ORGANIC CHEMISTRY A guide for GCSE students KNOCKHARDY PUBLISHING SPECIFICATIONS ORGANIC CHEMISTRY INTRODUCTION This Powerpoint show is one of several produced to help students understand selected GCSE Chemistry.
Download ReportTranscript ORGANIC CHEMISTRY A guide for GCSE students KNOCKHARDY PUBLISHING SPECIFICATIONS ORGANIC CHEMISTRY INTRODUCTION This Powerpoint show is one of several produced to help students understand selected GCSE Chemistry.
ORGANIC CHEMISTRY
A guide for GCSE students
2010 SPECIFICATIONS
ORGANIC CHEMISTRY
INTRODUCTION 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
Industrial preparation of alcohols
ORGANIC CHEMISTRY
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 and STRAIGHT CHAINS BRANCHED CHAINS 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 and STRAIGHT CHAINS BRANCHED CHAINS 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 and STRAIGHT CHAINS BRANCHED CHAINS RINGS • OTHER ATOMS/GROUPS OF ATOMS ARE PLACED ON CARBON ATOMS
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
ORGANIC CHEMISTRY SINGLE AND MULTIPLE BONDING CARBON-CARBON COVALENT BONDS CAN BE SINGLE, DOUBLE OR TRIPLE
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 C n H 2n+2 CH 4 C 2 H 6
HOMOLOGOUS SERIES A FAMILY OF COMPOUNDS WHICH HAVE… ● A GENERAL FORMULA ● SIMILAR CHEMICAL PROPERTIES Examples: ALKANES ALKENES C C n n H H 2n+2 2n CH C 2 H 4 4 C 2 H 6 C 3 H 6
HOMOLOGOUS SERIES WHAT ARE THE NEXT IN EACH SERIES?
ALKANES
CH
4
C
2
H
6 ?
? ?
ALKENES
C
2
H
4
C
3
H
6 ?
?
HOMOLOGOUS SERIES WHAT ARE THE NEXT IN EACH SERIES?
ALKANES
CH
4
C
2
H
6 C 3 H 8 C 4 H 10 C 5 H 12 ALKENES
C C
C C 2 3 4 5
H H
H H 4 6 8 10
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 ETHANE PROPANE BUTANE GENERAL FORMULA IS… CH 4 C 2 H 6 C 3 H 8 C 4 H 10 C n H 2n+2
H H – C – H H METHANE CH 4 ALKANE STRUCTURES ETHANE C 2 H 6 PROPANE C 3 H 8
H H – C – H H METHANE CH 4 ALKANE STRUCTURES H H H – C – C – H H H ETHANE C 2 H 6 PROPANE C 3 H 8
H H – C – H H METHANE CH 4 ALKANE STRUCTURES H H H – C – C – H H H ETHANE C 2 H 6 H H H H – C – C – C – H H H H PROPANE C 3 H 8 THESE ARE DISPLAYED STRUCTURES THEY SHOW ALL THE COVALENT BONDS IN THE MOLECULE Each covalent bond is represented by a line
H H – C – H H METHANE CH 4 ALKANE STRUCTURES H H H – C – C – H H H ETHANE C 2 H 6 H H H H – C – C – C – H H H H PROPANE C 3 H 8 H H H H H – C – C – C – C – H H H H H BUTANE C 4 H 10
H H – C – H H METHANE CH 4 ALKANE STRUCTURES H H H – C – C – H H H ETHANE C 2 H 6 H H H H – C – C – C – H H H H PROPANE C 3 H 8 H H H H H – C – C – C – C – H H H H H BUTANE C 4 H 10 HOWEVER By the time you get to butane, there are two ways to arrange the carbon and hydrogen atoms …
ALKANE STRUCTURES H H H H H – C – C – C – C – H H H H H BUTANE C 4 H 10 H H
–
C – H H H H – C ––– C ––– C – H H H H METHYLPROPANE STRUCTURAL ISOMERS Compounds with the SAME MOLECULAR FORMULA but DIFFERENT STRUCTURAL FORMULA
BEWARE!
THESE ARE ALL THE SAME STRUCTURE ALKANE STRUCTURES
H H H H H C C C C H H H H H H H H C H H C C H H C H H H H H H H C C C H H H C H H H
ISOMERS OF PENTANE
C
5
H
12
HOW MANY ISOMERS ARE THERE?
ISOMERS OF PENTANE C 5 H 12 THERE ARE 3 ISOMERS
ISOMERS OF PENTANE H H H H H H C C C C C H H H H H H C 5 H 12 THERE ARE 3 ISOMERS
ISOMERS OF PENTANE H H H H H H C C C C C H H H H H H C 5 H 12 THERE ARE 3 ISOMERS H H H H H C C C C H H H C H H H H
ISOMERS OF PENTANE H H H H H H C C C C C H H H H H H H H H H H C C C H H H C H C H H H C 5 H 12 THERE ARE 3 ISOMERS H H C H H H H C C C H H H C H H H
SOME PROPERTIES OF ALKANES
SOME PROPERTIES OF ALKANES Boiling point increases as they get more carbon atoms in the formula CH 4 (-161 °C) C 2 H 6 (-88 °C) C 3 H 8 (-42 °C) C 4 H 10 (-0.5
°C)
SOME PROPERTIES OF ALKANES Boiling point increases as they get more carbon atoms in the formula CH 4 (-161 °C) C 2 H 6 (-88 °C) C 3 H 8 (-42 °C) C 4 H 10 (-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 CH 4 (-161 °C) C 2 H 6 (-88 °C) C 3 H 8 (-42 °C) C 4 H 10 (-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 CH 4 + 2O 2 CO 2 + 2H 2 O
SOME PROPERTIES OF ALKANES Boiling point increases as they get more carbon atoms in the formula CH 4 (-161 °C) C 2 H 6 (-88 °C) C 3 H 8 (-42 °C) C 4 H 10 (-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 CH 4 + 2O 2 CO 2 + 2H 2 O The more carbon atoms they have the more oxygen they need C 3 H 8 + 5O 2 3CO 2 + 4H 2 O
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 PROPENE BUTENE GENERAL FORMULA IS… C C 2 n H C 3 H 6 C 4 H 8 H 4 2n
H H C C H H
ETHENE C 2 H 4 ALKENE STRUCTURES DOUBLE COVALENT BOND
H H H C C C H H H
PROPENE C 3 H 6
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 PLACE A SOLUTION OF BROMINE IN A TEST TUBE B ADD THE HYDROCARBON TO BE TESTED AND SHAKE C IF THE BROWN COLOUR DISAPPEARS THEN THE HYDROCARBON IS AN ALKENE A B C
C
2
H
4 ADDITION REACTIONS BROMINE
+ Br
2
C
2
H
4
Br
2
Br Br H C C H H H
ETHENE
Br Br H C C H H H
1,2-DIBROMOETHANE THIS REACTION IS USED AS A TEST FOR UNSATURATION BROMINE WATER IS ‘DECOLOURISED’.
C
2
H
4 ADDITION REACTIONS HYDROGEN
+ H
2 CATALYST
C
2
H
6
H H H C C H H H
ETHENE
H H H C C H H H
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
MONOMER
poly(ethene)
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 n represents a large number
ethene
MONOMER
poly(ethene)
POLYMER the number of repeating units is the same as the number of original molecules
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 ETHANOL PROPANOL GENERAL FORMULA IS… CH 3 OH C 2 H 5 OH C 3 H 7 OH C n H 2n+1 OH
ALCOHOL STRUCTURES
H H C O H H
METHANOL CH 3 OH
H H H C C H H H C O H H H H H C C O H H H
ETHANOL C 2 H 5 OH PROPANOL C 3 H 7 OH
STRUCTURAL ISOMERS OF PROPANOL
H H H C C H C O H H H H
PROPANOL C 3 H 7 OH or CH 3 CH 2 CH 2 OH There is another alcohol with the same molecular formula What is it?
STRUCTURAL ISOMERS OF PROPANOL
H H H C C H C O H H H H
PROPAN-1-OL C 3 H 7 OH or CH 3 CH 2 CH 2 OH There is another alcohol with the same molecular formula What is it?
H H H C C H C H
PROPAN-2-OL C 3 H 7 OH or CH 3 CH(OH)CH 3
H O H H
REACTIONS OF ALCOHOLS COMBUSTION
•
ALCOHOLS MAKE USEFUL FUELS
• •
ETHANOL IS A CLEAN FUEL DOESN’T FORM POLLUTANTS ETHANOL CAN BE MADE BY FERMENTATION (RENEWABLE) C 2 H 5 OH + 3O 2 ETHANOL OXYGEN 2CO 2 CARBON DIOXIDE + 3H 2 O WATER
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 ETHANOL Wine Air ETHANOIC ACID Vinegar
REACTIONS OF ALCOHOLS ESTERIFICATION
•
ALCOHOLS REACT WITH CARBOXYLIC ACIDS
•
THE REACTION IS REVERSIBLE
•
COMPOUNDS CALLED ESTERS ARE FORMED
•
ESTERS HAVE CHARACTERISTIC SMELLS CH 3 COOH + C 2 H 5 OH ETHANOIC ETHANOL ACID CH 3 COOC 2 H 5 ETHYL ETHANOATE + H 2 O WATER
REACTIONS OF ALCOHOLS REACTION WITH SODIUM
•
ALCOHOLS REACT WITH SODIUM
•
HYDROGEN GAS IS PRODUCED 2Na + 2C 2 H 5 OH SODIUM ETHANOL 2C 2 H 5 ONa + H 2 SODIUM ETHOXIDE HYDROGEN
INDUSTRIAL PREPARATION OF ALCOHOLS
INDUSTRIAL PREPARATION OF ALCOHOLS 1. FERMENTATION Reagent(s) GLUCOSE - produced by the hydrolysis of starch Conditions Equation yeast warm, but no higher than 37 °C C 6 H 12 O 6 SUGAR (GLUCOSE) ——> 2 C 2 H 5 OH + 2 CO 2 ETHANOL CARBON DIOXIDE
INDUSTRIAL PREPARATION OF ALCOHOLS 1. FERMENTATION Reagent(s) GLUCOSE - produced by the hydrolysis of starch Conditions Equation yeast warm, but no higher than 37 °C C 6 H 12 O 6 ——> 2 C 2 H 5 OH + 2 CO 2 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 Equation catalyst - phosphoric acid high temperature and pressure C 2 H 4 ETHENE + H 2 O ——> 2 C 2 H 5 OH STEAM ETHANOL
INDUSTRIAL PREPARATION OF ALCOHOLS 2. HYDRATION OF ETHENE Reagent(s) ETHENE - from cracking of fractions from crude oil Conditions Equation catalyst - phosphoric acid high temperature and pressure C 2 H 4 + H 2 O ——> 2 C 2 H 5 OH 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 ETHANOIC ACID PROPANOIC ACID HCOOH CH 3 COOH C 2 H 5 COOH
CARBOXYLIC ACID STRUCTURES
O H C O H
METHANOIC ACID HCOOH
H O H C C O H H
ETHANOIC ACID CH 3 COOH
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 - it is used for pain relief and prevention heart attacks
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 (HCOO H ) ACID ETHANOIC (CH 3 COO H ) ACID METHYL METHAN OATE (HCOO CH 3 ) METHYL (CH 3 COO CH 3 ) ETHAN OATE
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) ACID ETHANOIC (CH 3 COOH) ACID METHYL METHANOATE (HCOOCH 3 ) METHYL (CH 3 COOCH 3 ) ETHANOATE ● USE… Flavourings – many have fruity odours
QUESTIONS
QUESTIONS WHICH FORMULAE REPRESENT ALKANES?
C 10 H 22 C 2 H 6 O C C 3 6 H H 6 12 O 6 C C 2 3 H H 6 7 COOH
QUESTIONS WHICH FORMULAE REPRESENT ALKANES?
C 10 H 22 C 2 H 6 O C C 3 6 H H 6 12 O 6 C C 2 3 H H 6 7 COOH
QUESTIONS CARBOXYLIC ACID OR ESTER?
HCOOC 2 H 5 C 3 H 7 COOH C 6 H 6 COOCH 3 C 2 H 5 COOC 3 H 7 CH 3 COOH
QUESTIONS CARBOXYLIC ACID OR ESTER?
HCOOC 2 H 5 ESTER C C C 3 6 2 H H H 7 6 5 COOH COOCH COOC CH 3 COOH 3 H 3 7 CARBOXYLIC ACID ESTER ESTER CARBOXYLIC ACID
QUESTIONS WHAT TYPES OF ORGANIC COMPOUND ARE THESE? H H H H – C – C – C – H H H H
H H H C C O C O H H H H H H C C H H O H H H H C C H H O H C O C H H
QUESTIONS WHAT TYPES OF ORGANIC COMPOUND ARE THESE? H H H H – C – C – C – H H H H ALKANE
H H H C C H H O C O H
CARBOXYLIC ACID
H H H C C H H O H
ALCOHOL
H H H C C H H O
ESTER