Transcript Organic_Chemistry - TangHua2012-2013

Unit X
Organic Chemistry
Shelly Wei
Mathew Jiang
Johnny Yu
Mike Chi
A prior question:
What is ORGANIC CHEMISTRY?
Organic Chemistry: It is a
chemistry sub-discipline involving
the scientific study of the structure,
properties, and reactions of organic
compounds and organic materials,
i.e. matter in its various forms that
contain…
Carbon Atoms!
*Review Questions*
What is functional groups?
 Functional Groups: A Functional group
is a specific group of atoms which exists in a
molecule and gives a molecule an ability to
react in a specific manner or gives it specific
properties.
 Different groups of atoms have different manner
or properties.
Any Examples of functional groups?
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Halides
Carbon-carbon double bonds (in alkenes)
Carbon-carbon triple bonds (in alkynes)
Alcohol
Aldehydes
Ketones
….
Now…
• There is something that can also be
categorized into functional groups, and it is
called…
Ether!
Organic Chemistry Lesson
Carboxylic Acids
Mathew Jiang
Mike Chi
What kind of substance would you
judge only after your smelling?
• Yes, it is…
Vinegar!
What is carboxylic acid?
“Organic Acids”
• Carboxylic Acid: It is an organic compound
which contains a COOH group. The COOH
group is also sometimes shown as…
What is R?
R is a monovalent
functional group.
Something
that possesses
a charge of -1.
How to name it?
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Let me show you some examples…
CH3COOH
• Ethanoic acid
HCOOH
• Methanoic acid
CH3-CH2-CH2-COOH • Butanoic acid
Why?
Find the regulation?
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How many carbons are there in carboxylic acid?
The number of carbons  Prefixes
Prefix + oic + Acid
 That is how the name comes from!
Practice Problems
• Pg.240 #37
 Just identify which are the carboxylic acids?
Properties of Ether
What is an ether??
• A compound in which an oxygen joins two
hydrocarbon groups
• Several ethers have anaesthetic properties:
ethoxyethane was formerly used in hospitals
and is still used by biologists to “quiet” or
anaesthetize insects
Physical Properties-4 kinds
• Physical state: Methoxy methane and methoxy ethane are
gases while other members are volatile liquid with pleasant
smell.
• Dipole moment: Bond angle of ether is due
to hybridisation of oxygen atom. Since C – O bond is a
polar bond, hence ether possess a net dipole moment,
even if they are symmetrical. dipole moment of dimethyl
ether is 1.3 D and dipole moment of di ethyl ether is 1.18 D.
• Boiling points: Boiling points of ethers are much lower
than those of isomeric alcohols, but closer to alkanes
having comparable mass. This is due to the absence of
hydrogen bonding in ethers.
• Solubility: Solubilities of ethers in water are comparable
with those of alcohols.
Examples
• Di ethyl ether and n-butyl alcohol have
approximately the same solubility in water. This is
because, ether form hydrogen bond with water
much in the same way as alcohol do with water.
• Solubility of ether in water decreases with the
size of alkyl groups.
Exercises
• Which of the following are isomers?
(a) Methyl alcohol and dimethyl ether
(b) Ethyl alcohol and dimethyl ether
(c) Acetone and acetaldehyde
(d) Propionic acid and propanone
Answer: B
Exercises
• Oxygen atom in ether is?
(a) Very active
(b) Replaceable
(c) Comparatively inert
(d) Active
Answer: C
Thanks for your attention!