A guide for GCSE students KNOCKHARDY PUBLISHING ORGANIC CHEMISTRY A guide for GCSE students 2010 SPECIFICATIONS KNOCKHARDY PUBLISHING

ORGANIC CHEMISTRY INTRODUCTION www.knockhardy.org.uk This Powerpoint show is one of several produced to help students understand selected GCSE Chemistry topics. It is based on the requirements of the AQA specification but is suitable for other examination boards. Individual students may use the material at home for revision purposes and it can also prove useful for classroom teaching with an interactive white board. Accompanying notes on this, and the full range of AS and A2 Chemistry topics, are available from the KNOCKHARDY WEBSITE at... www.knockhardy.org.uk All diagrams, photographs and any animations in this Powerpoint are original and created by Jonathan Hopton. Permission must be obtained for their use in any work that is distributed for financial gain.

ORGANIC CHEMISTRY CONTENTS What is organic chemistry? Hydrocarbons Alkanes Alkenes Alcohols Industrial preparation of alcohols Carboxylic acids and esters Questions

ORGANIC CHEMISTRY DISTILLATION OF CRUDE OIL THE PETROCHEMICAL INDUSTRY This Powerpoint presentation does not cover… DISTILLATION OF CRUDE OIL THE PETROCHEMICAL INDUSTRY POLYMERS For further information on these topics, please see the other Powerpoints on the Knockhardy GCSE site.

ORGANIC CHEMISTRY WHAT IS IT?

ORGANIC CHEMISTRY WHAT IS IT? Organic chemistry is the study of carbon compounds. It is such a complex branch of chemistry because...

ORGANIC CHEMISTRY WHAT IS IT? Organic chemistry is the study of carbon compounds. It is such a complex branch of chemistry because... • CARBON ATOMS FORM STRONG COVALENT BONDS TO EACH OTHER

ORGANIC CHEMISTRY WHAT IS IT? Organic chemistry is the study of carbon compounds. It is such a complex branch of chemistry because... • CARBON ATOMS FORM STRONG COVALENT BONDS TO EACH OTHER • THE CARBON-CARBON BONDS CAN BE SINGLE, DOUBLE OR TRIPLE

ORGANIC CHEMISTRY WHAT IS IT? Organic chemistry is the study of carbon compounds. It is such a complex branch of chemistry because... • CARBON ATOMS FORM STRONG COVALENT BONDS TO EACH OTHER • THE CARBON-CARBON BONDS CAN BE SINGLE, DOUBLE OR TRIPLE • CARBON ATOMS CAN BE ARRANGED IN STRAIGHT CHAINS BRANCHED CHAINS and RINGS

ORGANIC CHEMISTRY WHAT IS IT? Organic chemistry is the study of carbon compounds. It is such a complex branch of chemistry because... • CARBON ATOMS FORM STRONG COVALENT BONDS TO EACH OTHER • THE CARBON-CARBON BONDS CAN BE SINGLE, DOUBLE OR TRIPLE • CARBON ATOMS CAN BE ARRANGED IN STRAIGHT CHAINS BRANCHED CHAINS and RINGS • OTHER ATOMS/GROUPS OF ATOMS ARE PLACED ON CARBON ATOMS

ORGANIC CHEMISTRY WHAT IS IT? Organic chemistry is the study of carbon compounds. It is such a complex branch of chemistry because... • CARBON ATOMS FORM STRONG COVALENT BONDS TO EACH OTHER • THE CARBON-CARBON BONDS CAN BE SINGLE, DOUBLE OR TRIPLE • CARBON ATOMS CAN BE ARRANGED IN STRAIGHT CHAINS BRANCHED CHAINS and RINGS • OTHER ATOMS/GROUPS OF ATOMS ARE PLACED ON CARBON ATOMS

You can also get a combination of rings and chains ORGANIC CHEMISTRY CHAINS AND RINGS CARBON ATOMS CAN BE ARRANGED IN STRAIGHT CHAINS BRANCHED CHAINS and RINGS You can also get a combination of rings and chains

SINGLE AND MULTIPLE BONDING ORGANIC CHEMISTRY SINGLE AND MULTIPLE BONDING CARBON-CARBON COVALENT BONDS CAN BE SINGLE, DOUBLE OR TRIPLE

Compounds containing only carbon and hydrogen atoms HYDROCARBONS Compounds containing only carbon and hydrogen atoms

HOMOLOGOUS SERIES A FAMILY OF COMPOUNDS WHICH HAVE… ● A GENERAL FORMULA ● SIMILAR CHEMICAL PROPERTIES

HOMOLOGOUS SERIES A FAMILY OF COMPOUNDS WHICH HAVE… ● A GENERAL FORMULA ● SIMILAR CHEMICAL PROPERTIES Examples:-

HOMOLOGOUS SERIES A FAMILY OF COMPOUNDS WHICH HAVE… ● A GENERAL FORMULA ● SIMILAR CHEMICAL PROPERTIES Examples:- ALKANES CnH2n+2 CH4 C2H6

HOMOLOGOUS SERIES A FAMILY OF COMPOUNDS WHICH HAVE… ● A GENERAL FORMULA ● SIMILAR CHEMICAL PROPERTIES Examples:- ALKANES CnH2n+2 CH4 C2H6 ALKENES CnH2n C2H4 C3H6

WHAT ARE THE NEXT IN EACH SERIES? HOMOLOGOUS SERIES WHAT ARE THE NEXT IN EACH SERIES? ALKANES ALKENES CH4 C2H6 C2H4 ? C3H6 ? ? ? ?

WHAT ARE THE NEXT IN EACH SERIES? HOMOLOGOUS SERIES WHAT ARE THE NEXT IN EACH SERIES? ALKANES ALKENES CH4 C2H6 C2H4 C3H8 C3H6 C4H10 C4H8 C5H12 C5H10

SATURATED HYDROCARBONS ALKANES SATURATED HYDROCARBONS

ALKANES WHAT ARE THEY? ● HYDROCARBONS ● CARBON ATOMS ARE JOINED BY SINGLE COVALENT BONDS ● CONTAIN THE MAXIMUM NUMBER OF HYDROGEN ATOMS ● ARE SATURATED HYDROCARBONS

ALKANES WHAT ARE THEY? ● HYDROCARBONS ● CARBON ATOMS ARE JOINED BY SINGLE COVALENT BONDS ● CONTAIN THE MAXIMUM NUMBER OF HYDROGEN ATOMS ● ARE SATURATED HYDROCARBONS ● EXAMPLES… METHANE CH4 ETHANE C2H6 PROPANE C3H8 BUTANE C4H10 GENERAL FORMULA IS… CnH2n+2

ALKANE STRUCTURES H H – C – H METHANE ETHANE PROPANE CH4 C2H6 C3H8

ALKANE STRUCTURES H H – C – H H H H – C – C – H METHANE ETHANE PROPANE CH4 C2H6 C3H8

METHANE ETHANE PROPANE CH4 C2H6 C3H8 ALKANE STRUCTURES H H – C – H H H H – C – C – H H H H H – C – C – C – H METHANE ETHANE PROPANE CH4 C2H6 C3H8 THESE ARE DISPLAYED STRUCTURES THEY SHOW ALL THE COVALENT BONDS IN THE MOLECULE Each covalent bond is represented by a line

ALKANE STRUCTURES H H – C – H H H H – C – C – H H H H H – C – C – C – H METHANE ETHANE PROPANE CH4 C2H6 C3H8 H H H H H – C – C – C – C – H BUTANE C4H10

ALKANE STRUCTURES HOWEVER H – C – H H H H – C – C – H H H H H – C – C – C – H METHANE ETHANE PROPANE CH4 C2H6 C3H8 H H H H H – C – C – C – C – H BUTANE C4H10 HOWEVER By the time you get to butane, there are two ways to arrange the carbon and hydrogen atoms…

C4H10 ALKANE STRUCTURES H H – C – H H – C ––– C ––– C – H H H H H – C – C – C – C – H BUTANE METHYLPROPANE STRUCTURAL ISOMERS Compounds with the SAME MOLECULAR FORMULA but DIFFERENT STRUCTURAL FORMULA

THESE ARE ALL THE SAME STRUCTURE ALKANE STRUCTURES H H H H H C C C C H H H H H BEWARE! THESE ARE ALL THE SAME STRUCTURE H H C H H H C C H H H C H H H H H C C C H H H H C H H

HOW MANY ISOMERS ARE THERE? ISOMERS OF PENTANE C5H12 HOW MANY ISOMERS ARE THERE?

ISOMERS OF PENTANE C5H12 THERE ARE 3 ISOMERS

ISOMERS OF PENTANE H H H H H C5H12 H C C C C C H H H H H H THERE ARE 3 ISOMERS

ISOMERS OF PENTANE H H H H H C5H12 H C C C C C H H H H H H H H H H THERE ARE 3 ISOMERS H H H H H C C C C H H H H H C H H

ISOMERS OF PENTANE H H H H H C5H12 H C C C C C H H H H H H H H H H H H THERE ARE 3 ISOMERS H H H C C C H H C H H H H H H H C C C C H H H H H C H H

SOME PROPERTIES OF ALKANES

SOME PROPERTIES OF ALKANES Boiling point increases as they get more carbon atoms in the formula CH4 (-161°C) C2H6 (-88°C) C3H8 (-42°C) C4H10 (-0.5°C)

SOME PROPERTIES OF ALKANES Boiling point increases as they get more carbon atoms in the formula CH4 (-161°C) C2H6 (-88°C) C3H8 (-42°C) C4H10 (-0.5°C) Viscosity Greater number of C atoms = greater viscosity Flammability Greater number of C atoms = less flammable

SOME PROPERTIES OF ALKANES Boiling point increases as they get more carbon atoms in the formula CH4 (-161°C) C2H6 (-88°C) C3H8 (-42°C) C4H10 (-0.5°C) Viscosity Greater number of C atoms = greater viscosity Flammability Greater number of C atoms = less flammable Use as fuels Alkanes make useful fuels CH4 + 2O2 CO2 + 2H2O

SOME PROPERTIES OF ALKANES Boiling point increases as they get more carbon atoms in the formula CH4 (-161°C) C2H6 (-88°C) C3H8 (-42°C) C4H10 (-0.5°C) Viscosity Greater number of C atoms = greater viscosity Flammability Greater number of C atoms = less flammable Use as fuels Alkanes make useful fuels The more carbon atoms they have the more oxygen they need CH4 + 2O2 CO2 + 2H2O C3H8 + 5O2 3CO2 + 4H2O

UNSATURATED HYDROCARBONS ALKENES UNSATURATED HYDROCARBONS

ALKENES WHAT ARE THEY? ● HYDROCARBONS ● CONTAIN A DOUBLE C=C COVALENT BOND ● ARE UNSATURATED HYDROCARBONS – THEY CAN HAVE ATOMS ADDED TO THEM ● ARE MORE REACTIVE THAN ALKANES

ALKENES WHAT ARE THEY? ● HYDROCARBONS ● CONTAIN A DOUBLE C=C COVALENT BOND ● ARE UNSATURATED HYDROCARBONS – THEY CAN HAVE ATOMS ADDED TO THEM ● ARE MORE REACTIVE THAN ALKANES ● EXAMPLES… ETHENE C2H4 PROPENE C3H6 BUTENE C4H8 GENERAL FORMULA IS… CnH2n

C C C C C H H H ALKENE STRUCTURES H H H H H ETHENE PROPENE C2H4 C3H6 DOUBLE COVALENT BOND H H C C H H H C C C H H H ETHENE PROPENE C2H4 C3H6

HOW CAN YOU TELL THEM APART? ALKANES & ALKENES HOW CAN YOU TELL THEM APART? ADD BROMINE WATER; if the reddish-brown colour is removed the substance possesses a C=C bond. A B C PLACE A SOLUTION OF BROMINE IN A TEST TUBE ADD THE HYDROCARBON TO BE TESTED AND SHAKE IF THE BROWN COLOUR DISAPPEARS THEN THE HYDROCARBON IS AN ALKENE A B C

C2H4 + Br2 C2H4Br2 H C C H H C C H H H H H ADDITION REACTIONS Br Br BROMINE C2H4 + Br2 C2H4Br2 Br Br H C C H H H Br Br H C C H H H ETHENE 1,2-DIBROMOETHANE THIS REACTION IS USED AS A TEST FOR UNSATURATION - BROMINE WATER IS ‘DECOLOURISED’.

C2H4 + H2 C2H6 H C C H H C C H ADDITION REACTIONS H H H H HYDROGEN CATALYST C2H4 + H2 C2H6 H H H C C H H H H C C H ETHENE ETHANE VEGETABLE OILS CONTAINING UNSATURATED FATS ARE HARDENED TO FORM MARGARINE THIS WAY

POLYMERISATION For more detailed information on POLYMERS, please see the appropriate Powerpoint on the Knockhardy GCSE site. www.knockhardy.org.uk/gcse.htm

POLYMERISATION • during polymerisation, alkenes undergo an addition reaction • all the atoms in the original alkenes are used to form the polymer • long hydrocarbon chains are formed

POLYMERISATION • during polymerisation, alkenes undergo an addition reaction • all the atoms in the original alkenes are used to form the polymer • long hydrocarbon chains are formed

POLYMERISATION • during polymerisation, alkenes undergo an addition reaction • all the atoms in the original alkenes are used to form the polymer • long hydrocarbon chains are formed • the equation shows… the original monomer and the repeating unit in the polymer ethene poly(ethene) MONOMER POLYMER

POLYMERISATION • during polymerisation, alkenes undergo an addition reaction • all the atoms in the original alkenes are used to form the polymer • long hydrocarbon chains are formed • the equation shows… the original monomer and the repeating unit in the polymer the number of repeating units is the same as the number of original molecules n represents a large number ethene poly(ethene) MONOMER POLYMER

The animation shows the monomers turning into the polymer POLYMERISATION The animation shows the monomers turning into the polymer

ALCOHOLS

ALCOHOLS WHAT ARE THEY? ● NOT HYDROCARBONS ● CONTAIN THE –OH FUNCTIONAL GROUP

ALCOHOLS WHAT ARE THEY? ● NOT HYDROCARBONS ● CONTAIN THE –OH FUNCTIONAL GROUP ● EXAMPLES… METHANOL CH3OH ETHANOL C2H5OH PROPANOL C3H7OH GENERAL FORMULA IS… CnH2n+1OH

H C O H H C C O H H C C C O H ALCOHOL STRUCTURES H H H METHANOL ETHANOL CH3OH C2H5OH H H H H C C C O H PROPANOL C3H7OH

H C C C O H STRUCTURAL ISOMERS OF PROPANOL H H H PROPANOL There is another alcohol with the same molecular formula What is it? PROPANOL C3H7OH or CH3CH2CH2OH

H C C C O H H C C C H H O H H STRUCTURAL ISOMERS OF PROPANOL H H H There is another alcohol with the same molecular formula What is it? PROPAN-1-OL C3H7OH or CH3CH2CH2OH H H H H C C C H H O H H PROPAN-2-OL C3H7OH or CH3CH(OH)CH3

REACTIONS OF ALCOHOLS COMBUSTION ALCOHOLS MAKE USEFUL FUELS ETHANOL IS A CLEAN FUEL - DOESN’T FORM POLLUTANTS ETHANOL CAN BE MADE BY FERMENTATION (RENEWABLE) C2H5OH + 3O2 2CO2 + 3H2O ETHANOL OXYGEN CARBON WATER DIOXIDE

REACTIONS OF ALCOHOLS OXIDATION ALCOHOLS CAN BE OXIDISED TO CARBOXYLIC ACIDS ETHANOL IS OXIDISED TO ETHANOIC ACID (ACETIC ACID) THIS IS WHY WINE GOES SOUR WHEN LEFT TOO LONG Air ETHANOL ETHANOIC ACID Wine Vinegar

REACTIONS OF ALCOHOLS ESTERIFICATION ALCOHOLS REACT WITH CARBOXYLIC ACIDS THE REACTION IS REVERSIBLE COMPOUNDS CALLED ESTERS ARE FORMED ESTERS HAVE CHARACTERISTIC SMELLS CH3COOH + C2H5OH CH3COOC2H5 + H2O ETHANOIC ETHANOL ETHYL WATER ACID ETHANOATE

REACTIONS OF ALCOHOLS REACTION WITH SODIUM ALCOHOLS REACT WITH SODIUM HYDROGEN GAS IS PRODUCED 2Na + 2C2H5OH 2C2H5ONa + H2 SODIUM ETHANOL SODIUM HYDROGEN ETHOXIDE

INDUSTRIAL PREPARATION OF ALCOHOLS

INDUSTRIAL PREPARATION OF ALCOHOLS 1. FERMENTATION Reagent(s) GLUCOSE - produced by the hydrolysis of starch Conditions yeast warm, but no higher than 37°C Equation C6H12O6 ——> 2 C2H5OH + 2 CO2 SUGAR ETHANOL CARBON (GLUCOSE) DIOXIDE

INDUSTRIAL PREPARATION OF ALCOHOLS 1. FERMENTATION Reagent(s) GLUCOSE - produced by the hydrolysis of starch Conditions yeast warm, but no higher than 37°C Equation C6H12O6 ——> 2 C2H5OH + 2 CO2 Advantages LOW ENERGY PROCESS USES RENEWABLE RESOURCES - PLANT MATERIAL SIMPLE EQUIPMENT Disadvantages SLOW PRODUCES IMPURE ETHANOL BATCH PROCESS

INDUSTRIAL PREPARATION OF ALCOHOLS 2. HYDRATION OF ETHENE Reagent(s) ETHENE - from cracking of fractions from crude oil Conditions catalyst - phosphoric acid high temperature and pressure Equation C2H4 + H2O ——> 2 C2H5OH ETHENE STEAM ETHANOL

INDUSTRIAL PREPARATION OF ALCOHOLS 2. HYDRATION OF ETHENE Reagent(s) ETHENE - from cracking of fractions from crude oil Conditions catalyst - phosphoric acid high temperature and pressure Equation C2H4 + H2O ——> 2 C2H5OH Advantages FAST PURE ETHANOL PRODUCED CONTINUOUS PROCESS Disadvantages HIGH ENERGY PROCESS EXPENSIVE PLANT REQUIRED USES NON-RENEWABLE FOSSIL FUELS TO MAKE ETHENE

INDUSTRIAL PREPARATION OF ALCOHOLS USES OF ETHANOL ALCOHOLIC DRINKS SOLVENT - industrial alcohol / methylated spirits FUEL - petrol substitute in countries with limited oil reserves

CARBOXYLIC ACIDS

CARBOXYLIC ACIDS WHAT ARE THEY? ● NOT HYDROCARBONS ● CONTAIN THE –COOH FUNCTIONAL GROUP

CARBOXYLIC ACIDS WHAT ARE THEY? ● NOT HYDROCARBONS ● CONTAIN THE –COOH FUNCTIONAL GROUP ● EXAMPLES… METHANOIC ACID HCOOH ETHANOIC ACID CH3COOH PROPANOIC ACID C2H5COOH

CARBOXYLIC ACID STRUCTURES H C O H H O H C C O H H METHANOIC ACID ETHANOIC ACID HCOOH CH3COOH

CARBOXYLIC ACIDS USES ● VINEGAR CONTAINS ETHANOIC ACID - ethanoic acid is used in the manufacture of rayon ● ORANGES AND LEMONS CONTAIN CITRIC ACID ● ASPIRIN IS A CARBOXYLIC ACID - it is used for pain relief and prevention heart attacks ● VITAMIN C CONTAINS ASCORBIC ACID

CARBOXYLIC ACIDS REACTIONS ● WEAK ACIDS - neutralised by alkalis to form salts - react with carbonates making salts, carbon dioxide and water ● REACT WITH ALCOHOLS TO PRODUCE ESTERS

ESTERS

ESTERS WHAT ARE THEY? ● NOT HYDROCARBONS ● CONTAIN THE –COOC FUNCTIONAL GROUP

ESTERS WHAT ARE THEY? ● NOT HYDROCARBONS ● CONTAIN THE –COOC FUNCTIONAL GROUP ● FORMATION… Formed by replacing the H on the COOH of a carboxylic acid by a carbon atom group METHANOIC (HCOOH) METHYL (HCOOCH3) ACID METHANOATE ETHANOIC (CH3COOH) METHYL (CH3COOCH3) ACID ETHANOATE

ESTERS WHAT ARE THEY? ● NOT HYDROCARBONS ● CONTAIN THE –COOC FUNCTIONAL GROUP ● FORMATION… Formed by replacing the H on the COOH of a carboxylic acid by a carbon atom group METHANOIC (HCOOH) METHYL (HCOOCH3) ACID METHANOATE ETHANOIC (CH3COOH) METHYL (CH3COOCH3) ACID ETHANOATE ● USE… Flavourings – many have fruity odours

QUESTIONS

WHICH FORMULAE REPRESENT ALKANES? QUESTIONS WHICH FORMULAE REPRESENT ALKANES? C10H22 C3H6 C2H6 C2H6O C6H12O6 C3H7COOH

WHICH FORMULAE REPRESENT ALKANES? QUESTIONS WHICH FORMULAE REPRESENT ALKANES? C10H22 C3H6 C2H6 C2H6O C6H12O6 C3H7COOH

CARBOXYLIC ACID OR ESTER? QUESTIONS CARBOXYLIC ACID OR ESTER? HCOOC2H5 C3H7COOH C6H6COOCH3 C2H5COOC3H7 CH3COOH

CARBOXYLIC ACID OR ESTER? QUESTIONS CARBOXYLIC ACID OR ESTER? HCOOC2H5 ESTER C3H7COOH CARBOXYLIC ACID C6H6COOCH3 ESTER C2H5COOC3H7 ESTER CH3COOH CARBOXYLIC ACID

WHAT TYPES OF ORGANIC COMPOUND ARE THESE? QUESTIONS WHAT TYPES OF ORGANIC COMPOUND ARE THESE? H H H H – C – C – C – H H H O H C C C O H H H H H H C C H H O H H H O H H C C C O C H H H H

WHAT TYPES OF ORGANIC COMPOUND ARE THESE? QUESTIONS WHAT TYPES OF ORGANIC COMPOUND ARE THESE? H H H H – C – C – C – H H H O H C C C O H H H CARBOXYLIC ACID ALKANE H H H C C H H O H H H O H H C C C O C H H H H ALCOHOL ESTER

©2011 JONATHAN HOPTON & KNOCKHARDY PUBLISHING ORGANIC CHEMISTRY THE END ©2011 JONATHAN HOPTON & KNOCKHARDY PUBLISHING