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Chemistry 20
Chapter 1
Organic Chemistry
Organic Compounds
Organic Compounds
Chemistry of Carbon (H, O, N, S, Halogens, and P).
H: 0.9%
Ti: 0.6%
Others: 0.9%
C one of the 116 elements
Organic Compounds
Isolation from nature (animal and plant)
(extract-isolate-purify)
Obtained by:
Synthesis in lab
Organic compounds: 10 million
Inorganic compound: 1.7 million
Compounds in living systems are organic: Biochemistry
Organic Compounds
First organic compound that is synthesized in lab.
Wöhler (1828)
NH4 Cl + AgNCO
A mmonium Silver
ch loride
cyan ate
heat
O
H2 N-C-NH2 + AgCl
U rea
Silver
chloride
Organic Compounds
Typical organic compounds:
• Contain carbon
• Have covalent bonds
• Have low melting points
• Have low boiling points
• Are flammable (all burn)
• Are soluble in nonpolar solvents
• May be gases, liquids or solids
C3H8
Propane
Organic Compounds
Organi c Comp ound s
Ino rg an ic Co mpou nds
Bond ing is almost entirel y co val ent
May be g ases, li quid s, o r so li ds
w ith l ow melti ng po ints (l ess
than 360°C)
Mo st are i nsol ubl e in w ater
Mo st are so lu ble i n o rg an ic so lv en ts
such as d iethy l ether, to luene, and
dichl orometh ane
Aqu eo us so lutio ns do n ot
condu ct el ectrici ty
Al most all burn
M ost have i oni c bo nds
M ost are sol id s w ith h ig h
melting po in ts
Reacti ons are usuall y sl ow
Reactio ns are o ften very fast
M any are so lu ble i n w ater
A lmo st al l are i nso lubl e in
o rgani c so lvents
A queous sol uti ons cond uct
electrici ty
V ery f ew burn
Structural Formula (Lewis Structure)
shows the atoms present in a molecule as well as
the bonds that connect them.
HH
HH
H
C C
H-C C-H
H
H
Eth ylen e
(bond angles
120°)
Acetylene
(bond an gles
180°)
H-C-C-Cl :
HH
Ch loroeth ane
(bond angles
109.5°)
H
:
:
: :
: :
H
H
H
H-C-N-H
H-C-O-H
C O
H
H
HH
Methanol Formald ehyde Methan amin e
(b ond angles (bond angles
(bond angles
109.5°)
120°)
109.5°)
: :
H-C-C-H
HH
Eth ane
(bond angles
109.5°)
H
C N
H
H
Methyleneimine
(bond angles 120°)
VSEPR Model
VSEPR: Valence-Shell Electron-Pair Repulsion method
Bond angle: angle between two atoms bonded to a central atom.
Each region of electron likes to be
as far away as possible from the others.
Regions of electron density
Four regions of electron density around an atom:
Bond Angles & Geometric Structures
Linear molecules
2 regions
Trigonal planar
molecules
3 regions
Tetrahedral arrangement
4 regions
Tetrahedral Electron Pair Geometry
(Tetrahedral arrangement)
Tetrahedral Electron Pair Geometry
Unshared electron paires
CH4
NH3
H2O
– Carbon: normally forms four covalent bonds and has no unshared pairs
of electrons.
C
– Hydrogen: forms one covalent bond and no unshared pairs of electrons.
H
– Nitrogen: normally forms three covalent bonds and has one unshared
pair of electrons.
N
..
– Oxygen: normally forms two covalent bonds and has two unshared
pairs of electrons.
..
.O
. =
– A Halogen: normally forms one covalent bond and has three unshared
..
pairs of electrons.
..Cl
..
Functional groups
An atom or group of atoms within a molecule that shows a
characteristic set of predictable physical and chemical
properties.
– A way to classify organic compounds into families.
– They determine the chemical and physical properties of a compound.
– They undergo the same types of chemical reactions.
– A way to name organic compounds.
Functional groups
Family
Functional
group
Example
Name
Alcohol
- OH
CH3 CH2 OH
Ethanol
Amine
CH3 CH2 NH 2
O
CH3 CH
O
CH3 CCH3
O
CH3 COH
Ethanamine
Carboxylic acid
- NH2
O
- C- H
O
- CO
- C- OH
Carboxylic ester
O
- C- OR
O
CH3 COCH 2 CH 3
Aldehyde
Ketone
Ethanal
Acetone
Acetic acid
Ethyl acetate
Alkanes, Alkenes, and Alkynes
• Alkanes: contain single
bonds between carbon
atoms.
C
• Alkenes: contain one or
more double bonds.
C
C
C
C
• Alkynes: contain one or
more triple bonds.
C
Alcohols and Ethers
O
• Alcohols: contain the
hydroxyl (-OH) functional
group.
• Ethers: an oxygen atom is
bonded to two carbon atoms.
O
C
C
O C
C
C
C
H
Functional
Aldehydes and Ketones
Family
Example
group
Alcohol
• Aldehydes: contain a
Amine
carbonyl
group
(C=O),Family
which is a
carbonAlcohol
atom
with a
Aldehyde
double bond to an
Amine
oxygen
atom.
Ketone
- OH
- NH2
Functional
group
O
C- H
--OH
O
- NH
2
- CO
O
• Ketones:
the
carbon
Aldehyde
- C- H
Carboxylic acid - C- OH
of the carbonyl
O
group is attached to
O
Ketone
two other
carbon ester --CCarboxylic
C- OR
atoms.
O
Carboxylic acid
- C- OH
O
Na
Et
CH3 CH2 OH
O
CH3 CH2 NH 2
C
C
Example
O
H
CH
CH
CH33 CH2 OH
CH3OCH2 NH 2
CH3 CCH3
O
OO
CH3 CH
CH3 COH
C
Et
Et
Ac
Ac
O
CO
C
CH CCH
CH33COCH32 CH 3 Et
O
CH3 COH
O
Alcohol
- OH
CH3 CH2 OH
CarboxylicFunctional
acids and Esters
Amine
- NH2
CH3 CH2 NH 2
Family
Example
group
O
O
• Carboxylic
Alcohol acids: contain
O 2 OH
OH
CH
CH
3
Aldehyde
C- H
CH3 CH
the
carboxyl group -(-COOH),
Amine
CH
C 2 NH
H 2
which
is a carbonyl group
O- NH2
O3 CH
O
attached to a hydroxyl O
O
Ketone
- CCH3 CCH3
group.
Aldehyde
CH
O- C- H
O3 CH
O
Carboxylic acid - C- O
OH
CH3 COH
Ketone
CH
O- CO3OCCH3
O
O CH
Carboxylic
ester
COR
CH
COCH
3 C
2C
3
• Esters: the hydroxyl group
acidis - C- OH
CH3 COH
O
of aCarboxylic
carboxylic acid
Etha
Etha
Etha
Ace
Ace
Ethy
C
replaced by a carbon
atom.
Carboxylic ester
O
- C- OR
O
CH3 COCH 2 CH 3
Amines and Amides
• Amines: the functional
Functional
group is a nitrogen
Family
group
atom.
C
Alcohol |
- OH
Amine— N —
- NH2
O
Aldehyde
- C- H
• Amides: the hydroxyl
group of a carboxylicO
acid is replaced by -aCKetone
nitrogen group.
O
Carboxylic acid - C- NR
OH
Example
Nam
N
N
CH3 CH2COH
CH3 CH2 NH 2
O
CH3 CH
O
O
C
CH3 CCH
3
N
O
CH3 COH
C
Etha
Etha
Etha
Ace
Ace