Transcript Organic Chemistry

What is Organic
Chemistry?
Theobromine- found in chocolate
Essential Questions: What is organic chemistry? What
are some unique characteristics of carbon?
Organic Chemistry:
1. Study of carbon and compounds containing
carbon
2. Number of organic compounds is much more
that the number of inorganic compounds (does
not contain C). 10,000 new ones discovered
each year.
Hydrocarbon-organic compounds that contain
only atoms of carbon and hydrogen, Exs:
alkanes, alkenes, alkynes
What is a hydrocarbon?

Hydrocarbons are
made up just of
carbon and hydrogen.
 Methane, CH4, is the
simplest.
CARBON is the center of Organic
Chemistry
•This is C12.
•6 protons
•6 neutrons
•6 electrons
•4 valence
electrons
•Always
makes 4
bonds.
Carbon- infinite bonding
possibilities:
Carbon
frequently
bonds with
hydrogen
(yellow)
and/or with
oxygen (red).
Diamonds are pure carbon.





The carbons are joined
just to other carbons.
Each C joined to 4
others.
Very strongly bonded.
Example of a
NETWORK SOLID.
High m.p.,
nonconductor
Bonding of carbon atoms:
 Has 4 valence electrons
 Forms 4 covalent bonds
 Can form a single, double, or triple covalent
bond.
 Each carbon atom is in the center of
tetrahedron.
Single Covalent Bond-shares 1 pair of electrons
Double Covalent bond-shares 2 pair of electrons
Triple Covalent Bond- shares 3 pair of electrons
Organic compounds have
the following properties:
 Low
melting point
 Low solubility in water (they are nonpolar)
 Nonelectrolytes
 Covalent bonds
 Slower reaction rates
 Weak intermolecular forces
Saturated –organic compounds with only
single covalent bonds.
Unsaturated Compounds – compounds
that contain double or triple covalent
bonds.
Basic hydrocarbons:

The first four have all
single bonds
 All single bonds 
SATURATED
 Saturated  end in ane

Containing a multiple
bond  Unsaturated.
Essential Questions: What are the types of
hydrocarbons? What are the characteristics of
each type?
Types of hydrocarbons
 Alkanes
 Alkenes
 Alkynes
All are classified as a homologous series *
Homologous series -is a group of related
compounds in which each member differs
from the one before it by the same
additional unit.
1. Alkanes:
 Nonpolar molecules
 Low molar mass
 Have weak Van der Waals Forces
 Tend to be gases or liquids that have a low BP
 Hydrocarbon in which there is only single
covalent bonds
 Tends to release energy when burned
 When the number of carbon increase in the
series, the B.P increases
 General formula is: Cn H 2n+2
 End is ane.
Exs. pentane and hexane
 Table Q
Methane (CH4)- make up 90% of natural gas
Ethane (C2H2)- accounts for the rest of natural gas
Propane (C3H6)- used for home heating fuel, grills,
camping equipment
Butane (C4H10)- used in disposable lighters
Other membranes of the alkanes:
 Pentane C5H12
 Hexane C6H14
 Heptane C7H16
 Octane C8H15
 Nonane C9H20
 Decane C10H22
 Prefix is based on number of carbons
 Table P
Single bonded
hydrocarbons…

Saturated
 Called ALKANES
 Have general formula:
CnH2n+2

Since same formula,
they are part of a
homologous series
 Table Q
Alkene:
•
•
•
Unsaturated hydrocarbons
Contain double covalent bonds
End in ene
Ex: ethene, propene
 .General Formula: Cn H2n
Sometimes we have
double bonds…

Series is called
alkenes
 General formula:
CnH2n

Unsaturated (contain
a multiple bond)
First Three Members of the alkenes:
 Ethene
C2H4
 Propene C3H6
 Butene C4H8
Alkynes:
 Unsaturated hydrocarbons
 Contains triple covalent bond
 End in yne
Ex: propyne, butyne
 General formula :Cn H2n-2
Ethyne
 Also known as acetylene
 Fuel use in welding torches
Sometimes we have a
triple bond…
Alkynes
formula: CnH2n-2
 Unsaturated
 General
 Hydrocarbons
can be straight chained,
branched or cyclical
Straight Chain
Ex: Butane
 Branched 2-methyl propane
 Cyclical Ex: benzene
Essential Questions: What are isomers? What are the
characteristics of isomers?
Isomers:
1. Compound that have same molecular
formula, but different structure.
2. Have different physical and chemical
properties
3. As the numbers of carbons in a
compound increase, so does the number
of possible isomers
What are isomers?
Same atoms, different
structure:
Butane
methyl propane
C4H10
1-hexene
cyclohexene
C6H12
Let’s try more…
Both are
butene- how
can I
distinguish
them?
Same formula but
different structuresthese are
ISOMERS!!
How to name
hydrocarbons:

Identify the longest
carbon chain
 Identify whether
hydrocarbon is alkane
(single bonded),
alkene (double), or
alkyne (triple).
 Name will be root plus
suffix.
3 carbon chain propSingle bonds - ane
PROPANE
Sometimes we have
branched hydrocarbons…

One carbon branch (CH3-) = methyl
 Two carbon branch (CH3CH2-) = ethyl
2-methyl
pentane
3-methyl
pentane
Sometimes we have
multiple branches…

2,2-dimethyl-3ethylpentane

2,2-dimethyl pentane

Use di-,tri-, … for
identical branches.
Cyclic Hydrocarbons-A hydrocarbon chain that is
formed in a ring.
Aromatic Hydrocarbon:
1. An organic compound that contains a benzene
ring (C6H6) or other ring in which the bonding is
like benzene.
2. Class of compounds responsible for aromas of
spices. Exs: ginger, cloves, vanilla, etc.
Benzene
In benzene, the bonding electrons between carbon
atoms are shared evenly around the ring.
Toluene- a compound with a benzene ring with an
attached methyl group
Sometimes the carbons link
up to form rings:

Cyclopentane
 All single bonds

Cyclohexane
 All single bonds
More rings !!

benzene
Phenol
(benzene
ring
abbreviated)
toluene
Essential Question: What is distillation?
Fractional Distallation:
1. Process used to separate components of
crude oil. Exs. Kerosene, fuel oil, gas, etc.
2. Based on differences in BP
3. Column is hotter are the bottom, thus the
substance with the highest BP condenses
near the bottom.
Essential Questions: What are functional
groups? What are the formulas for each
group?
Functional Groups:
 Halides (Hydrocarbons)
 Alcohols
 Aldehydes
 Ketones
 Ethers
 Organic Compounds
 Esters
 Amines
 Amino Acids
 Amides
Alcohols:
a. Organic compounds in which one or
more hydrogen atoms of a hydrocarbon
are replaced by an OH- group(hydroxyl
group).
b. OH (hydroxyl group) gives alcohols their
specific chemical and physical properties.
c. Are non-electrolytes-do not ionize in
water.
d. Do not turn indicators colors.
e. Are polar molecules, thus soluble in water
Alcohols:
Alcohols contain –
OH, a functional
group.
 The functional groups
gives them away.
 See table R for
functional groups

Ethanol ↓, methanol ↑
Primary:
a. Represented by:
ROH or R-CH2-OH
b. Alcohols can also be classified by the
number of hydroxyl groups that are
attached to the carbon chain.
 Monohyroxy – 1 hydroxyl group
 Dihydroxy – 2 hydroxyl groups
 Tridhydroxly-3 hydroxyl groups
Essential Question: What is the difference
between primary, secondary and tertiary
alcohol?
Types of Alcohols:
1. Primary
2. Secondary
3. Tertiary
 Classified according to the carbon at
which the OH group is attached.
 Alcohols end in ol.
Name that alcohol…

2-butanol

ethanol
Halides(Hydrocarbons):
a. Occurs when any halogen (F,Cl, Br or I)
replaces a hydrogen atom in an alkane
b. Often used as organic solvents
c. Found in some pesticides.
3. Aldehydes:
1. When an oxygen atom is attached to a
carbon chain by a double covalent bond
called a carbonyl group(-C=0).
•
•
General formula is RCHO
Named by substituting al in place of the final e
of the corresponding alkane name
Aldehydes
Ethanal

2 carbons = eth-

CHO functional group
= al ending.
Ketone- an organic compound in which the
carbon of the carbonyl group (C=O) is
joined by 2 other carbons
•
•
•
General formula – RCOR
Naming by replacing final e from the
corresponding alkane name with one
Used as a solvent, very polar substance
Ketone – hydrocarbons
connected by C=O

Propanone (acetone)
Another aldehyde and
ketone…
Aldehyde and Ketone
Ethers:
a. Series of organic compounds in which
two carbons chains are joined by an
oxygen atom bonded between two
carbon atoms
b. General formula:
An ALCOHOL and an
ETHER
ETHERS- hydrocarbons
connected with an oxygen

Dimethyl ether

Diethyl ether

Methyl ethyl ether
Organic Acids:
1. A homologous series of organic
compound whose functional group
(COOH), a carboxyl group
2. Named by replacing the e on the
hydrocarbon name with oic acid
Exs:
Ethanoic acid(vinegar)CH3COOH
Propanoic acid CH3CH2C00H
Organic acid- COOH on
end of hydrocarbon.

Ethanoic acid (acetic
acid)

Propanoic acid
Esters:
1.General formula R-CO-OR (The R-COOH
comes from an organic acid and the R
comes from an alcohol)
2. Have strong fragrant aromas and are
responsible for the odors of many foods
and flavoring. Ex: wintergreen, pineapple
3.Named by using the alkyl name of the
alcohol followed by the acid group
modified to end in oate
Exs: Methyl Ethanoate and Ethyl Ethanoate
Ester – Oxygen in the
chain and off the chain.
•Ethyl propanoate
•Name is short chain plus
long chain plus “oate”.
Amines:
1. When one or more hydrogens atoms of
ammonia (NH3) are replaced by an alkyl
group
2. The e ending of an alkane is changed to
end in amine and the alkane chain is
numbered to show the location of the
amine group
Amine- N in the chain.
 Pentanamine
 Name
is Prefix + amine
 No number required
Amide – N in the chain
and O off the chain.
Name is “hydrocarbon
root + amide”
 Ethanamide 


Butanamide 
Amino Acids:
1.Contains a carboxyl group (COOH) and a amine
group
2.Amino group is attached to the C atom that is
adjacent to the acid group
Ex: alanine
3.Ten essential A.A that the body must obtain
through diet
4.Building blocks of proteins
Amides- formed when one hydrogen atom of the
amino group reacts with the OH- of the organic
acid
Essential Questions: What are the different type
of organic reactions? What is the chemical
reaction of each type?
 Types
of Organic Reactions:
 1. Combustion
 2. Substitution
 3. Addition
 4. Esterification
 5. Saponification
 6. Fermentation
 7. Polymerization
Combustion- most common type of organic
reaction
•
•
Complete combustion – carbon dioxide is
produced
Incomplete combustion – carbon
monoxide is produced
Substitution- Replacement of one or more
H atoms in a saturated hydrocarbon with
another group or atom
Addition:
a. Adding one ore more atoms at a double or
triple bond
b. Unsaturated hydrocarbon can also react
with hydrogen by addition reactions
Etherification:
a. A reaction
between an
organic acid and
an alcohol
b. Produces an
ester and water
Sponification – one
ester reacts with an
inorganic base to
produce an alcohol
and a soap
Fermentation- process
in which yeast cells
secrete the enzyme
zymase to break
down glucose
Fermentation
Polymerization- process by which a
polymer is made
Ex: plastics, rayon, nylon, polyethylene,
proteins, starches
Polymer- chain of repeating units of
monomers
Two Types of Polymerization:
1.
Addition Polymerization
2.
Condensation Polymerization
Addition Polymerization:
a.
Involving the joining of monomers of unsaturated
compounds.
b.
General formula: nC2H2(C2H2)n
Condensation Polymerization – Results from the bonding
of monomers by removal of water from the hydroxyl
groups and joining the monomers by an ether or ester
linkage (Dehydration synthesis).