organic chemistry a guide for gcse students knockhardy publishing 2010 specifications

ORGANIC ORGANIC CHEMISTRYCHEMISTRYA guide for GCSE studentsA guide for GCSE students

KNOCKHARDY PUBLISHINGKNOCKHARDY PUBLISHING2010 2010

SPECIFICATIONSSPECIFICATIONS

ORGANIC CHEMISTRYORGANIC 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.

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.

CONTENTSCONTENTS

• What is organic chemistry?

• Hydrocarbons

• Alkanes

• Alkenes

• Alcohols

• Industrial preparation of alcohols

• Carboxylic acids and esters

• Questions


This Powerpoint presentation does not cover…

DISTILLATION OF CRUDE OILDISTILLATION OF CRUDE OIL

THE PETROCHEMICAL INDUSTRYTHE PETROCHEMICAL INDUSTRY

POLYMERSPOLYMERS

For further information on these topics, please see the other Powerpoints on the Knockhardy GCSE site.



WHAT IS IT?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 CHAINSBRANCHED CHAINS

and RINGS






• CARBON ATOMS CAN BE ARRANGED IN STRAIGHT CHAINSBRANCHED CHAINS

and RINGS

• OTHER ATOMS/GROUPS OF ATOMS ARE PLACED ON CARBON ATOMS



CARBON ATOMS CAN BE ARRANGED IN

STRAIGHT CHAINS

BRANCHED CHAINS

and RINGS

You can also get a combination of rings and chains


CHAINS AND RINGSCHAINS AND RINGS

CARBON-CARBON COVALENT BONDS CAN BE SINGLE, DOUBLE OR TRIPLE


SINGLE AND MULTIPLE BONDINGSINGLE AND MULTIPLE BONDING

HYDROCARBONSHYDROCARBONS

Compounds containing only Compounds containing only carbon and hydrogen atomscarbon and hydrogen atoms

HOMOLOGOUS SERIESHOMOLOGOUS SERIES

A FAMILY OF COMPOUNDS WHICH HAVE…

● A GENERAL FORMULA

● SIMILAR CHEMICAL PROPERTIES





Examples:-





Examples:-

ALKANES CnH2n+2 CH4 C2H6





Examples:-

ALKANES CnH2n+2 CH4 C2H6

ALKENES CnH2n C2H4 C3H6


WHAT ARE THE NEXT IN EACH SERIES?

ALKANES ALKENES

CH4

C2H6 C2H4

? C3H6

? ?

? ?


WHAT ARE THE NEXT IN EACH SERIES?

ALKANES ALKENES

CH4

C2H6 C2H4

C3H8 C3H6

C4H10 C4H8

C5H12 C5H10

ALKANESALKANES

SATURATED SATURATED HYDROCARBONSHYDROCARBONS

ALKANESALKANES

WHAT ARE THEY?WHAT ARE THEY?

● HYDROCARBONS

● CARBON ATOMS ARE JOINED BY SINGLE COVALENT BONDS

● CONTAIN THE MAXIMUM NUMBER OF HYDROGEN ATOMS

● ARE SATURATED HYDROCARBONS

ALKANESALKANES


● 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 STRUCTURESALKANE STRUCTURES

METHANE ETHANE PROPANE CH4 C2H6 C3H8

H

H – C – H

H



H H

H – C – C – H

H H

H

H – C – H

H



H H

H – C – C – H

H H

H

H – C – H

H

H H H

H – C – C – C – H

H H H

THESE ARE DISPLAYED STRUCTURES

THEY SHOW ALL THECOVALENT BONDS IN THE MOLECULE

Each covalent bond is represented by a line

THESE ARE DISPLAYED STRUCTURES

THEY SHOW ALL THECOVALENT BONDS IN THE MOLECULE

Each covalent bond is represented by a line



H H

H – C – C – H

H H

H

H – C – H

H

H H H

H – C – C – C – H

H H H

H H H H

H – C – C – C – C – H

H H H H

BUTANE C4H10



H H

H – C – C – H

H H

H

H – C – H

H

H H H

H – C – C – C – H

H H H

H H H H

H – C – C – C – C – H

H H H H

BUTANE C4H10

HOWEVERBy the time you get to butane,

there are two ways to arrange the carbon and hydrogen atoms…

HOWEVERBy the time you get to butane,

there are two ways to arrange the carbon and hydrogen atoms…


H H H H

H – C – C – C – C – H

H H H H

BUTANE

H

H – C – H

H H

H – C ––– C ––– C – H

H H H

METHYLPROPANE

C4H10

STRUCTURAL ISOMERSCompounds with the SAME MOLECULAR FORMULA

but DIFFERENT STRUCTURAL FORMULA


H H H

H C C C H

H H H C H

H

H

H C H H

H C C H

H H C H

H

H H H H

H C C C C H

H H H H

BEWARE!THESE ARE ALL

THE SAME STRUCTURE

BEWARE!THESE ARE ALL

THE SAME STRUCTURE

ISOMERS OF PENTANEISOMERS OF PENTANE

C5H12

HOW MANY ISOMERS ARE THERE?

C5H12

HOW MANY ISOMERS ARE THERE?


C5H12

THERE ARE 3 ISOMERS

C5H12

THERE ARE 3 ISOMERS


H H H H H

H C C C C C H

H H H H H

C5H12

THERE ARE 3 ISOMERS

C5H12

THERE ARE 3 ISOMERS


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 C H

H H H H C H

H

C5H12

THERE ARE 3 ISOMERS

C5H12

THERE ARE 3 ISOMERS


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 C H

H H H H C H

H

H H

H C C C H

H HH C H

H

H

H C H

C5H12

THERE ARE 3 ISOMERS

C5H12

THERE ARE 3 ISOMERS

SOME PROPERTIES OF ALKANESSOME 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)



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



CH4 (-161°C) C2H6 (-88°C) C3H8 (-42°C) C4H10 (-0.5°C)



Use as fuels Alkanes make useful fuels


CH4 + 2O2 CO2 + 2H2O


CH4 (-161°C) C2H6 (-88°C) C3H8 (-42°C) C4H10 (-0.5°C)



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

ALKENESALKENES

UNSATURATED UNSATURATED HYDROCARBONSHYDROCARBONS

ALKENESALKENES


● HYDROCARBONS

● CONTAIN A DOUBLE C=C COVALENT BOND

● ARE UNSATURATED HYDROCARBONS – THEY CAN HAVE ATOMS ADDED TO THEM

● ARE MORE REACTIVE THAN ALKANES

ALKENESALKENES


● 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

ALKENE STRUCTURESALKENE STRUCTURES

DOUBLE COVALENT BOND

ETHENE PROPENE C2H4 C3H6

H H

C C

H H

H H H

C C C H

H H

ALKANES & ALKENESALKANES & ALKENES

HOW CAN YOU TELL THEM APART?HOW CAN YOU TELL THEM APART?

ADD BROMINE WATER; if the reddish-brown colour is removed the substance possesses a C=C bond.

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

A B C

ADDITION REACTIONSADDITION REACTIONS

ETHENE 1,2-DIBROMOETHANE

Br Br

H C C H

H H

Br Br

H C C H

H H

C2H4 + Br2 C2H4Br2

THIS REACTION IS USED AS A TEST FOR UNSATURATION - BROMINE WATER IS ‘DECOLOURISED’.

BROMINEBROMINE

ADDITION REACTIONSADDITION REACTIONS

ETHENE ETHANE

H H

H C C H

H H

H H

H C C H

H H

C2H4 + H2 C2H6

CATALYST

VEGETABLE OILS CONTAINING UNSATURATED FATS ARE HARDENED TO FORM MARGARINE THIS WAY

HYDROGENHYDROGEN

POLYMERISATIONPOLYMERISATION

For more detailed information on POLYMERS, please see the appropriate

Powerpoint on the Knockhardy GCSE site.

www.knockhardy.org.uk/gcse.htm

For more detailed information on POLYMERS, please see the appropriate

Powerpoint on the Knockhardy GCSE site.

www.knockhardy.org.uk/gcse.htm

• 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




• the equation shows… the original monomer and the repeating unit in the polymer


ethene poly(ethene)

MONOMER POLYMER

n represents a large number

the number of repeating units is the same as the number of original molecules

The animation shows the monomers turning into the polymer


ALCOHOLSALCOHOLS

ALCOHOLSALCOHOLS


● NOT HYDROCARBONS

● CONTAIN THE –OH FUNCTIONAL GROUP

ALCOHOLSALCOHOLS



● CONTAIN THE –OH FUNCTIONAL GROUP

● EXAMPLES… METHANOL CH3OH

ETHANOL C2H5OH

PROPANOL C3H7OH

GENERAL FORMULA IS… CnH2n+1OH

ALCOHOL STRUCTURESALCOHOL STRUCTURES

METHANOL ETHANOL CH3OH C2H5OH

H

H C O H

H

H H

H C C O H

H H

H H H

H C C C O H

H H H

PROPANOL C3H7OH

STRUCTURAL ISOMERS OF PROPANOL STRUCTURAL ISOMERS OF PROPANOL

H H H

H C C C O H

H H H

PROPANOLC3H7OH or CH3CH2CH2OH

There is another alcohol with the same molecular formula

What is it?


What is it?

STRUCTURAL ISOMERS OF PROPANOL STRUCTURAL ISOMERS OF PROPANOL

H H H

H C C C O H

H H H

H H H

H C C C H

H O H

H


What is it?


What is it?

PROPAN-2-OLC3H7OH or CH3CH(OH)CH3

PROPAN-1-OLC3H7OH or CH3CH2CH2OH

REACTIONS OF ALCOHOLSREACTIONS OF ALCOHOLS

C2H5OH + 3O2 2CO2 + 3H2O

ETHANOL OXYGEN CARBON WATER DIOXIDE

COMBUSTIONCOMBUSTION

• ALCOHOLS MAKE USEFUL FUELS

• ETHANOL IS A CLEAN FUEL - DOESN’T FORM POLLUTANTS

• ETHANOL CAN BE MADE BY FERMENTATION (RENEWABLE)


• 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

OXIDATIONOXIDATION

Air ETHANOL ETHANOIC ACID

Wine Vinegar


CH3COOH + C2H5OH CH3COOC2H5 + H2O

ETHANOIC ETHANOL ETHYL WATER ACID ETHANOATE

ESTERIFICATIONESTERIFICATION

• ALCOHOLS REACT WITH CARBOXYLIC ACIDS

• THE REACTION IS REVERSIBLE

• COMPOUNDS CALLED ESTERS ARE FORMED

• ESTERS HAVE CHARACTERISTIC SMELLS


2Na + 2C2H5OH 2C2H5ONa + H2

SODIUM ETHANOL SODIUM HYDROGEN ETHOXIDE

• ALCOHOLS REACT WITH SODIUM

• HYDROGEN GAS IS PRODUCED

REACTION WITH SODIUMREACTION WITH SODIUM

INDUSTRIAL PREPARATION OF ALCOHOLSINDUSTRIAL PREPARATION OF ALCOHOLS


1. FERMENTATION1. FERMENTATION

Reagent(s) GLUCOSE - produced by the hydrolysis of starch

Conditions yeastwarm, but no higher than 37°C

Equation C6H12O6 ——> 2 C2H5OH + 2 CO2

SUGAR ETHANOL CARBON (GLUCOSE) DIOXIDE


1. FERMENTATION1. FERMENTATION

Reagent(s) GLUCOSE - produced by the hydrolysis of starch

Conditions yeastwarm, but no higher than 37°C

Equation C6H12O6 ——> 2 C2H5OH + 2 CO2

Advantages LOW ENERGY PROCESSUSES RENEWABLE RESOURCES - PLANT MATERIALSIMPLE EQUIPMENT

Disadvantages SLOWPRODUCES IMPURE ETHANOLBATCH PROCESS

2. HYDRATION2. HYDRATION OFOF ETHENEETHENE

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

2. HYDRATION2. HYDRATION OFOF ETHENEETHENE

Reagent(s) ETHENE - from cracking of fractions from crude oil

Conditions catalyst - phosphoric acid high temperature and pressure

Equation C2H4 + H2O ——> 2 C2H5OH

Advantages FASTPURE ETHANOL PRODUCEDCONTINUOUS PROCESS

Disadvantages HIGH ENERGY PROCESSEXPENSIVE PLANT REQUIREDUSES NON-RENEWABLE FOSSIL FUELS TO MAKE ETHENE


USES OF ETHANOLUSES OF ETHANOL

• ALCOHOLIC DRINKS

• SOLVENT - industrial alcohol / methylated spirits

• FUEL - petrol substitute in countries with limited oil reserves


CARBOXYLIC CARBOXYLIC ACIDSACIDS

CARBOXYLIC ACIDSCARBOXYLIC ACIDS



● CONTAIN THE –COOH FUNCTIONAL GROUP




● CONTAIN THE –COOH FUNCTIONAL GROUP

● EXAMPLES… METHANOIC ACID HCOOH

ETHANOIC ACID CH3COOH

PROPANOIC ACID C2H5COOH

CARBOXYLIC ACID STRUCTURESCARBOXYLIC ACID STRUCTURES

METHANOIC ACID ETHANOIC ACID HCOOH CH3COOH

O

H C O H

H O

H C C O H

H


USESUSES

● 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


REACTIONSREACTIONS

● WEAK ACIDS - neutralised by alkalis to form salts - react with carbonates making salts, carbon dioxide and water

● REACT WITH ALCOHOLS TO PRODUCE ESTERS

ESTERSESTERS

ESTERSESTERS



● CONTAIN THE –COOC FUNCTIONAL GROUP

ESTERSESTERS




● 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

ESTERSESTERS




● 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

QUESTIONSQUESTIONS

QUESTIONSQUESTIONS

C10H22 C3H6 C2H6

C2H6O C6H12O6C3H7COOH

WHICH FORMULAE REPRESENT ALKANES?

QUESTIONSQUESTIONS

HCOOC2H5

C3H7COOH

C6H6COOCH3

C2H5COOC3H7

CH3COOH

CARBOXYLIC ACID OR ESTER?

QUESTIONSQUESTIONS

HCOOC2H5 ESTER

C3H7COOH CARBOXYLIC ACID

C6H6COOCH3 ESTER

C2H5COOC3H7 ESTER

CH3COOH CARBOXYLIC ACID

CARBOXYLIC ACID OR ESTER?

QUESTIONSQUESTIONS

WHAT TYPES OF ORGANIC COMPOUND ARE THESE?

H H H

H – C – C – C – H

H H H

H H O

H C C C O H

H H

H H O H

H C C C O C H

H H H

H H

H C C H

H O H

QUESTIONSQUESTIONS

WHAT TYPES OF ORGANIC COMPOUND ARE THESE?

H H H

H – C – C – C – H

H H H

H H O

H C C C O H

H H

H H O H

H C C C O C H

H H H

H H

H C C H

H O H

ALKANECARBOXYLIC

ACID

ALCOHOL ESTER

ORGANIC ORGANIC CHEMISTRYCHEMISTRY

THE ENDTHE END

©©2011 JONATHAN HOPTON & KNOCKHARDY PUBLISHING2011 JONATHAN HOPTON & KNOCKHARDY PUBLISHING

organic chemistry a guide for gcse students knockhardy publishing 2010 specifications

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