alkenes and Alkynes
Chemistry 120
In an alkene or alkyne, a C atom shares two
electrons with a neighboring atom to form a double
bond or triple bond containing 4 or 6 electrons.
H
Ethene
C
(Ethylene)
Ethyne
H
H
H
H
C
C
H
C
H
H
C
H
H
C
H
C
H
C
(Acetylene)
Functional groups
Chemistry 120
We can expand the number of compounds possible
by binding different functional groups to a
hydrocarbon fragment such as methyl or ethyl.
Alcohols
-OH
Amines
-NH2
Alkyl halides
-X
Functional groups
Chemistry 120
Methane Methanol Methylamine Chloro methane
H
H
C
H
H
H
C OH
C
H
H
H
C
Cl
C
H
H
OH
H
C
Cl
H
H
H
H
H
H
H
H
H
H
H
C
H
H
Cl
H
C
Cl
H
45
Functional groups
Chemistry 120
Replacing a –CH2– group in an alkane gives an
ether
Pentane
Diethyl ether
CH2
H3C
H
CH2
CH2
H
H
H
H
H
C
C
C
C
C
H
H
H
H
H
CH2
CH3
H3C
H
H
CH2
O
H
H
C
C
H
H
CH3
O
More complex functional groups
H
H
C
C
H
H
H
Chemistry 120
Introducing a double bond to oxygen gives a whole
series of new classes of compounds
Ketones
Pentane
3-pentanone
2-pentanone
O
CH2
H3C
H
CH2
CH2
H
H H
C
C
H
H H
H
H
C C
C
H
H 3C
CH3
H
H
H3 C
C
H
5
4
H
H
C
C
H
H
CH2
CH3
CH 2
CH 2
CH3
C
CH 2
3
O
C
2
1
H
H
C
C
H
H
5
H
H
4
O
2
3
1
H
H
H
O
H
C
C
C
C
C
H
H
H
Aldehydes
H
H
Chemistry 120
If the C=O function is at the end of the chain, then
the compound is termed an aldehyde
Pentane
Pentanal
CH2
H 3C
O
CH2
CH2
CH3
H3C
CH2
CH2
H
H
H H
H
H
C
C
C
C
C
H
H H
H
H
H
H
C
CH2
H
H
H
H
C
C
C
C
H
H
H
H
H
O
C
H
46
Carboxylic acids, esters and amides
Chemistry 120
These classes of molecules contain the group
O
C
Z
Z = -OH, -OR, NR 2, -X
Carboxylic acids, esters and amides
Chemistry 120
Z varies according to
O
O
C
C
OH
O
Carboxylic ac id
OR
Carboxylic Ester
C
NR2
O
Carboxylic Amide
X
Carboxylic Acid Halide
C
47

Chemical Composition of the World: Atoms 101 ???? “indivisible

Transcription

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