Transcript gorgpps.pps - Knockhardy

ORGANIC
CHEMISTRY
A guide for GCSE students
2010
KNOCKHARDY PUBLISHING
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
• What is organic chemistry?
• Hydrocarbons
• Alkanes
• Alkenes
• Alcohols
• Industrial preparation of alcohols
• Carboxylic acids and esters
• Questions
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
CnH2n+2
CH4
C 2H 6
HOMOLOGOUS SERIES
A FAMILY OF COMPOUNDS WHICH HAVE…
● A GENERAL FORMULA
● SIMILAR CHEMICAL PROPERTIES
Examples:ALKANES
CnH2n+2
CH4
C 2H 6
ALKENES
CnH2n
C2H4
C 3H 6
HOMOLOGOUS SERIES
WHAT ARE THE NEXT IN EACH SERIES?
ALKANES
ALKENES
CH4
C2H6
C2H4
?
C3H6
?
?
?
?
HOMOLOGOUS SERIES
WHAT ARE THE NEXT IN EACH SERIES?
ALKANES
ALKENES
CH4
C2H6
C2H4
C3H8
C3H6
C4H10
C4H8
C5H12
C5H10
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
C 2H 6
PROPANE
C 3H 8
BUTANE
C4H10
GENERAL FORMULA IS…
CnH2n+2
ALKANE STRUCTURES
H
H–C–H
H
METHANE
CH4
ETHANE
C2H6
PROPANE
C3H8
ALKANE STRUCTURES
H
H–C–H
H
METHANE
CH4
H
H
H–C–C–H
H
H
ETHANE
C2H6
PROPANE
C3H8
ALKANE STRUCTURES
H
H
H–C–H
H
H–C–C–H
H
METHANE
CH4
H
H
ETHANE
C2H6
H
H
H
H–C–C–C–H
H
H
H
PROPANE
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
H–C–H
H–C–C–H
H
H
METHANE
CH4
H
H
H
H
BUTANE
H
H
ETHANE
C2H6
H
H–C–C–C–C–H
H
H
H
C4H10
H
H
H
H–C–C–C–H
H
H
H
PROPANE
C3H8
ALKANE STRUCTURES
H
H
H–C–H
H
METHANE
CH4
H
H
H
BUTANE
H
H
H
H
C4H10
H
H
H–C–C–C–H
H
ETHANE
C2H6
H–C–C–C–C–H
H
H
H–C–C–H
H
H
H
H
H
PROPANE
C3H8
HOWEVER
By the time you get to butane,
there are two ways to arrange the
carbon and hydrogen atoms…
ALKANE STRUCTURES
C4H10
H
H–C–H
H
H
H
H
H–C–C–C–C–H
H
H
H
BUTANE
H
H
H
H – C ––– C ––– C – H
H
H
H
METHYLPROPANE
STRUCTURAL ISOMERS
Compounds with the SAME MOLECULAR FORMULA
but DIFFERENT STRUCTURAL FORMULA
ALKANE STRUCTURES
BEWARE!
THESE ARE ALL
THE SAME
STRUCTURE
H
H
H
H
H
C
C
C
C
H
H
H
H
H
H C H H
H
C
C
HH C H
H
H
H
H
H
H
C
C
C
H
H H C H
H
H
H
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
H
C
C
C
C
C
H
H
H
H
H
C5H12
H
THERE ARE
3 ISOMERS
ISOMERS OF PENTANE
H
H
H
H
H
H
H
C
C
C
C
C
H
H
H
H
H
H
H
H
H
C
C
C
C
H
H
H
H C H
H
H
C5H12
H
THERE ARE
3 ISOMERS
ISOMERS OF PENTANE
H
H
H
H
H
H
H
C
C
C
C
C
H
H
H
H
H
H
H
H
H
C
C
C
C
H
H
H
H C H
H
C5H12
THERE ARE
3 ISOMERS
H
H
H C H
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
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
CH4
+
2O2
CO2 + 2H2O
The more carbon atoms they have the more oxygen they need
C3H8
+
5O2
3CO2 + 4H2O
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
C 2H 4
PROPENE
C 3H 6
BUTENE
C 4H 8
GENERAL FORMULA IS…
CnH2n
ALKENE STRUCTURES
DOUBLE COVALENT BOND
H
H
H
H
H
C
C
C
C
C
H
H
H
ETHENE
C2H4
H
PROPENE
C3H6
H
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
ADDITION REACTIONS
BROMINE
C2H4
H
Br
Br
C
C
H
H
ETHENE
+
H
Br2
C2H4Br2
H
Br
Br
C
C
H
H
H
1,2-DIBROMOETHANE
THIS REACTION IS USED AS A TEST FOR UNSATURATION BROMINE WATER IS ‘DECOLOURISED’.
ADDITION REACTIONS
HYDROGEN
C2H4
H
H
H
C
C
H
H
ETHENE
+
H
H2
CATALYST
H
C2H6
H
H
C
C
H
H
ETHANE
VEGETABLE OILS CONTAINING UNSATURATED FATS
ARE HARDENED TO FORM MARGARINE THIS WAY
H
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
CH3OH
ETHANOL
C2H5OH
PROPANOL
C3H7OH
GENERAL FORMULA IS…
CnH2n+1OH
ALCOHOL STRUCTURES
H
H
C
O
H
H
H
METHANOL
CH3OH
H
H
H
C
C
H
H
O
ETHANOL
C2H5OH
H
H
H
C
C
C
H
H
H
O
H
PROPANOL
C3H7OH
H
STRUCTURAL ISOMERS OF PROPANOL
H
H
H
H
C
C
C
H
H
H
There is another alcohol with
the same molecular formula
O
PROPANOL
C3H7OH or CH3CH2CH2OH
H
What is it?
STRUCTURAL ISOMERS OF PROPANOL
H
H
H
H
C
C
C
H
H
H
There is another alcohol with
the same molecular formula
O
H
What is it?
PROPAN-1-OL
C3H7OH or CH3CH2CH2OH
H
PROPAN-2-OL
C3H7OH or CH3CH(OH)CH3
H
H
H
C
C
C
H
O
H
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)
C2H5OH
ETHANOL
+
3O2
OXYGEN
2CO2 +
CARBON
DIOXIDE
3H2O
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
Air
ETHANOL
Wine
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
CH3COOH + C2H5OH
ETHANOIC
ACID
ETHANOL
CH3COOC2H5 + H2O
ETHYL
ETHANOATE
WATER
REACTIONS OF ALCOHOLS
REACTION WITH SODIUM
• ALCOHOLS REACT WITH SODIUM
• HYDROGEN GAS IS PRODUCED
2Na
SODIUM
+
2C2H5OH
2C2H5ONa
ETHANOL
SODIUM
ETHOXIDE
+
H2
HYDROGEN
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
SUGAR
(GLUCOSE)
——>
2 C2H5OH
ETHANOL
+
2 CO2
CARBON
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
Advantages
LOW ENERGY PROCESS
USES RENEWABLE RESOURCES - PLANT MATERIAL
SIMPLE EQUIPMENT
——>
2 C2H5OH
Disadvantages SLOW
PRODUCES IMPURE ETHANOL
BATCH PROCESS
+
2 CO2
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 +
ETHENE
H2O
STEAM
——>
2 C2H5OH
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 +
Advantages
FAST
PURE ETHANOL PRODUCED
CONTINUOUS PROCESS
H2O
——>
2 C2H5OH
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
• FUEL
- industrial alcohol / methylated spirits
- 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
O
H
C
O
H
H
H
O
C
C
O
H
METHANOIC ACID
HCOOH
ETHANOIC ACID
CH3COOH
H
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 (HCOOH)
ACID
METHYL
METHANOATE
(HCOOCH3)
ETHANOIC (CH3COOH)
ACID
METHYL
ETHANOATE
(CH3COOCH3)
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
METHYL
METHANOATE
(HCOOCH3)
ETHANOIC (CH3COOH)
ACID
METHYL
ETHANOATE
(CH3COOCH3)
● USE…
Flavourings – many have fruity odours
QUESTIONS
QUESTIONS
WHICH FORMULAE REPRESENT ALKANES?
C10H22
C 3H 6
C 2H 6
C 2H 6O
C6H12O6
C3H7COOH
QUESTIONS
WHICH FORMULAE REPRESENT ALKANES?
C10H22
C 3H 6
C 2H 6
C 2H 6O
C6H12O6
C3H7COOH
QUESTIONS
CARBOXYLIC ACID OR ESTER?
HCOOC2H5
C3H7COOH
C6H6COOCH3
C2H5COOC3H7
CH3COOH
QUESTIONS
CARBOXYLIC ACID OR ESTER?
HCOOC2H5
ESTER
C3H7COOH
CARBOXYLIC ACID
C6H6COOCH3
ESTER
C2H5COOC3H7
ESTER
CH3COOH
CARBOXYLIC ACID
QUESTIONS
WHAT TYPES OF ORGANIC COMPOUND ARE THESE?
H
H
H–C–C–C–H
H
H
H
H
H
O
C
C
C
H
H
H
H
O
H
H
H
H
C
C
H
H
O
H
H
H
H
O
C
C
C
H
H
H
O
C
H
H
QUESTIONS
WHAT TYPES OF ORGANIC COMPOUND ARE THESE?
H
H
H–C–C–C–H
H
H
H
O
C
C
C
H
H
H
O
H
H
ALKANE
H
H
H
H
H
C
C
H
H
O
H
ALCOHOL
H
CARBOXYLIC
ACID
H
H
O
C
C
C
H
H
H
O
C
H
ESTER
H
ORGANIC
CHEMISTRY
THE END
©2011 JONATHAN HOPTON & KNOCKHARDY PUBLISHING