tyna l. meeks unit 8: organic chemistry. unit 10: organic chemistry organic chemisty – study of...

Tyna L. MeeksTyna L. Meeks

Unit 8: Organic Unit 8: Organic ChemistryChemistry

Unit 10: Organic ChemistryUnit 10: Organic Chemistry

Organic Chemisty – Organic Chemisty –

Study of carbon and most carbon Study of carbon and most carbon compounds.compounds.

Stems to a time when it was believed Stems to a time when it was believed that carbon compounds could only be that carbon compounds could only be made by living things, or organismsmade by living things, or organisms


Carbon BondingCarbon BondingIf an atom cannot lose or gain, and If an atom cannot lose or gain, and

decides to SHARE its electrons instead decides to SHARE its electrons instead a unique bond is formed…a unique bond is formed…

COVALENT bondCOVALENT bond

Sharing equally is NONPOLARSharing equally is NONPOLAR Sharing unequally is POLARSharing unequally is POLAR


Remember:Remember:COVALENT bonds cause MOLECULAR COVALENT bonds cause MOLECULAR

SUBSTANCES that exhibit the following SUBSTANCES that exhibit the following physical properties:physical properties:

low melting pointlow melting pointlow boiling pointlow boiling pointpoor conductor of heat and electricitypoor conductor of heat and electricitygenerally nonpolar, so they dissolve in generally nonpolar, so they dissolve in

nonpolar solventsnonpolar solvents


Carbon BondingCarbon Bondingsharing of 1 pair of electrons creates a sharing of 1 pair of electrons creates a

single bondsingle bondsharing of 2 pairs of electrons creates a sharing of 2 pairs of electrons creates a

double bonddouble bondsharing of 3 pairs of electrons creates a sharing of 3 pairs of electrons creates a

triple bondtriple bond


Lewis Dot Structures:Lewis Dot Structures:

HH Organic moleculesOrganic molecules

H• C •HH• C •H always forms always forms thethe

HH four bonds aroundfour bonds aroundcarbon!!carbon!!


The four bonds around carbon can be The four bonds around carbon can be arranged as:arranged as:

4 single bonds4 single bonds 2 single bonds and a double bond2 single bonds and a double bond 2 double bonds2 double bonds 1 single bond and a triple bond1 single bond and a triple bond

Unit 10: Organic ChemistryUnit 10: Organic ChemistryThe four bonds around carbon can be The four bonds around carbon can be

arranged as:arranged as:

4 single bonds - 4 single bonds - tetrahedraltetrahedral

2 single bonds and2 single bonds and

a double bond – a double bond – trigonal planartrigonal planar

2 double bonds - 2 double bonds - linearlinear

1 single bond and 1 single bond and

a triple bond - a triple bond - linearlinear


Organic molecules can be represented Organic molecules can be represented several ways:several ways:

molecular formulas: Cmolecular formulas: C33HH88

structural formulas:structural formulas:


Saturated- single bonds: all Saturated- single bonds: all carbons have as many groups carbons have as many groups as possibleas possible

AlkanesAlkanes - single bonds only - single bonds only between all carbonsbetween all carbons


Unsaturated- double or triple Unsaturated- double or triple bonds: bonds can be broken to bonds: bonds can be broken to allow for the addition of more allow for the addition of more atomsatoms

AlkenesAlkenes - double bond between - double bond between two carbonstwo carbons

AlkynesAlkynes – triple bond between – triple bond between two carbonstwo carbons


All organic molecules that have the same All organic molecules that have the same type of bonding are called type of bonding are called homologoushomologous series and can be identified by simple series and can be identified by simple formulas:formulas: Table QTable Q

Alkanes - CAlkanes - CnnHH2n+22n+2

Alkenes - CAlkenes - CnnHH2n2n

Alkynes - CAlkynes - CnnHH2n-22n-2


Learning to name our organic molecules:

Remember our single, double, and triple bonds -

Alkanes – has suffix -aneAlkenes – has suffix -eneAlynes – has suffix -yne



Prefixes for the names come from the number of carbon atoms found in molecule: Table P

1 - meth 4 - but 7 - hept2 - eth 5 - pent 8 - oct3 - prop 6 - hex 9 – non

10 - dec



Naming was based on commonalities, but a universal naming system has been established called the IUPAC system.


IUPAC Naming System

Rule 1- The longest unbranched carbon chain is called the parent chain, or parent alkane.

Rule 2- The carbon atoms in the longest chain are numbered.


IUPAC Naming System

Rule 3- The group or the alkyl group is identified by the number of the carbon it is attached to.

**Alkyl group- an alkane chain attached to a carbon in the parent chain, identify the number of carbons in the chain itself, use the prefix and add -yl


IUPAC Naming SystemRule 4- The appropriate numerical prefix (di,tri, ) is used to indicate how many times the attached group appears. A carbon atom number must be used to indicate the position of each such group. If two of the same group are attached to the same carbon atom, the number of the carbon atom is repeated.

Unit 10: Organic ChemistryUnit 10: Organic ChemistryIUPAC Naming SystemRule 5- The complete name of the compound is obtained by first naming the attach groups. Each attached group is located by the number of the carbon atom to which it is attached. The carbon number is the prefix.

Unit 10: Organic ChemistryUnit 10: Organic ChemistryIUPAC Naming SystemRule 6- non akyl groups and halogens are named with locator numbers for their position on the carbon chainRule 7- If there are two or more different

substituted groups in a name, they are arranged with the halogens given fist,

followed by alkyl groups, each in alphabetical order.


Organic molecules that have the same number Organic molecules that have the same number of carbons and hydrogens, but are of carbons and hydrogens, but are arranged arranged differentlydifferently are called are called isomersisomers..

Isomers don’t start until butane, and there are Isomers don’t start until butane, and there are two ways to draw Ctwo ways to draw C44HH1010

H H H HH H H H H H

H C C C C HH C C C C H H C HH C H

H H H HH H H H H C C C H H C C C H

H H HH H H


Isomers:Isomers: Isomers have the Isomers have the same molecular formulasame molecular formula

but but different structural formulasdifferent structural formulas - due to - due to these differences in their structure, they these differences in their structure, they have different physical properties (boiling have different physical properties (boiling points and such)points and such)

It is the ability to form isomers that is largely It is the ability to form isomers that is largely responsible for the huge number of organic responsible for the huge number of organic molecules.molecules.



Some molecules are circular, or cycloalkanes.

A very special case of these are known as

AROMATICS

Unit 10: Table RUnit 10: Table R


Organic Molecules Containing Halides

When any of the halogens replaces a hydrogen atom in an alkane, it is called an organic halides, or halocarbon

•F, Cl, Br, or I


Organic Molecules Containing Oxygen

Alcohols (ol) have the hydroxyl group –OH•Primary alcohol – has an OH attached to a carbon which is attached to only one other carbon

•Secondary alcohol - has an OH attached to a carbon which is attached to two other carbons

•Tertiary alcohol - has an OH attached to a carbon which is attached to three other carbons



Alcohols (ol) have the hydroxyl group –OH•Monhydroxy alcohol – an alcohol with only one OH Attached

•Dihydroxy alcohol - an alcohol with two OH’s Attached

•Trihydroxy alcohol - an alcohol with three OH’s attached



Aldehyde (al)- has a carbonyl group at the end of a hydrocarbon chain.

R-CHO

Ketone- has a carbonyl group on the interior of a hydrocarbon chain.

R-COR`



Carboxylic acids contain the carboxyl group (oic). –COOH



Ethers contain an oxygen atom that is bonded to two carbon atoms .

R-O-R` general formulaEthers are formed by the combination of two primary alcohols through dehydration



Esters contain an oxygen atom that is bonded to two carbon atoms AND a double bonded oxygen on the second group

R-O-OR` general formulaEsters are formed by the combination of a primary alcohol and a carboxylic acid through dehydration


Organic Molecules Containing Nitrogen

Amines are created when the addition of a -NH2 to the carbon chain takes place



Amides are created when the addition of a -NH2 to the carbon chain takes place next to a double bonded oxygen



Amino Acids:



Peptide Bonds are created when two amino acids bond together

Long chains of amino acids create peptides, and eventually,

proteins…

Unit 10: Organic ReactionsUnit 10: Organic Reactions

Combustion

CxHy + O2 CO2 + H2O + energy

This burning of fuels always releases energy (EXOTHERMIC), and the amount of energy released can be easily calculated:


Substitution: ASS

alkanes undergo substitution ONLY - substitute in a halogen (Group 17)

- break off 1 OR MORE hydrogens and put the halogen in its place,

the hydrogens will reappear in another molecule on the product side


Addition: double or triple bond present!

-break the multiple bond and add two things, one on each side of the

multiple bond


Esterification: creation of an ester

Take an organic acid AND a primary alcohol

DEHYDRATE (remove water)


Saponification: breaking down an ester

Ester + base alcohol + soap


Fermentation: make alcohol from sugar


Organic Reaction:

Polymerization: creating long chains of molecules

-addition polymerization

-condensation polymerization


Condensation Polymers The oxygen bearing organics can be made into chains as well by removing an OH from one molecule and an H from another to form WATER

CONDENSATION

Unit 10: Organic ChemistryUnit 10: Organic ChemistryEthanol has been made since ancient times by the

fermentation of sugars. All beverage ethanol and more than half of industrial ethanol is still made by this process. Simple sugars are the raw material. Zymase, an enzyme from yeast, changes the simple sugars into ethanol and carbon dioxide. The fermentation reaction, represented by the equation below:C6H12O6 2CH3CH2OH + ___CO2

a. Draw the structural formula of ethanolb. Balance the equation above

Unit 10: Organic ChemistryUnit 10: Organic Chemistry2-butanone is a manufactured chemical but it is

also present in the environment from natural sources. Nearly half of its use is in paints and petroleum based coatings because it will quickly evaporate into the air and it dissolves many substances. It is made by some trees and found in some fruits and vegetables in small amounts. It is also released to the air from car and truck exhausts.

a. Draw the structural formula of 2-butanoneb. Determine the molar mass for this moleculec. 2-butanone can dissolve or be dissolved by both

polar and nonpolar substances. Name a nonpolar liquid mentioned above.

d. Should 2-butanone be considered environmentally safe?

Unit 10: Organic ChemistryUnit 10: Organic ChemistryEthanol is an organic compound, most important of

the alcohols, chemical formula CH3CH2OH. Produced by fermentation, it is the intoxicating ingredient in alcoholic beverages. Ethanol has many uses as a solvent, raw material, extraction medium, antifreeze, antiseptic, and gasoline additive and substitute.

Butane C4H10, gaseous, a hydrocarbon that is obtained from natural gas or by refining petroleum. It can be liquefied at room temperature by compression. There are two structural formulas of butane.

a. Draw the two isomers of butaneb. Explain in terms of intermolecular forces why

ethanol has a much higher boiling point than butane.

Unit 10: Organic ChemistryUnit 10: Organic ChemistryGasoline is a mixture of hydrocarbons, one of which

is octane. Sometimes water gets into the fuel tank of the automobile. Because it can not mix with the gasoline, it sinks to the bottom of the fuel tank. In cold weather the water can sometimes freeze in the gas lines and interrupt the flow of gasoline to the engine. An additive that contains the alcohol, methanol, can be added to the fuel tank that prevents the freezing of water by forming a solution with water that won’t freeze

a. Draw the structural formula of the gasoline component, octane

b. Draw the structural formula of the gasoline additive, methanol

c. Explain why the water can dissolve in the alcohol, but not dissolve with the gasoline.

Unit 10: Organic ChemistryUnit 10: Organic Chemistry1. Draw the structural formula for ethyl acetate.

(the correct IUPAC name is ethyl ethanoate2. What is the chemical name for the alcohol that

reacts with ethanoic acid to produce ethyl ethanoate?

3. Draw a correct structural formula for dichloromethane

4. To what class of organic compounds does dichloromethane belong?

tyna l. meeks unit 8: organic chemistry. unit 10: organic chemistry organic chemisty – study of...

Documents

organic chemistrylearning

organic chemistrythe

organic chemistryunit

organic chemistryremember

single bonds tetrahedral

possiblealkanes single

double bonds linear

triple bonds alkanes