Chapter 2 The Chemical Legacy of Human Activity Lesson 1 - Hydrocarbons Lesson 1 - Hydrocarbons Lesson 3 - Alcohols, Carboxylic Acids & Esters Lesson 3 - Alcohols, Carboxylic Acids & Esters Lesson 4 - Understanding Exposure Lesson 2 – Halogenated Hydrocarbons and CFC Lesson 2 – Halogenated Hydrocarbons and CFC

Science 30 Organic Chemistry Lesson 1 –Hydrocarbons and Benzene Rings (textbook reference – section 2.1 of Chem) Objectives: Objectives: – identify and name carbon compounds, using IUPAC nomenclature that contain up to three carbon atoms in the parent chain – list the sources of, and analyze the hazards posed by, halogenated hydrocarbons and benzene derivatives

Organic Compounds Organic chemistry – the study of compounds composed of carbon Organic chemistry – the study of compounds composed of carbon Hydrocarbons Hydrocarbons – Simples type of organic molecules – Contains carbon and hydrogen – Can have single, double or triple bonds – Can be saturated or unsaturated

Organic Compounds Hydrocarbons Hydrocarbons – Simples type of organic molecules – Contains carbon and hydrogen – Can have single, double or triple bonds – Hydrocarbons play an important role in the petroleum industry.

Naming Rules for Hydrocarbons  Single Bonds use –ane ending. Double bond use –ene ending. Triple bond use the –yne ending.  Start by finding the longest /parent chain. The double or triple bond MUST be in the parent chain.  Second, name all the branches  For alkanes, number the chain so the first branch has the lowest number possible.  For alkenes and alkynes, number the chain so that the double OR triple bond has the LOWEST possible number.  If there is more than one branch of a certain length, use the prefixes. Branches are listed in alphabetical order without the prefix (i.e. ignore the di, tri, etc. when ordering)  The location of the double OR triple bond is represented by a number, placed BEFORE the name of the LONGEST chain.

Examples: Name each compound Step 1: Longest Chain Step 2: Branches Step 3: Number parent chain Step 4: Organize names Step 5: Final name

Examples: Name each compound Step 1: Longest Chain Step 2: Branches Step 3: Number parent chain Step 4: Organize names Step 5: Final name

Examples: Name each compound CH 3 CH CH 2 Step 1: Longest Chain Step 2: Branches Step 3: Number parent chain Step 4: Organize names Step 5: Final name

Examples: Name each compound Step 1: Longest Chain Step 2: Branches Step 3: Number parent chain Step 4: Organize names Step 5: Final name

Examples: Name each compound Step 1: Longest Chain Step 2: Branches Step 3: Number parent chain Step 4: Organize names Step 5: Final name

Hydrocarbons – Hexagonal Rings Most of the hydrocarbons we looked at were in chains but they also exist in hexagonal rings Most of the hydrocarbons we looked at were in chains but they also exist in hexagonal ringshexagonal ringshexagonal rings – Use different names for the same rings the same rings Aromatic= Phenyl =Benzene Examples: benzene, Examples: benzene, tolulene, xylene, napthalene

Benzene Years ago, naturally present in gasoline Years ago, naturally present in gasoline Found to be a carcinogen – cancer causing Found to be a carcinogen – cancer causing Levels in gasoline are now legislated Levels in gasoline are now legislated If a spill occurs  leaching into ground water If a spill occurs  leaching into ground water Contaminated soil must undergo Remediation Contaminated soil must undergo Remediation – Removal and breakdown of hydrocarbons in gasoline

Benzene Rings (such as benzene) are much harder to break down as they are more stable Rings (such as benzene) are much harder to break down as they are more stable Known as POPs  Persistent Organic Pollutants Known as POPs  Persistent Organic Pollutants

Why More Stable? In linear hydrocarbons double bonds cause reactivity In linear hydrocarbons double bonds cause reactivity In rings they are actually more stable because of Resonance In rings they are actually more stable because of Resonance – Electrons shared by ALL carbons Represented by new symbol Represented by new symbol HIGHLY stable HIGHLY stable

Lesson 18 – Halogenated Hydrocarbons and CFC’s (textbook reference – section 2.1 of Chem) Objectives: Objectives: – identify and name carbon compounds, using IUPAC)nomenclature that contain up to three carbon atoms in the parent chain and a single occurrence of one type of functional group, including simple halogenated hydrocarbons (e.g., 2-chloropropane) – identify organic compounds commonly considered to be environmental pollutants; i.e., hydrocarbons, organic waste, CFCs, polychlorinated biphenyls (PCBs), dioxins and furans

Functional Groups functional group functional group – Addition of atoms other than carbon or hydrogen

Functional Groups See page 249 for more examples. See page 249 for more examples.

Halogenated Hydrocarbons Hydrocarbon that has one or more of its hydrogen's replaced by a halogen Hydrocarbon that has one or more of its hydrogen's replaced by a halogen – Cl, F, Br, I

Naming Halogenated Hydrocarbons 1.Name parent chain (METHANE) 2.Locate all halogens (4 fluorine) 3.Use halogen names – Fluorine  fluoro – Chlorine  chloro – Iodine  iodo – Bromine  bromo 4.Use prefixes for halogens (tetraflouro) – Mono, di, tri, tetra, penta, hexa 5.NAME: tetrafluoromethane F F C F F

Cl Cl C Cl Cl

Cl F F C C Cl Cl F

Halogenated Hydrocarbons Most famous  CHLOROFLUOCARBON (CFC) Most famous  CHLOROFLUOCARBON (CFC) Invented in the 1920s as a replacement for gases used in air-conditioning and refrigerants Invented in the 1920s as a replacement for gases used in air-conditioning and refrigerants Scientists discovered harmful effects to ozone by CFC’s Scientists discovered harmful effects to ozone by CFC’sharmful effects to ozoneharmful effects to ozone Ozone layer protects Earth from exposure to excessive UV Ozone layer protects Earth from exposure to excessive UV

CFCs CFCs break down in the atmosphere releasing a chlorine atom which interacts with ozone and breaks it down CFCs break down in the atmosphere releasing a chlorine atom which interacts with ozone and breaks it down CFCs break down in the atmosphere CFCs break down in the atmosphere Cl + O 3  ClO + O 2 O 3 + UV  O 2 + O (natural breakdown of ozone) O + ClO  Cl + O 2 (regenerates the free chlorine / free radical)

CFCs Result  holes in the ozone layer Result  holes in the ozone layer Particularly in the North due to the wind patterns called the polar vortex Particularly in the North due to the wind patterns called the polar vortexpolar vortexpolar vortex – P. 255 & p. 261

Protecting the Ozone Layer Montreal Protocol (p. 258) Montreal Protocol (p. 258) Decrease use of halogenated hydrocarbons containing chlorine Decrease use of halogenated hydrocarbons containing chlorine – HCFC (hydrochloroflurocarbons) are a better idea because they contain fewer chlorine atoms – HFC (hydrofluorocarbons) contain NO chlorine – Halon (possibly worse for ozone than chlorine containing compounds not under Montreal Protocol)

Other Halogenated Compounds Many types of plastics, pesticides, paints, and solvents are also halogenated compounds. (p. 259) Many types of plastics, pesticides, paints, and solvents are also halogenated compounds. (p. 259) Have a tendency not to break down – biomagnifying in the environment. Have a tendency not to break down – biomagnifying in the environment. dichlorodiphenyltrichloroethane

Homework Questions in the workbook Questions in the workbook

Lesson 19– Alcohols, Carboxylic acid, and Esters (textbook reference – section 2.2 of Chem) Objectives: Objectives: – Use IUPAC naming to identify alcohols, carboxylic acids, and esters. – Identify some of the uses in daily life of functional groups.

Alcohols Contain hydroxyl function group (R-OH) Contain hydroxyl function group (R-OH) Suffix “ol” on their names Suffix “ol” on their names – E.g. methanol, ethanol, propanol. Common uses include use as a antifreeze, fuel, beverage, solvents, hand sanitizers, and preservative. Common uses include use as a antifreeze, fuel, beverage, solvents, hand sanitizers, and preservative.

Example Problem 2.6 Draw the structure and name CH 3 CH 2 OH Draw the structure and name CH 3 CH 2 OH

Carboxylic Acids Contain TWO function groups Contain TWO function groups – Hydroxyl group (C bonded to OH) – Carbonyl function group (C double bonded to O) – Combined forms Carboxylic group – Represented as R-COOH – Suffix “-ic acid” Ex: formic acid, acetic acid (vinegar) Ex: formic acid, acetic acid (vinegar) Found in many soaps and oils. Found in many soaps and oils.

Identify the functional group

Esters Formed by reaction between a carboxylic acid and an alcohol Formed by reaction between a carboxylic acid and an alcohol During reaction water is produced During reaction water is produced Fats, fatty acids in the body are esters Fats, fatty acids in the body are esters Can be used to enhance odours Can be used to enhance odours

Naming Use a two name system made up of the acid and the alcohol (ending in –ate)

Identify the functional group Label the part that comes from the alcohol and from the carboxylic acid.

Identifying Esters

Polyesters Reaction of many alcohols and carboxylic acids Reaction of many alcohols and carboxylic acids Forms long chains Forms long chains – Towropes, t-shirts, personal flotation devices Both the carboxylic acid and the alcohols must have two functional groups so it can grow on both sides (p.276) Both the carboxylic acid and the alcohols must have two functional groups so it can grow on both sides (p.276) Other uses: polymer, plastics (p.275) Other uses: polymer, plastics (p.275)

Summary Be able to identify which type of functional group you are dealing with:

Know the Following Applications Methane: Natural gas. Not toxic, but combustible. Alkane Ethanol: Used as a fuel in combustion engines, alcoholic beverages, hand sanitizers. Ethanoic Acid (Acetic Acid): Vinegar – weak acid, used in cooking, cleaning products, industrial use for paints, solvents, and ester production. Benzene: Industrial intermediate used in production of rubber, lubricants, drugs, explosives, and pesticides. Found naturally in crude oil.

Homework READ p ! Practice: p #19, 20, 21ab, 22, 23abc, 24 Q’s: p. 278 #4, 6ab