Innisfail High School

Chemistry 30

Ms. Littke

Spring 2014

Unit A: Organic Chemistry

Assessment Formative

Students must participate in lessons - complete daily notes and examples.

Students are expected to self assess and seek help if necessary Complete daily activities and review new concepts

regularly

F/S - Quizzes will be given periodically throughout the unit You should use these to your advantage as

they test smaller sections of the curriculum and help prepare you for the Unit Exam

Labs – 2 labs per unit Summative Unit Exam – test format will

be given to you later

Unit A: Chapters 9 and 10

Organic

ChemistryToday’s Objectives:

1) Define organic compounds as compounds containing carbon, recognizing inorganic exceptions such as carbonates, cyanides and carbides

2) Identify and describe significant organic compounds in daily life, demonstrating generalized knowledge of their origins and applications

3) STS: Demonstrate an understanding that science and technology are developed to meet societal needs and expand human capability

Section 9.1 (pg. 354-361)

Organic Introduction

Today’s Agenda:

1)Introduce organic chemistry and review the origins and applications of some major organic compounds

2)“Carbon – The element of life” video

3)Are You Ready pg. 354 #1-6 – due tomorrow

What is Organic Chemistry?

The early definition related to compounds obtained only from living things.

Today, it is a major branch of chemistry that deals with compounds of carbon, called ORGANIC compounds*. *Carbon compounds that are exceptions and

considered INORGANIC are compounds like: Oxides carbon monoxide (CO(g) ) and carbon dioxide

(CO2(g) ), and Ionic compounds of carbon-based ions, such as

carbonate CO32-, cyanide CN-, and carbide ions, SiC

(silicon carbide)

The major source of carbon compounds is still living or previously living things, such as plants, animals and all types of fossil fuels.

Organic or Inorganic??

Formula Organic or Inorganic?

CaCO3(s) Inorganic (carbonate ion)

C25H52(s) Organic

Ca2C(s) Inorganic (carbide ion)

CCl4(l) Organic

CH3COOH(l) Organic

CO2(g) Inorganic (oxide)

KCN(s) Inorganic (cyanide)

C12H22O11(s) Organic

Why is carbon special?

There are millions or organic compounds and only a thousand inorganic compounds. WHY? Carbon has a bonding capacity of 4

Remember Lewis Dot Diagrams from Chem 20??

This means carbon can bond extensively and can bond together to form chains effectively = called Polymerism

Carbon covalently bonds by sharing 4 pairs of electrons. These bonds may be single, double or triple, all producing stable compounds

Compounds can form with same number of each type of atom but different structures = Isomerism

So why do we care about bonding capacity? If we know how many bonding e-’s an atom has, we can

predict what structure a molecular compound will have

Determining Lewis Formulas

Atom Number ofvalence electrons

Number ofbonding electrons

Bonding capacity

carbon 4 4 4

nitrogen 5 3 3

oxygen 6 2 2

halogens 7 1 1

hydrogen 1 1 1H

I.e. Carbon can form 4 single bonds, 2 double bonds, 1 triple and 1 single, or 1 double and 2 singles

Polymers

Examples of repeating carbon chains:

Isomers

Compounds with the same number of each type of atom but different structures (C4H10)

We will talk about this in more detail later

Importance of Organic Chemistry

Building units of all living matter: carbohydrates, proteins, fats All foods are organic compounds Photosynthesis is a reaction that makes carbon a part of our

food. Carbon is passed along through food chains and sugar from photosynthesis is modified and combined with other materials.

Dead organisms are food for other organisms, or are buried in the earth and converted to fossil fuels like peat, coal and petroleum

Petroleum is the source of fuel and starting material for plastics, fabrics and industrial chemicals

The carbon cycle is an illustration of the interrelationship of all living things with the environment and with technologies that refine and use fossil fuels

We will continually outline the importance of organic compounds in our daily lives

Carbon: The Element of LifeComplete the worksheet provided as you watch the following video (20 min)

Today’s homework

Ensure video worksheet is complete and in your notes to review later

Work on Are you Ready pg. 354-355 # 1- 6 – due tomorrow

What is coming up tomorrow? Naming alkanes, branched

alkanes and cycloalkanes

Section 9.2 (pg. 366-374)

Naming Organic Compounds

Today’s Objectives:1) Name and draw structural, condensed structural, and line

diagrams and formulas for saturated and unsaturated aliphatic (including cyclic)• Containing up to 10 carbon atoms in the parent

chain/cyclic structure• Containing only one type of a functional group or multiple

bond• Using the IUPAC nomenclature guidelines

2) Identify types of compounds from the functional groups, given the structural formula

3) Define structural isomerism and relate to variations in properties

Four Types of Formulas

1. Molecular Formulas C5H10(g) Not very useful for organic compounds because so many

isomers can exist

2. Structural Formulas

3. Condensed Structural Formulas

4. Line Diagrams

– end of line segment represents carbon

– it is assumed to satisfy each carbon’s octet

Naming Organic Compounds

Aliphatic Hydrocarbons – contains only hydrogen and carbon atoms Straight line chains of carbon atoms Alicyclic hydrocarbons have carbon atoms forming a

closed ring. Still considered aliphaticAlkanes Alkenes Alkynes

Only single C-C bonds

Double C-C Bond present

Triple C-C bond present

General formula CnH2n+2

General formula: CnH2n

General formula:CnH2n-2

Saturated Unsaturated Unsaturated

In organic chemistry, names have a root and a suffix. The root describes the

number of carbons present in the chain or ring.

The suffix describes the type of compound it is.

Naming Organic Compounds

Naming Organic Compounds

Naming ALKANES

1. Find the parent chain (the longest continuous chain of carbon atoms). Use the appropriate root and the suffix-ane.

Naming ALKANES

1. Find the parent chain. Use the appropriate root and suffix.

2. Number the carbon atoms, starting from the end closest to the branch(es) so that the numbers are the lowest possible

3. Identify any branches and their location number on the parent chain (us the suffix –yl for branches)

4. Write the complete IUPAC name, following the format: (number of location, if necessary) – (branch name) (parent chain)

2-methylheptane

If more than one of the same branch exist, use a multiplier to show this (di, tri). Remember to include all numbers

Draw 2,4,6-trimethylheptane

Naming ALKANES

If different branches exist, name them in alphabetical order

ethyl before methyl (e before m in the alphabet)

Naming ALKANES

If there is more than one branch of the same type, a locating number is given to each branch and a prefix indicating the number of that type of branch is attached to the name.

This numbering prefix does not affect the alphabetical order of the branches

Draw the structural formula for 3,4-dimethylhexane

Naming ALKANES

Summary of Naming Alkanes

1. Find the parent chain. Use the appropriate root and suffix.

2. Number the parent chain carbon atoms, starting from the end closest to the branch(es) so that the numbers are the lowest possible

3. Identify any branches and their location number on the parent chain (us the suffix –yl for branches)

4. If more than one of the same branch exist, use a multiplier (di, tri) to show this. Remember to include all numbers

5. If different branches exist, name them in alphabetical order

6. Separate numbers from numbers using commas, and numbers from words using dashes (no extra spaces)

Don’t forget

Questions will specifically ask about structural, condensed structural or line structural formulas.

You must be comfortable drawing any of the three

Practice

Write the IUPAC name for the following

2,5-dimethyl-4-propyloctane

Correct the following names: 4-ethyl-2-methylpentane

ACTUALLY 2,4-dimethylhexane ALWAYS LOOK FOR LONGEST CHAIN!!

Correct the following name: 4,5-dimethylhexane

Actually 2,3-dimethylhexane **Want branch numbers to be as low as

possible

CYCLOALKANES

Based on evidence, chemists believe that organic carbon compounds sometimes take the form of cyclic hydrocarbons:

Cycloalkanes: Alkanes that form a closed ring General Formula CnH2n

Two less hydrogens are present than in straight chain alkanes because the two ends of the molecule are joined

Are these considered saturated?? Yes, because they have only single bonds and the max amount of hydrogen's bonded to the carbons

Cyclo-compounds will have a higher boiling point than their straight chain partners (because there is an additional bond present)

Cycloalkanes are named by placing the prefix cyclo in front of the alkane name, as in cyclopropane and cyclobutane

If branches are present, treat the cycloalkane as the parent chain and identify the branches.

Since there is no end at which to start the numbering, use the lowest numbers possible

Naming CYCLOALKANES

Name the following:

1. 2.

1,2-dimethylcyclopentane ethylcyclohexane

**Why don’t we need a number?

Today’s homework

Pg. 370 – 71 #7 – 11 Pg. 372 #5-6

What is coming up tomorrow? Naming Alkenes, Alkynes,

Cycloalkenes and Cycloalkynes Comparing properties of Isomers

Section 9.3 (pg. 374-380)

Naming Organic Compounds:

Alkenes and AlkynesToday’s Objectives:1) Name and draw structural, condensed structural, and line

diagrams and formulas for saturated and unsaturated aliphatic (including cyclic• Containing up to 10 carbon atoms in the parent

chain/cyclic structure• Containing only one type of a functional group or multiple

bond• Using the IUPAC nomenclature guidelines

2) Identify types of compounds from the functional groups, given the structural formula

3) Define structural isomerism and relate to variations in properties

Review:

Find and name all of the isomers of pentane (C5H12(l))

Structural Isomerism

Compound with the same molecular formula but different structures They will have different chemical and

physical properties – based on their different structures

Alkenes and Alkynes

Alkenes – hydrocarbons containing a double C-C bond General formula (CnH2n) - (like cycloalkanes)

Alkynes – hydrocarbons containing a triple C-C bond General formula (CnH2n-2) – (like cycloalkenes)

Alkenes and Alkynes are considered unsaturated compounds. They do not have the maximum number of hydrogen atoms surrounding each carbon.

Reactivity: Alkynes (highest), Alkenes, Alkanes (lowest)

Naming Alkenes and Alkynes

1. Find the parent chain. It MUST contain the multiple bond.

If the bond is a double, the suffix for the parent chain will be -ene

If the bond is a triple, the suffix for the parent chain will be –yne

2. Count carbon atoms so that the multiple bond will be on the lowest possible number. Indicate the number that the multiple bond falls on directly before the suffix

3. Name branches as before

Naming Alkenes and Alkynes

Draw the following as condensed structural formulas:

4-methylpent-2-yne

methylpropene(why don’t we need a number?)

Naming Alkenes and Alkynes

Name the following:

3-methylbut-1-ene

5-methylhex-2-ene

Naming Alkenes and Alkynes

4. It is possible for a molecule to have more than one double bond. These are called alkadienes and have the same general formula as alkynes (CnH2n-2)

If this is the case, indicate both numbers where the double bond is formed, and change the suffix to –diene.

a) Draw buta-1,3-diene:

b) What is the IUPAC name for the following:

buta-1,2-diene

Cycloalkenes and -ynes

The rules for naming cycloalkenes and cycloalkynes are the same as naming cycloalkanes The numbering for the carbon atoms begins

with the double bond; the carbons of the double bond are carbons 1 and 2; lowest numbers possible

Draw 3-methylcyclohexene as a condensed structural

formula

Today’s homework

Pg. 377 #1-5 Pg. 380 #6, 7, 11

What is coming up tomorrow? Hydrocarbon Quiz #1 Naming Aromatics Boiling point and Chemical

Properties Analysis

Section 9.4 (pg. 381-385)

Naming Organic Compounds:

AromaticsToday’s Objectives:

1) Name and draw structural, condensed structural, and line diagrams and formulas for aromatic carbon compounds• Using the IUPAC nomenclature guidelines

2) Identify types of compounds from the functional groups, given the structural formula

3) Define structural isomerism and relate to variations in properties

Hydrocarbon Quiz #1

Aromatics

Originally, organic compounds with an aroma or odour were called aromatic compounds

Now, aromatics refer to compounds containing a benzene-ring structure Benzene’s formula is C6H6, which would

suggest a highly unsaturated and reactive compound

Benzene is actually quite unreactive and is considered more stable than alkenes and alkynes

Did You Know?? Benzene is a carcinogen and is found naturally in petroleum – why would this be a problem?

What do we know about benzene? Formula is C6H6 (3D link) Unreactive – so no true double or triple

bonds Carbon-carbon bonds are the same length

and strength Each carbon is bonded to a hydrogen So what does benzene look like??

The three double bonds resonate resulting in an overall bond length somewhere in

between a single and a double bond, explaining benzene’s stability

We will use this line structural

formula to represent

benzene in compounds

Common Aromatic Compounds

Include Aspirin and Vanillin (one of the flavour molecules in vanilla) You will notice many aromatic molecules are often

depicted using a condensed structural formula except for the benzene ring, which is shown as a line structural formula.

This combination is commonly used by chemists, and we will use this method when drawing aromatics.

Naming Aromatics

1. If an alkyl branch is attached to a benzene ring, the compound is named as an alkylbenzene.

Alternatively, the benzene ring may be considered as a branch of a large molecule: in this case, the benzene ring is called a phenyl branch. Which has a phenyl branch?

An alkylbenzene Contains a phenyl branch

Naming Aromatics

2. If more than one alkyl branch is attached to a benzene ring, the branches are numbered using the lowest numbers possible, starting with one of the branches.

Given the choice between two sets of lowest numbers, choose the set that is in both numerical and alphabetical order

1-ethyl-2,4-dimethylbenzene 3-phenyl-4-propyloctane

Practice Naming Aromatics

Draw 1,2-dimethylbenzene Are there any isomers of this compound?

There is also classical way of naming these isomers. The arrangements are denoted by the prefixe:s ortho (o), meta (m) and para (p). These names are still used in industry so you may encounter them in other references.

1,2-dimethylbenzen

e

1,3-dimethylbenzen

e

1,4-dimethylbenzen

e o-dimethylbenzen

e

m-dimethylbenzen

e

p-dimethylbenzen

e

Practice Naming Aromatics

Draw the line structural formula for 1-ethyl-3-methylbenzene

Draw the line structural formula for 2-phenylpentane

Practice Naming Aromatics Draw 3-phenylpent-2-ene

Name the following propylbenzene

Why is no number needed?

Are the hydrogen’s wrong??

Summary

We have now learned about both aliphatic and aromatic hydrocarbons. You will need to be comfortable naming all of the following:

Teacher Note:

End if not enough time for two dry labs Can use during the Station Lab Periods

Review of Intermolecular Forces London Forces – temporary dipoles

resulting from an uneven distribution of e- in all molecules Temporary (-) end will repel e- in neighbouring

molecules and so on Depends on size of molecule (number of e-’s) Weakest of the intermolecular forces

Dipole-Dipole – only exists in polar molecules Attraction between + and – ends of molecule

Hydrogen Bonding – super strong force Only exists when H-N, H-F, H-O bonds are

present

Applications Read pg. 384 Lab Exercise 9.A – complete the

parts in red Purpose: To test the generalization that aromatic

hydrocarbons react like saturated rather than unsaturated hydrocarbons

Design: cyclohexane, cyclohexene and benzene are all mixed with potassium permanganate (purple). Evidence for a reaction is a change in the initial purple colour of the solution.

Prediction: Based on your current knowledge, predict the order in which the compounds will react, from least reactive to most reactive. Explain your reasoning.

Analysis: On the basis of the evidence, determine the order of the reaction rate for the three compounds.

Evaluation: Determine if your prediction was verified or falsified. Was the generalization about aromatic hydrocarbons acceptable based on the evidence? Was the purpose of the investigation accomplished?

Sample lab report for 9.A

Applications Read pg. 384 Lab Exercise 9.B – complete the parts in

red Purpose: To test the ability of the concept of London

forces to predict the relative boiling points of aliphatic and aromatic compounds (Remember: the more electrons in a compound = the

stronger the intermolecular forces = the higher the boiling point needed to pull the molecules apart)

Problem: What is the relative order of the boiling points of hexane, hex-1-ene, cyclohexane, cyclohexene, and benzene?

Prediction: Determine the number of electrons in each molecule and use these numbers to determine the order of boiling points

Analysis: On the basis of the evidence given, determine the order of the boiling points. (from lowest to highest)

Evaluation: Determine if your prediction was verified or falsified. Was the predictive power of the concept of London forces judged to be acceptable based on the evidence? Was the purpose of the investigation accomplished?

Extra Practice for Lab Reports Complete pg. 355 #6

Complete the prediction, analysis and evaluation

Remember lab report guidelines in textbook starting on pg. 790

Today’s homework

Pg. 385 #3-8 – due tomorrow

What is coming up tomorrow? Review Aromatic and Aliphatic

Compounds Refining

Section 9.5 and 9.6 (pg. 386-400)

Properties of Organic Compounds & Crude Oil

RefiningToday’s Objectives:

1) Compare boiling points and solubility of organic compounds

2) Describe fractional distillation and solvent extraction

3) Describe major reactions for producing energy and economically important compounds from fossil fuels

Physical Properties of Simple Hydrocarbons

Alkanes Non-polar moleculesOnly intermolecular forces are London ForceBoiling point and melting point increase with number of carbonsAll insoluble in water (like dissolves like) – nonpolar and polar don’t mix1-4Cs = gas, 5-16Cs = liquid 17 and up = solid at SATP

Alkenes Non-polar molecules, therefore insoluble in waterBoiling points slightly lower than alkanes with the same number of carbons due to less electrons (unsaturated), resulting in lower London Forces

Alkynes Non-polar molecules, therefore insoluble in waterIn theory boiling points slightly lower than alkenes with the same number of carbons due to less electrons (unsaturated), resulting in lower London Forces

Branching

The more branching, the less significant the London Force (~lower b.p.) - more surface area in straight chain hydrocarbons allows more separation of charge, resulting in greater London Force - see Table #3 pg. 378 (i.e. pentane (with 5Cs) has a b.p. of 36oC which is much higher than dimethylpropane (5Cs) -12oC) = because branching decreased the strength of the London force

Sample Question

Predict the relative order of boiling points of the following compounds (lowest to highest). Explain your reasoning.

butanol but-1-ene cyclobutane butanoic acid butane

Lowest -------------------------------------------------------------> Highest

but-1-ene cyclobutane butane butanol butanoic acid

Reasoning: but-1-ene has lower LF’s for than butane because it is unsaturated, cyclobutane has lover LF’s than butane, butanol has H-bonding, butanoic acid has stronger polar forces)

Which would be soluble in water? Butanol and butanoic acid – because they are the only

polar molecules and like dissolves like!

Crude Oil Refining

Crude oil is a complex mixture of hundreds of thousands of compounds, all of which have different boiling points We can take advantage of these different b.p.’s

and physically separate the different components using heat

This process is called fractional distillation or fractionation

A fractional distillation tower contains trays positioned at various levels.

Heated crude oil enters near the bottom of the tower.

The bottom is kept hot, and the temperature gradually decreases toward the top of the tower.

As compounds cool to their boiling point, they condense in the cooler trays. The streams of liquid (called fractions) are withdrawn from the tower at various heights along the tower.

Electronic Visual

Fractional Distillation Video

A more detailed look… The vaporized components of

the crude oil rise and gradually cool.

To get from one level to the next, the vapours are forced to bubble through the liquid condensed in each tray.

The figure shows the bubble caps used to allow this to happen.

If a gas cools to its boiling point, it will condense and be piped out through the draining tube

Q: How does the number of carbon atoms in a hydrocarbon chain affect its boiling point? Smaller molecules have fewer electrons, so weaker

London forces compared with larger molecules. The fractions with higher boiling points are found to contain much larger molecules (see Table 1 pg. 387)

Crude oil is heated in the fractionation tower without air being present to reduce the risk of mixtures starting

to burn or explode

Cracking

Cracking: large hydrocarbons are broken into smaller fragments

Historically, thermal cracking used extremely high temperatures but created large quantities of solid coke.

Now, catalytic cracking uses a catalyst to speed up the reaction and produce less residual products like tar, asphalt and coke Example: C17H36(l) C9H20(l) + C8H16(l) + C(s)

larger molecules smaller molecules + carbon

In 1960, hydrocracking was developed, which combines catalytic cracking and hydrogenation and produces no coke. Example: C17H36(l) + H2(g) C9H20(l) + C8H16(l)

larger molecule + hydrogen smaller molecules

Oil Refining

The refining of crude oil can be divided into two main categories:

1. Physical Processes Fractional Distillation: see previous slides Solvent Extraction: solvent is added to

selectively dissolve and remove an impurity or to separate a useful product from a mixture

2. Chemical Processes Cracking – larger molecules are broken down

into smaller ones Reforming – large molecules are formed from

smaller ones These chemical processes are needed because

fractional distillation does not produce enough of the hydrocarbons that are in demand (i.e. gasoline) and produces too much of the heavier fractions

Catalytic Reforming and Alkylation

Catalytic Reforming: improves the quality of the gasoline

aliphatic molecule aromatic molecule + hydrogen

Alkylation: increases the branching; improves the quality of the fuel

aliphatic molecule more branched molecule (AKA: isomerization because it converts molecules into a

branched isomer)FYI pg. 392 on

Octane Numbers

Combustion Reactions

Burning of hydrocarbons in the presence of oxygen Complete Combustion: abundant supply of

oxygen; products are carbon dioxide, water vapour and heat Ex. C3H8(l) + 5O2(g) 3CO2(g) + 4H2O(g)

Incomplete Combustion: limited supply of oxygen; products are carbon monoxide, soot (pure carbon) or any combination of carbon dioxide, carbon monoxide and soot in addition to water vapour and heat Ex. 2C8H18(l) + 17O2(g) 16CO(g) + 18H2O(g)

OR 2C8H18(l) + 9O2(g) 16C(s) + 18H2O(g)

** Assume complete combustion unless specified otherwise

Balancing FYI

Ex. 2C8H18(l) + 17O2(g) 16CO(g) + 18H2O(g)

Can also be balanced using a fraction (you need to be

comfortable using this method) – divide each number by 2

C8H18(l) + 17/2 O2(g) 8CO(g) + 9H2O(g)

Ex. 2C8H18(l) + 9O2(g) 16C(s) + 18H2O(g)

can also be balanced as …

C8H18(l) + 9/2 O2(g) 8C(s) + 9H2O(g)

Simple Distillation

Today’s homework Read pages 410-416 Pg. 391 #9, 11 - 13 Pg. 397 #1, 4, 5, 8, 12, 13 Read pages 410-416

What is coming up tomorrow? Chapter 9 Exam Review (Unit A Part

1) Exam on Friday Functional Groups and Hydrocarbon

Reactions Halides, alcohols, carboxylic acids, esters

and polymers Addition, Substitution and Elimination,

esterfication and polymerization

Aliphatic and Aromatic Compounds

Hydrocarbon Quiz #2

Section 10.2 and 10.3 (pg. 417-435)

Organic Chemistry:Organic Halides and

Alcohols Today’s Objectives:

1) Name and draw structural, condensed structural and line diagrams and formulas for organic halides and alcohols

2) Identify types of compounds from their functional groups, given the structural formula and name of the functional groups

Today’s Agenda: Review

You will have another Hydrocarbon Quiz next class covering all aliphatic and aromatic compounds

Today’s agenda: Review Quiz – go over common

mistakes Pg. 385 #6-8

**7d) 4-methyl (not 3-methyl) Make the change in your book if not

done already

Review of Intermolecular Forces London Forces – temporary dipoles

resulting from an uneven distribution of e- in all molecules Temporary (-) end will repel e- in neighbouring

molecules and so on Depends on size of molecule (number of e-’s) Weakest of the intermolecular forces

Dipole-Dipole – only exists in polar molecules Attraction between + and – ends of molecule

Hydrogen Bonding – super strong force Only exists when H-N, H-F, H-O bonds are

present

Organic Halides

Organic compounds where one or more hydrogen has been replaced with halogens (F, Cl, Br, I) Common example: CFC

(chlorofluorocarbons)

Nomenclature is similar to naming branch chains of hydrocarbons, but the branch name used is based on the halogen used chloro-, fluoro-, bromo-, iodo-

Organic Halides

What do you need to know about organic halides? May by polar or nonpolar molecules or may

have a relatively nonpolar (hydrocarbon) end and a polar (halide) end (**Remember Electronegativity differences)

Have higher boiling points than similar hydrocarbons

Have very low solubility in water but higher solubility than similar hydrocarbons

Are typically good solvents for organic materials such as fats, oils, waxes, gums, resins or rubber

Usually toxic or ecologically damaging (DDTs and PCBs)

Practice Naming Organic Halides

Draw 1,2-dichloroethane

Draw 2,2,5-tribromo-5-methylhexane

Practice Naming Organic Halides

Name the following: CH2Cl2

1,2-dibromoethene

Bonus: Try 1,2-dibromo-1,2-dichloroethene

chlorobenzene

dichloromethane

Did You Know?

There is always a new concept to learn that extends what you have already learned.

In addition to the structural isomers that you know about, there are cis and trans isomers

Alcohols

An alcohol is an organic compound that contains the –OH functional group (hydroxyl) General formula is R-OH (R = rest of molecule)

Alcohols are classified as primary, secondary or tertiary depending on the number of carbons bonded to the carbon that contains the hydroxyl group

Common Alcohols

Methanol (also called wood alcohol) is extremely toxic, causing death and blindness

Ethanol (also known as grain alcohol) is the alcohol found in alcoholic beverages and is used in the production of vinegar

Gas line antifreeze, windshield de-icer, windshield washerfluid – all containmethanol

Naming Alcohols

1. Locate the longest chain that contains an –OH group attached to one of the carbon atoms. Name the parent alkane

2. Replace the –e at the end of the name of the parent alkane with –ol (i.e. butane becomes butanol)

3. Add a position number before the suffix –ol to indicate the location of the –OH group

REMEMBER to number the main chain of the hydrocarbon so that the hydroxyl group has the lowest possible position number

propan-1-ol

Naming Alcohols

4. If there is more than one –OH group (called polyalcohols), leave the –e in the name of the parent alkane and put the appropriate prefix before the suffix –ol (i.e. diol, triol, tetraol)

5. Name and number any branches on the main chain. Add the names of these branches to the prefix.

Draw 2,3-dimethylbutan-2-ol

Practice Naming Alcohols

Draw line structural formulas for:

1. cyclohexanol

2. phenol

3. The three isomers of C5H11OH that are pentanols

These are the only two cyclic or aromatic alcohols you will need to

know as they get very complicated

Alcohols

What do you need to know about alcohols?Question: Why is the propane used in a barbecue a gas at room temperature, but propan-2-ol (also known as rubbing alcohol) a liquid at room temperature?

Answer: Propane is a non-polar hydrocarbon with weak intermolecular forces, thus it has a low boiling point and is a gas at room temperature.

Propan-2-ol is an alcohol, with a polar hydroxyl group and strong intermolecular forces, thus it has a higher boiling point than propane and is a liquid at room temperature

Alcohols

What do you need to know about alcohols?Question: Glycerol (propane-1,2,3-triol) is more viscous than water, and can lower the freezing point of water. When added to biological samples, it helps to keep the tissues from freezing, thereby reducing damage. From your knowledge of the molecular structure of glycerol, suggest reasons to account for these properties of glycerol.

Answer: Each molecule of glycerol contains three hydroxyl groups which can hydrogen-bond with water, interfering with the attractions between water molecules and thus interfering with the freezing of water. When water in tissues does not freeze, there is less damage to the tissues.

Application Question

Predict the order of increasing boiling points for the following compounds, and give reasons for your answer.

butan-1-ol pentane 1-chlorobutane

Answer: (Lowest b.p.): pentane, 1-chlorobutane, butan-1-ol

Why? All molecules have a similar number of electrons. Pentane has the lowest boiling point, because it is non-polar so will only have London forces between the molecules. 1-chlorobutane is polar so will have dipole-dipole forces as well as London forces. Butan-1-ol has the highest boiling point because its molecules will have all three intermolecular forces, most importantly, hydrogen bonding

Today’s homework

Pg. 418 #1-5 Pg 424 #2-3 Pg. 430 #5,6,7,8

Due tomorrow

What is coming up tomorrow? Carboxylic Acids and Esters

Section 10.4 (pg. 436-443)

Organic Chemistry:Carboxylic Acids and

EstersToday’s Objectives:

1) Name and draw structural, condensed structural and line diagrams and formulas for carboxylic acids and esters

2) Identify types of compounds from their functional groups, given the structural formula and name of the functional groups

Carboxylic Acids

A carboxyl group is composed of a carbon atom double bonded to an oxygen atom and bonded to a hydroxyl group (-COOH) Note: Because the carboxyl group involves

three of the carbon atom’s four bonds, the carboxyl is always at the end of a carbon chain or branch

methanoic acid ethanoic acid

Examples:

Carboxylic acids are weak organic

acids

Naming Carboxylic Acids

1. Name the parent alkane

2. Replace the –e at the end of the name of than parent alkane with –oic acid

3. The carbon atoms of the carboxyl group is always given position number 1. Name and number the branches that are attached to the compound.

Draw 3-methylbutanoic acid

HOOC

Remember COOH or HOOC can also

represent the carboxyl group

Naming Carboxylic Acids

1. Draw trichloroethanoic acid (key ingredient in chemical peels)

CCl3COOH

2. Draw 3-propyloctanoic acidDo you need the CH3 here? No – but sometimes you will see it written this way. Don’t be confused because it doesn’t change the meaning

Esters

The reaction between a carboxylic acid and an alcohol produces an ester molecule and a molecule of water This reaction is known as a condensation or

esterification reaction

The ester functional group –COO– is similar to that of a carboxylic acid, except that the H atom of the carboxyl group has been replaced by a hydrocarbon branch.

Esters are responsible for natural and artificial fragrance and flavourings in plants and fruits.

In naming an ester you have to recognize that an ester has 2 distinct parts. The main part contains the C=O group which comes from the parent acid. The second part is the alkyl group.

Esters

Naming Esters

1. Identify the main part of the ester, which contains the C=O group. This part comes from the parent acid.

2. Begin by naming the parent acid but replace the –oic acid ending of the name with –oate. (propanoic acid becomes propanoate)

3. The second part is the alkyl group that is attached to the single oxygen atom. Name this as you would any other alkyl group (in this case = methyl)

4. Put the names together. Note that esters are named as two words.

Naming Esters

Name the following ester and the acid and alcohol from which it can be prepared.

ethyl butanoate

ethanol

butanoic acid

water

Tip: The branch attached to the oxygen (of the –COO) comes first in the name, the chain attached to the carbon (of the –COO) comes second

A strong acid catalyst, such as H2SO4(aq) is used along with some

heating to increase the rate of the

organic reaction

Naming Esters

Name the following ester and the acid and alcohol from which it can be prepared.

ethyl benzoate

ethanol

benzoic acid

water

Today’s homework

Pg. 438 #1,2 Pg. 441 #3-4

Due tomorrow

What is coming up tomorrow? Organic Reactions Summary and Review of all organic

molecules Full Naming Quiz (in two days)

Physical Properties of Hydrocarbon Derivatives

Alcohols Much higher boiling points than hydrocarbons (1-12Cs are liquids at SATP) due to hydrogen bonding between hydroxyl groups of adjacent moleculesSmall alcohols are totally miscible in water, but the larger the hydrocarbon part of the alcohol (nonpolar part), the more nonpolar the alcohol is

Carboxylic Acids

Like alcohols they have hydrogen bonding, but is more significant due to the C=O. This means greater bps and solubility than alcohols with same number of Cs.

Carboxylic acids with 1-4Cs arecompletely miscible in water

Esters Fruity odour in some casesPolar but they lack the –OH bond therefore do not have hydrogen bonding, so lower bps than both alcohols and carboxylic acidsEsters with few carbons are polar enough to be soluble in water

Compound Boiling Point (oC)

butane -0.5

butan-1-ol 117.2

butanoic acid

165.5

Summary Table - OrganicComplete the summary table of all of the organic compounds we have studied. This will be a good page to reference when studying

Section 10.2,10.3 and 10.4 (pg. 419-444)

Hydrocarbon Reactions:Addition, Substitution and

EliminationToday’s Objectives:

1) Define, illustrate and provide examples of simple addition, substituion, elimination and esterification (condensation)

2) Predict products and write and interpret balanced equations for the above reations

All Organic Compounds

Functional Groups Quiz

Hydrocarbon Reactions

1. Addition alkenes and alkynes + H2(g) alkanes (hydrogenation)alkenes and alkynes + HX (or X2) organic halides

2. Substitutionalkanes and aromatics + X2 organic halides

3. Eliminationalcohols alkenes + water (dehydration)

organic halides + OH- alkenes + halide ion + water

4. Esterification (already covered, just review) carboxylic acid + alcohol ester + water

5. Polymerization – monomer + monomer = polymer

addition and condensation

1. Addition Reactions: reaction of alkenes and alkynes with hydrogen gas, a halogen compound, a hydrogen halide compound or water.

Addition reactions usually occur in the presence of a catalyst

a) Addition with H2(g) (also called hydrogenation)

1. Addition Reactions: reaction of alkenes and alkynes with hydrogen gas, a halogen compound, a hydrogen halide compound or water

b) Addition of a halogen

Since addition reactions involving multiple bonds are

very rapid, the alkene product 1,2-

dibromoethene can easily undergo a

second addition step to produce 1,1,2,2-

tetrabromomethane.

Excess bromine promotes this second

step.

1,2-dichloroethane is a useful solvent and is

used to produce chloroethene, the monomer used to

make PVC.See Pg. 417 equation

1. Addition Reactions: reaction of alkenes and alkynes with hydrogen gas, a halogen compound, a hydrogen halide compound or water

c) Addition of an HX (hydrogen halide) molecule Show both possible isomers when predicting the

products

The addition of hydrogen halides (HF, HCl, HBr or HI) to unsaturated compounds can produce structural

isomers, since the hydrogen halide molecules can add in different orientations. However, the type of isomers

produced are not always equal.

For example only a tiny amount of 1-chloropropane is produced compared to 2-chloropropane in the above

reaction.

Practice Addition Reactions

For each of the following questions, draw condensed structural diagrams and name all products

1. ethene + bromine

2. hydrogen chloride + ethene

3. 3-methylbut-1-yne + excess hydrogen

1,2-dibromoethane

chloroethane

__2-

methylbutane

2. Substitution Reactions – breaking of a C-H bond in an alkane or an aromatic ring and replacing it with another atom or group of atoms

Usually occur slowly at room temperature, so light may be necessary as a catalyst

Often substitutes a halogen for a hydrogen No change in saturation

Propane contains hydrogen atoms bonded to end carbons and the middle carbon atom, so two different products (isomers) are

formed, in unequal proportions

2. Substitution Reactions – breaking of a C-H bond in an alkane or an aromatic ring and replacing it with another atom or group of atoms

Benzene rings are stable, like alkanes, so they react slowly with halogens, even in the presence of light.

As with alkanes, further substitution can occur in benzene rings, until all hydrogen atoms are replaced by halogen atoms

(in the presence of excess halogens)

Practice Substitution Reactions

For each of the following questions, draw condensed structural diagrams and name all products

1. propane + fluorine

2. ethane + chlorine

1-fluoropropane + 2-fluoropropane + hydrogen

fluoride

chloroethane + hydrogen chloride

H - FF - F

3. Elimination Reactions – involves eliminating atoms or groups of atoms from adjacent carbon atoms; decreases the level of saturation

a) Alkane cracked into an alkene (uses high temperatures)

b) Alcohol is reacted with a catalyst to produce an alkene and water (dehydration – removes a water molecule from the alcohol)

c) Alkyl halide reacts with a hydroxide ion (OH-) to produce an alkene (dehydrohalogenation – removes a hydrogen and halogen atom)

Practice Elimination Reactions

Write a structural formula equation for the preparation of but-2-ene from chlorobutane, in the presence of a strong base

Write a structural formula equation for the preparation of but-2-ene from butan-2-ol

Reaction type

Complete Combustion

Addition Elimination Substitution Esteri-fication

Reactants Hydrocarbon* + O2

ene or yne + HOH, X2, HX, or H2

alcohol or alkyl halide

alkane or aromatic + X2

alcohol + carboxylic acid

Products CO2(g) + H2O(g) or (l)

alcohol, alkyl halide*, alkane

alkene + HOH or HX

alkyl halide ester + water

Other triple or double to single

single to double

slow; needs uv light

acid catalyst needed

Other more bonds*

fewer bonds*

Today’s homework

Pg. 422 #7,8 (Addition and Substitution) Pg. 433 #18-19 (Elimination) Pg. 443 #1, 5-8 (Esterfication)

What is coming up tomorrow? Polymerization STS Connections

Section 10.5 (pg. 445-459)

Organic Chemistry: Polymerization Reactions

Today’s Objectives:

1) Define, illustrate, and give examples of monomers, polymers, and polymerization in living and non-living systems

STS: 2) Illustrate how science and technology are developed to meet societal needs and expand human capabilities

STS: 3) Illustrate how science and technology have both intended and unintended consequences

Polymerization

Polymers are large molecules made of chains of monomers, small molecules that link together. Polymerization is the

formation of polymers from these small units

Polymers can occur naturally (proteins, carbohydrates) and can be synthesized (nylon, Teflon, polyethylene)

They play an integral part in the function of life systems and have revolutionized the way society functions

Polymerization Video

Addition Polymerization

Many plastics (synthetic polymers) are made by this process

The polymerization process is initiated with a free radical (a species with an unpaired electron). The free radical attacks and breaks the double bond forming a new free radical that attacks another monomer

Addition Polymerization always results in one product, the polymer Requires unsaturated hydrocarbon monomers and

bond saturation occurs when the polymer is made Common polymers produced by addition

polymerization:

Things to know about addition

polymers…

The polymer names end in –ene (i.e. polystyrene, polypropene). Does this mean they have double bonds? No, the double bonds are saturated by adjacent

monomers, as the polymer is made. The name refers to the starting monomer (i.e. polyethene is started by the monomer ethene)

What properties make Teflon a good product for non-stick materials? Teflon is made up of C-F bonds which are very strong (not

C-H bonds). These very strong bonds make the Teflon highly unreactive (non-sticking), it has a high melting point and it has a slippery surface

Condensation Polymerization Monomers combine to form a polymer and a bi-

product. Each time a bond forms between monomers, small molecules, such as water, ammonia, or HCl are “condensed” out.

The polymerization of nylon:• For condensation

polymerization to occur, monomers must be bifunctional, meaning they have at least two functional groups.

• If they only had one functional group, then only one bond would form.

Condensation Polymerization Condensation polymerization also produces

natural polymers, called proteins. Amino acids (monomers) polymerize to make

peptides (short chains of amino acids) or proteins (long chains of amino acids)

Comparison of Addition and Condensation Polymerization

Needs a double or triple bond in the monomer

Produces only one product, the polymer

Needs bifunctional monomers (have two functional groups)

Produces two products: the polymer and the biproduct (water, ammonia or HCl)

Addition Condensation

Polyester When a carboxylic acid reacts with an alcohol in an

esterification reaction, a water molecule is eliminated and a single ester molecule is formed.

This esterification reaction can be repeated so many esters are joined in a long chain… a polyester This is created using a dicarboxylic acid (an acid with a

carboxyl group at each end) and a diol (an alcohol with a hydroxyl group at each end)

The ester linkages are formed end to end between alternating acid and alcohol molecules

Polyester: Dacron

Another example of a polyester: Note the two carboxyl groups in the

dicarboxylic acid and the two hydroxyl groups in the polyalcohol that start the chain reaction

Natural Polymer Examples

Starch, wood, silk, DNA

Today’s homework

Pg. 448 #2-4 Pg. 452 #13 Pg. 455 #16, 17

Due tomorrow

What is coming up tomorrow? Stations Lab – will take two days

Chemistry 30 Organic ReviewUnit Exam

Learning Tip Pg. 441