Module 6Organic Chemistry

Name:Mark: /20

Homework packages are due on the day of the Final Test. Please check your answers provided on Weebly and mark your corrections with a different colour.http://kinggeorgemshughes.weebly.com/

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Organic Chemistry Name:

Organic Chemistry deals with compounds of carbon. The carbon may form compounds with hydrogen, oxygen nitrogen or suphur.

Bonding and Organic Compounds:1. Hydrogen must have one bond only and can never be the central atom

H-

2. Oxygen can have 2 single bonds or 1 double bond-O- O=

3. Carbon can have 4 single bonds, or one double bond and two single bonds or 2 double bonds, or one triple bond and a single bond

-C- C= =C= -C

4. Nitrogen can have 3 single bonds, or one double bond and one single bond or one triple bond

N- -N= N

Activity: If you have access to a molecular model set grab it and answer the following questions. For the most part you will be dealing only with the carbon (black) and hydrogen (white) atoms. You will be asked to construct 3 basic models. Please do not dismantle them until the end so you can compare the 3 structures.

1. What do the holes in the atoms represent?Lone pairs of electrons

2. What is the maximum number of bonds a carbon atom can have?4

3. What is the maximum number of bonds a hydrogen atom can have?1

4. Why do atoms bond with other atoms? What do they gain from this?To gain stability by pairing up lone electrons

5. Make a chain of 4 carbons all with single bonds. Fill in the remaining lone pairs with hydrogen atoms (ie. saturate the molecule with hydrogen). Draw the model below. (try and incorporate the 3-D component – remember VESPR)

How many Hydrogen atoms are used? 10 How many carbon atoms? 4

Can you devise a simple mathematical relationship between the number of carbons and the number of hydrogens? [eg. #C = (2 x # H) – 3]

or 2n +2

This represents your basic Alkane with the general formula C n H 2n+2

6. Now construct a chain of 4 carbons replacing the centre single bond with a double bond. Make the necessary changes to the hydorgens. Draw the model below from the same perspective as the model in the above question.

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How many Hydrogen atoms are used? 8 How many carbon atoms? 4Can you devise a simple mathematical relationship between the number of carbons and the number of hydrogens? (eg. #C = 2 times # H subtract 3)or 2n

This represents your basic Alkene with the general formula C n H2n

7. Finally construct a chain of 4 carbons replacing the centre single bond with a triple bond. Make the necessary changes to the number of hydrogens. Draw the model below.

How many Hydrogen atoms did you use? 6 How many carbon atoms? 4Can you devise a simple mathematical relationship between the number of carbons and the number of hydrogens? (eg. #C = 2 times # H subtract 3)Or 2n-2

This represents your basic Alkyne with the general formula C n H 2n-2

8. Describe the changes you observe as you change a bond from single to double to triple. Include such observations as number of hydrogen atoms, orientation in space etc.

The number of hydrogen atoms decreases As you change from a single to a double or triple bond, the shape changes.

Eg. A triple bond flattens or straightens the molecule

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Hydrocarbons

Aliphatics Aromatics

Alkanes CyclicsAlkynesAlkenes

Classes of Hydrocarbons:

Alkanes: A hydrocarbon where all carbon atoms are connected by single bonds General formula is CnH2n+2 where n=1,2,3… Structure can be shown in three ways

1. full structure

2. condensed structureCH3CH2CH2CH3

3. molecular structureC4H10

Naming Alkanes: the base name is determined by the number of carbons in the longest chain

Number of carbons

Structure Name Structure

1 CH4 Methane CH42 C2H6 Ethane CH3CH33 C3H8 Propane CH3CH2CH3

4 C4H10 Butane CH3CH2CH2CH35 C5H12 Pentane CH3CH2CH2CH2CH36 C6H14 Hexane CH3CH2CH2CH2CH2CH37 C7H16 Heptane CH3CH2CH2CH2CH2CH2CH38 C8H18 Octane CH3CH2CH2 CH2CH2CH2CH2CH39 C9H20 Nonane CH3CH2CH2 CH2CH2CH2CH2CH2CH310 C10H22 Decane CH3CH2CH2 CH2CH2CH2CH2CH2CH2CH3 side chains, called alkyl groups can be added to the main alkane chain. An alkane with side chains is called a substituted hydrocarbon or a branched

hydrocarbon alkyl groups are also named according to the number of carbons

Number of carbons Structure Alkyl group1 CH3 – Methyl2 CH3 – CH2 – Ethyl3 CH3 – CH2 – CH2 – Propyl4 CH3 – CH2 – CH2 – CH2 – Butyl

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Step 1: Select the longest continuous chain of carbon atoms (parent chain). This is the basic alkane and will take the alkane name for this number of carbon atoms. This is the last name of this hydrocarbon.

Eg.1 C-C-C-C-C-C Eg.2 C-C C- C Eg.3 C- C-C-C C-C-C l l l l l C-C-C C-C—C- C C-C-C-C—C- C

l l l C-C C-C C-C

Heptane hexane nonane

Step 2: All other carbons not included as part of the longest chain will take on the alkyl name. Number the longest chain so as to assign the lowest numbers to the alkyl groups attached to the main chain.

1 2 3 4 5 1 2 3 4 5 6 7 8Eg.1 CH3-CH-CH2-CH2-CH3 Eg.2 CH3CH2CH2CHCH2CH2CH2CH3

l l CH3 CH2CH3

2-methylpentane 4-ethyloctane

Step 3: Now name it in this order:1. the carbon number at which the alkyl group is attached2. a dash3. name the alkyl group4. name the parent chain

Alkyl groups placed in parenthesis after a carbon atom is attached to it.

Eg. CH3CH(CH3)CH2CH3 Eg. CH3CH2C(CH3)2CH3

2-methylbutane 2,2 - dimethylbutane

Step 4: If more than one different alkyl group is attached to a hydrocarbon then 1. list the alkyl group in alphabetical order2. precede each alkyl group by it’s number3. put a dash between each alkyl group and its number

Eg. CH3CH(CH3)CH2CH(CH2CH3)CH2CH3

4-ethyl-2-methylhexane* If an alky group is repeated then list each carbon number where the repeated group is attached, separated by commas, and prefix the repeated group name by di, tri, tetra to show how many identical groups are attached.

Eg. CH3CH(CH3)CH2CH(CH3)CH2CH(CH3)CH2CH2CH32,4,6-trimethylnonane

Name the following alkanes or substituted alkanes and find the molecular formula6

1. CH3CH2CHCH3 l CH3

______________________

2. CH3CHCH2CH2CHCH2CH3 l l CH3 CH2CH3______________________

3. CH3CH2C(CH3)CH3 l

CH2CH3_____________________4. CH2CH2CHCH2CH2 l l l CH3 CH3 CH2CH3_____________________

5. CH3CHCH2CH2CH2CH3 l CH2CH2CH3

_____________________

6. CH3CH2C(CH3)2CH3

________

Draw the following structures:

Full structure of 2,3-dimethyloctane

Condensed structure of 3,5-diethyl-,4-dimethylhexane

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Name the following alkanes and draw the full structure7. CH3CH2C(CH3)2CH2CH2CH3

8. ClCH2CH(Cl)CH(CH3)CH(CH3)2 Cl - chloro

9. CH3CH2CH2CH(CH2CH3)CH2CH2Br Br – bromo

10. Consider the name: 2-ethylpentane. Draw the structure.

Structural Isomers

Compare the following two alkanes:

C-C-C-C-C C-C-C-C l

C

Pentane 1-methylbutane

Give the molecular formula for each.

C5H12 C5H12

What do you notice?

Even though they look so different, the molecular formulas are the same

This is what you call a structural isomer. While the molecular formulas are the same, the carbons are “stuck” together different, giving the compounds different properties. Structural Isomers are considered to be different compounds.

note: the lack of hydrogens assumes each carbon is saturated with them

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Determine all the structural isomers for the following molecular formulas. Name each isomer.

1. CH4 -none2. C2H6 -none3. C3H8 -none4. C4H10

a. C-C-C-C b. C-C-C C

5. C5H12 Ca. C-C-C-C-C b. C-C-C-C c. C-C-C

C C

6. C6H14a. C-C-C-C-C-C b. C-C-C-C-C

C

C Cc. C-C-C-C-C d. C-C-C-C e. C-C-C-C C C C

7. C7H16a. C-C-C-C-C-C-Cb. C-C-C-C-C-C c. C-C-C-C-C-C

C C

C C Cd. C-C-C-C-C e. C-C-C-C-C f. C-C-C-C-C

C C C

C Cg. C-C-C-C-C h. C-C-C-C i. C-C-C-C-C

C C C CC

Cycloalkanes: are hydrocarbons where the “first” carbon connects with the “last” carbon

forming a circle. Sometimes called cyclic hydrocarbons Are named in the same way as straight chained hydrocarbons except “cyclo”

is placed in front

1. cyclopropane

or or

2. cyclobutane

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or or

3. cyclopentane

or or

4. cyclohexane

or

General formula is Cn H2n

Substituted cycloalkanes follow the same rules as straight chain alkanes except

1. if there is only one substituent it does not need to be numberedEg. Ethylcyclopentane (not 1-ethylcyclopentane)

CH3

2. if there is more than one substituent, the first one is assumed the “1” position and the remaining ones are numbered

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clockwise or counterclockwise so as to have the lowest set of numbers.

Eg. 1-ethyl-2-methylcyclohexane

CH3

CH2CH3

Eg.

Alkyl Halides: sometimes a substituent can be a halogen, and are named in the same

fashion as alkyl groups.F = fluoro Cl= chloro Br= bromo I= iodo also known as the halogroups

Eg.1 CH3-Cl

Eg. 2 CH3CHFCH3

Eg. 3 CCl3-CF3

Eg. 4. /F

Note: yet another way of illustrating hydrocarbons – at each corner sits a carbon atom which is saturated with hydrogen atoms

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Alkene Family:

Alkenes are organic compounds containing at least one double bond and is not enclosed. The general formula for the alkene family is CnH2n

Naming Alkenes:

1. Select the longest continuous carbon chain containing a double bond and use the Alkene name (like alkanes but “a” becomes “e” – eg. Butane).

2. Indicate the location of the double bond by prefixing the alkene name with the number of the C-atom starting the double bond. The double bond determines the numbering.

3. Name the subgroups as before with alkanes.

CEg1. C=C-C-C 3,3 – dimethyl – 1 – butene C6H12

C

Eg2. CH3-CH=C-CH2-CH2-CH3 3-ethyl – 2 – hexene C8H16 l CH2-CH3

CH2 ll

Eg3. CH3-CH2-C-CH2-CH3 2 – ethyl – 1 – butene C6H12

Cl l

Eg4. CH3-CH2-C-CH2-CH=CH2 4,4 – dichloro – hexene C6H10Cl2 l

Cl *don’t need to indicate location of db if on first carbon*

Isomers of Alkenes:

As you determined from your introduction to hydrocarbons, alkenes are much less flexible than alkanes because the double bond locks the structure and prevents twisting. This allows for cis-trans isomerism:

Cis-trans isomers require:1. a double bond2. groups other than hydrogen attached to each carbon involved

in the double bond

Let’s look at 2-butene:

a. b.As you can see there are 2 quite distinct models both with the name 2-butene. One has the methyl on the same side, the other has the methyl on opposite side. We use this distinction to name these structural isomers.

“a” is called cis–2–butene (same side cis)

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“b” is called trans-2-butene (transverse to each other)

See if you can visualize the following isomers:

1. cis-3-octene2. trans-4-decene3. 4-methyl-cis-2-pentene4. can 3-ethyl-3-hexene exhibit cis-trans isomerism?5. Name this compound

H CH2CH3C=C

CH3CH2CH2CH2 H

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Cycloalkenes:These are alkenes in which there is one double bond and an enclosure.

Molecular formula is CnH2n-2

cyclopropene C3H4

Cyclobutene C4H6

cylcopentene C5H8

cyclohexene C6H10

Here’s some more practice:

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The Alkyne Family: These are hydrocarbons with the general formula CnH2n-2. They are also contain one triple bond. We name them just like alkanes except we replace the “ane” ending with “yne”.

Eg1 C-C C-C-C-C 4,5-dimethyl-2-hexyne l l C C ***notice how lowest number for the triple bond

location determines the numbering***

*** It is not possible to have cycloalkynes because the triple bond limits the structure to a two dimensional plane***

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Substituted Alkanes

Not all alkanes are saturated with hydrogen. Sometimes a hydrogen or two can be replaced thus changing its characteristics and logically its name.

1) The Alcohols: Alcohols have the general formula CnH2n-1OH The functional group is comprised of an oxygen and a hydrogen (OH) The naming is the same as alkanes except we now replace the “e” with “ol” We locate the alcohol group by a preceeding number

Eg1. CH3OH methanolEg2. CH3CH2OH ethanolEg3. CH3CH2CH2OH 1-propanolEg4. CH3CHCH3 2-propanol

l OH

Eg5. CH3CH(CH3)COH 2-methyl-propanol

2) The Acids: General Formula CnH2n+1COOH The functional group is a carboxylic acid group (COOH) The naming is the same as alkans except we now replace the “e” with “oic acid”

Eg1. HCOOH methanoic acidEg2. CH3COOH ethanoic acidEg3. CH3CH2CH2COOH butanoic acid

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Aromatic Compounds: These are compounds containing a benzene ring Benzene is a six carbon, cyclic hydrocarbon with a double bond every other carbon. Benzene has the formula C6H6 Benzene can be depicted numerous different ways:

These are resonance structures of benzene Since both structures exist equally,

we use this symbol to represent benzene in all it’s forms

Naming benzene compounds is very similar to cyclic hydrocarbons

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Eg1. hydroxybenzene (also known as phenol)

Eg2. methylbenzene (also known as toluene)

Eg3. 1,4-dichlorobenzene

Esters:Esters contain a -C-O- group (COO) in the middle of a compound ll

O

Naming:1. The chains on either side of the ester derivative must be identified2. The attached to the carbon is named like alkanes except the “e” is replaced with

“oate”. The Carbon of COO is counted as part of the base name. This part of the name comes last.

3. The chain attached to the oxygen is named like any alkyl group except it stands as a word on it’s own.

Eg1. CH3CH2CHC-O-CH3 ll

O O methyl butanoate llEg2. H-C-O-CH2CH2CH2CH3 butyl methanoate

Eg3. CH3CH2COOCH2CH3 ethyl propanoate

Eg4. CH3COOCH2CH2CH3 propyl ethanoate

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Other functional groups:For the following functional groups, I don’t expect you to be able to name them, but please be able to recognize them.

Aldehyde C-H or CHOll **always at the end**O

CH3CHO OCH3CH2CHCH CH3

Ketones -C- ll **never at the end O of the chain **

CH3CCH3 O

Ethers -C-O-C-Oxygen in the middle of the chain

CH3CH2OCH2CH3

CH3CH2C(CH3)2CH2CH2OCH3Amines Contains a NH2 group CH3CH2NH2

CH3CHCH2CH2CH3 NH2

Amides -C-NH2 ll or CONH2 O

CH3CONH2

CH3C(CH3)2CH2CONH2

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15C Organic Chemistry Preparation of Soap

The term detergent refers to any substance with strong cleansing power. Detergents are commonly classified as either soaps or synthetic detergents. Synthetic detergents are prepared from synthetically produced chemicals, whereas soaps are prepared from natural fats and oils. (the word “soap” has its roots in Latin meaning “animal fat”)

The history of soap making can be traced back 5000 years to the Middle East, where it was discovered that treating fat with alkali resulted in a substance with cleansing and healing powers. In fact, for many centuries soap was used medicinally only, in the treatment of skin wounds. Soap making remained relatively primitive until 16th century when techniques that produced purer soap were developed. The reaction that produces soap is called saponification.

In more precise terms, soaps are salts of mixed fatty acids. Today they are prepared by reacting fats (which are esters) with alkali solutions such as sodium hydroxide or potassium hydroxide. For example stearin, an ester is a principal component of animal fat. It is the glycerol (1,2,3-propanetiol) ester of stearic acid, glyceryl tristearate, or stearin.

Stearin, when heated with sodium hydroxide is broken down into glycerol and sodium stearate, a soap:

In a typical commercial process, a sodium hydroxide solution is added slowly and intermittently to a molten mixture of fats and oils. High temperature and good mixing are maintained by passing steam through the mixture. After a time, the fat is broken down to form an emulsified mixture of soap, glycerol, and unreacted NaOH. At this point an NaCl solution is added, which causes the soap to separate as a curd and float to the top of the mixture. In the final stages, perfumes, colourings, antiseptics and other ingredients are added as necessary.

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Making Soap:Caution! Lye in the concentrations we will be using is extremely corrosive! (it will burn through your skin)

1. Decide with your group members what essence you want to use for your soap. If it needs to be ground use the mortor and pestel. Otherwise, just gather 15mL and put aside for step 9.

2. Put on Gloves, goggles and an apron3. Into a 1L beaker pour 425g (450mL) pomace oil4. Add 25g (28mL) castor oil5. Check the temperature of the oil. It needs to be 50oC +8 oC (42 oC -58 oC). Heat

on hotplate or bunsen burner if necessary.6. Carefully take the concentrated NaOH(lye) and check it’s temperature. It also

needs to be 50oC +8 oC (42 oC -58 oC).7. Carefully add sodium hydroxide to the pomace oil and blend/stir with a hand

blender. Blend intermittently until you have achieved a light trace.8. Go to the essence table and decide which essence you would like to add to your

soap. If necessary grind with a mortar and pestle.9. Add your essence. Approximately 15mL, or one tablespoon to your soap

mixture. 10. Carefully pour your soap into a 1L milk container. Closer the container,

carefully wrap in a towel.11. Let the neutralization occur. Your soap will be ready in about 2 weeks.12. We will remove and cut the hardened soap from the containers then.

Each station needs:1. 250mL beaker with 150mL Lye (3M NaOH)2. 1L beaker containing 425g olive oil3. 50mL beaker containing 25g castor oil4. 2 thermometers5. 10 gloves6. large black garbage bag to cover table (incase of spill)7. Mortar and pestle8. 1L milk containers9. 1 tub

Communal access:1. 2 hand blenders with extension cords2. 2 hot plates (one for reheating oil and one for lye with magnetic stirrers)3. 10 - 100mL beakers for the essence4. 10 scoopulas

Add 56g NaOH (use a clean and dry 250mL beaker) into a 1L beaker containing 150mL H2O.(to make a batch for 8 groups – 448g NaOH/1200mL H2O)

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Functional groups: Match the group below to the type of compound it represents. Just put the letter of the compound type beside the structure. (4 marks)

______

______

______

______

______

______

______

______

Draw the structure for an unsaturated hydrocarbon that has a 5 carbon chain. (1 mark)

Give the formula only for a compound containing 1 triple bond (an alkyne) with 60 carbon atoms. (1 mark)

Bonus (1 mark total)Draw the structures for: 2-pentanol

A. Ether

B. Carboxylic acid

C. Alcohol

D. Amide

E. Benzene

F. Aldehyde

G. Ketone

H. Ester

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What are the functional groups in the following over the counter drugs?

Root beer hasn't tasted the same since the use of sassafras oil as a food additive was outlawed because sassafras oil is 80% safrole, which has been shown to cause cancer in rats and mice. Identify the functional groups in the structure of safrole.

Draw the line structure of the following:

3,3-dimethylbutanoic acid 2,3-dichloro-3-pentanol

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2-ethyl-3-methyl-hexanol 1,2,3-trichlorodecanoic acid

Heptyl methanoate ethyl 3-ehtylbutanoate

Name the following compounds:

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