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ORGANIC

CHEMISTRY

NAME:

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Learning Goals:

Explain the difference between organic and inorganic compounds.

Identify where organic molecules are sourced from.

Understand how carbon, hydrogen, nitrogen, oxygen, and halogens

bond to form organic molecules.

Identify, draw, and name alkanes, alkenes, and alkynes.

Draw and name hydrocarbons with halogens.

Draw and name branched isomers.

Draw and name branched alkanes, alkenes, and alkynes.

Draw molecules using structural, condensed, and skeletal strategies.

Identify saturated and unsaturated carbon chains.

Explain how the process which separates petroleum works.

Compare, name and draw cyclic aliphatic and aromatic compounds.

Draw and explain the special features of benzene.

Explain what a functional group is and identify, draw, and name

alcohols, carboxylic acids, and esters.

Identify uses of organic functional groups and aromatic compounds.

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The Beginning: What is Organic Chemistry?

Organic chemistry is the study of containing

molecules. The molecules may contain other elements as well, namely

hydrogen, , , sulfur, phosphorus,

and any halogen. These molecules come from decay of prehistoric

animals and , and are typically known to us as

fossil fuels.

Examples of Organic Molecules are…

Non-examples of Organic Molecules are…

Covalent bonding is very important in organic chemistry so we are going

to review bonding of the main elements in organic chemistry.

C N O F

Valence electrons

Remember that in covalently bonded compounds, you may have

than one bond, for example in carbon monoxide. Carbon brings

valence electrons, oxygen brings valence electrons. Together

they have available electrons for bonding. To satisfy the octet

rule and give each atom electrons, they have to share 6 electrons.

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Carbon-Carbon bonds: Alkanes, Alkenes, and Alkynes

There are 3 different types of bonds that molecules use to connect to

each other: , , and .

In organic chemistry we have special names for molecules for the 3

different types of bonds when they are between 2

atoms with atoms attached to fill carbon’s bonds.

1) A single bond (C-C) is called an . These are very

weak bonds that break easily, so these molecules are often found

in the phase and melt or boil at low temperatures.

Example:

2) A double bond (C=C) is called an . These are

medium strength bonds and are found in a variety of phases.

Example:

3) A triple bond (C=C) is called an . These are very

strong bonds and are also found in a variety of phases.

Example:

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Having an alkane, alkene, or alkyne however does not just mean two

carbon atoms linked together. We can have many carbon atoms linked

in a row surrounded by hydrogen atoms.

Ex: Draw 3 carbons linked together by single bonds with all hydrogens.

We can draw molecules in 3 different forms.

a) Expanded form: Draw all atoms connected by line bonds.

b) Condensed form: Write each carbon with hydrogens connected by

line bonds.

c) Skeletal form: To be discussed later on.

Naming Part 1: Alkanes, Alkenes, Alkynes

An organic molecule is named according to the bond that

it has. If a molecule has 3 single bonds and 1 double bond, it would be

called an . Label each molecule as an alkane, alkene

or alkyne.

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The second step to naming these molecules is to count the longest

chain of atoms in the molecule which is called the

chain. This chain is not always a straight line, it can

have corners and bends. We then use a system of prefixes depending

on the number of carbons.

Prefix:

1 6

2 7

3 8

4 9

5 10

After finding the prefix, we use a suffix based on whether the

molecule is an alkane, alkene, or alkyne. Alkanes will end in ,

alkenes will end in , and alkynes will end in .

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Expanded Condensed IUPAC Name

CH4

C2H6

CH3-CH3

Ethane

C3H8

C4H10

C5H12

C6H14

Expanded Condensed IUPAC Name

C2H4

CH2=CH2

C2H2

Ethyne

As you can see in these charts above, adding double or triple bonds

the number of hydrogens needed.

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General Formulas

Rather than drawing to find out how many hydrogens are needed for a

particular number of straight chain carbons, formulas have been made.

Alkanes: Alkane with 12C:

Alkenes: Alkene with 6C:

Alkynes: Alkyne with 9C:

Practice: Name the following by using the general formulas.

C2H2

C5H12

C3H8

C4H6

C2H4

C7H14

C7H16

C6H10

Branching and Isomers

What happens if our molecules have off of our

straight carbon chain? These are called . To

communicate to other people whether our molecule is in a straight line

or branched we need a few more naming rules.

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Naming Part 2: Branches

To name a branch coming off of a carbon chain, use the following steps:

1) Is it a halogen? Use the following names:

F: Fluoro

I: Iodo

Br: Bromo

Cl: Chloro

2) Is it a carbon-hydrogen group? Use the IUPAC prefixes you

already know, ended by –yl:

CH3 : methyl

CH2 – CH3 : ethyl

CH2 - CH2 – CH3 : propyl

3) What carbon number is your branch coming off of? This number

goes in front of its name.

To name a branched molecule, use the following steps:

1) Find and name the longest continuous carbon chain (parent chain).

2) Number the carbons in the chain starting at which ever end is

closest to a branched add on.

3) Name your branches using the above rules.

4) Do you have more than one of the same type of branch? Use the

same prefixes as for covalent naming to indicate how many of

that type of branch there are on the molecule.

2 – di 3 – tri 4 - tetra ex) dimethyl means 2 methyls

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5) Put the substituent groups in alphabetical order NOT considering

any prefixes (ex. Diethyl would be alphabetized by e not d) and

use hyphens in between numbers and names with the parent

carbon chain name coming last.

2-chloro-3-methylbutane 4-bromo-2-methylhexane

Example: Name the following molecules.

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Example: Draw the following molecules.

3,3-diethyl-pentane

3-methyl-hexane

2-methyl-2-iodo-butane

You may notice that some molecules have the same formula (number of

carbons and hydrogens) but are arranged in a different shape. These

molecules would be called . Isomers all have

properties which make them unique molecules.

Draw an isomer of butane:

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Draw an isomer of hexane:

Naming Part 3: Multiple Bonds

If we are naming alkenes and alkynes they may have

bonds and single bonds. We use the same rules as for

but we also must give the number of the carbon which the

bond starts on. Instead of naming the carbon chain so that the

substituents have the lowest number, we now name it so that the

multiple bond has the lowest number.

Example:

3-methyl-1-butyne

Example: Draw and name 2 possible forms of butene.

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Example: Name each alkene.

Example: Name each alkyne.

Example: Draw each molecule from the name:

2-ethyl-1-pentene

4,4,5-trimethyl-2-hexyne

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3,3-dimethyl-1-butyne

2,3-dimethyl-1-butene

Saturated vs. Unsaturated

Saturated means to have the possible of a certain thing.

When we are talking about organic carbon chains, a saturated chain has

only bonds because they have the most hydrogens

while unsaturated carbon chains have at least one

or bond because those have less hydrogens. You can

change between saturated and unsaturated hydrocarbons by changing

the amount of that a carbon chain loses or gains.

Example:

# of H: # of H: Difference:

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Chain Length & Boiling Point

A very useful application of organic chemistry is petroleum separation;

petroleum is a naturally occurring or

carbon-hydrogen chain which occurs beneath the surface of Earth

which you may know as oil. It is made of up the decaying material of old

organic life forms and thus is made almost entirely of organic

molecules. Petroleum is interesting however because it is not made of

carbon chains with the . To separate

petroleum into similar length chains, a process called

is used. During this process petroleum is

and different chain lengths boil and separate from

each other because of the difference in point.

When heated, chain petroleum distillates first, while

chains distillate at higher temperatures.

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Skeletal Form

Scientists may also draw organic molecules using skeletal form. This

form uses lines and only writes in atoms which are not hydrogen or

carbon. The end of every line represents a , and we

assume they are all saturated with . To

represent double or triple bonds, extra lines are added where the bond

exists in the molecule.

Number of C Name

4 butane

Example: Draw the skeletal form for:

a) Propene b) 2-bromopropane

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Aromatic Molecules vs. Aliphatic Molecules

Organic molecules are generally divided into two categories,

and . Aliphatic molecules are simple in nature – they

may have any type of bond and can be straight, branched, or

in shape (in a circle). Conversely aromatic molecules are more complex;

they are only found in shape and have a network of

alternating and bonds.

Benzene is a special molecule in organic chemistry

with the formula . It follows aromatic rules with an

alternating single and double bond form making it different from

aliphatic compounds. Benzene is very useful because it is

and does not easily react.

Draw two forms of Benzene:

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Naming Part 4: Cyclic Compounds

To name aliphatic cyclic compounds count how many carbons make the

and use the appropriate prefix just as we have been. Then

you can start at any carbon to make the substituents or multiple bonds

have the numbers. The only add in is that you have

to put the word in front of the name for the ring.

1-methylcyclohexane 3-methyl-1-cyclohexene

If you are naming benzene, then we name the substituent followed by

benzene.

1-Fluorobenzene 1-Methylbenzene

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Functional Groups

Carbon-hydrogen chains can have other groups of atoms branched off

of them and are still organic as long as the atoms are H, O, N, S, P, F,

Br, I, or Cl. These groups that join on are known as

. These groups change how a molecule physically looks

and reacts with other chemicals. When naming molecules with

functional groups, most of the same rules as before still apply. Now

however the carbon chain must be numbered so that the functional

group is attached to the possible number carbon. The

suffix of the name also changes, depending on the functional group.

Group Name Naming Notes Example

Alcohol

Carboxylic

Acid

Ester

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Practice: Circle the functional group of each molecule and write its

IUPAC name underneath.

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Draw each molecule given the name.

2-Propanol

2-Butanol

1-Hexanol

Ethyl Butanoate

Methyl methanoate

Propyl pentanoate

Propanoic acid

Butanoic acid

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Uses of Aromatic Compounds and Functional Groups

Aromatic benzene compounds for the

most part are toxic to humans

however there are also safe ways

to use them such as in plastic

products. Benzene is also a component in many food products in very

small amounts.

Alcohols have a wide variety of

uses such as wound sterilization,

high efficiency fuel, disinfectants

(hand sanitizer), as a base for

paints, and drinks. Some alcohols are poisonous to humans, while others

are not. Carboxylic acids are often used to preserve food, in pain killer

medications, in soaps, and are also found in many citrus fruits. Esters

are used for flavourings in food products which include both tastes and

scents, and occur as a base in adhesives, paints, nail polish, and ink in

markers.

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Self-Reflection: Review the learning goals for the unit, and rate how

well you think you know the material before your test.

Skill I can do

this

I need a

little practice

I need to

practice a lot Explain the difference between

organic and inorganic compounds.

Identify where organic

molecules are sourced from.

Understand how C, N, O, H, and

halogens bond to form organic

molecules.

Identify, draw, & name alkanes,

alkenes, and alkynes.

Draw & name hydrocarbons with

halogens.

Draw & name branched isomers. Draw & name branched alkanes,

alkenes, and alkynes.

Draw molecules using structural,

condensed, and skeletal

strategies.

Identify saturated and

unsaturated carbon chains.

Explain how the process which

separates petroleum works.

Compare, name & draw cyclic

aliphatic and aromatic

compounds.

Draw and explain the special

features of benzene.

Explain what a functional group

is and identify, draw, and name

alcohols, carboxylic acids, and

esters.

Identify uses of organic

functional groups and aromatic

compounds.

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