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Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
ORGANIC CHEMISTRYThe study of compounds containing carbon
except carbonates, the allotropes and oxides of carbon.
ENTER
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
OBJECTIVES
After you have completed the viewing of this tutorial, you will be able to: • Recall that carbon forms branched and unbranched chains and
ring compounds • Illustrate that carbon atoms can form single bonds, double bonds
and triple bonds• List the general characteristics of a homologous series• Write general and molecular formulae for members of a given
homologous series• Write formulae to represent simple organic compounds• Describe the reactions of alkanes and alkenes• Write equations for the reactions of alkanes and alkenes.
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
INTRODUCTION: Carbon is Unique!
1. It has 4 electrons in its outer shell 2. It can bond to 4 other atoms.3. It can form single, double and triple bonds.
C-CSINGLE BOND
C=CDOUBLE BOND
C CTRIPLE BOND
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
CARBON IS UNIQUE!
It can form long chains with other carbon atoms:
C CC C
Straight Branched
Ring
C C
CC
C
C
C CC
C
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
Bonding in Organic Compounds
• Covalent bonds are usually formed in organic compounds.
• Show the bonding present in methane, CH4.
FEEDBACK
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
FEEDBACK
C H
H
H
HX
X
X X
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
CHARACTERISTICS OF HOMOLOGOUS SERIES
Organic compounds are grouped into families called homologous series.• Members can be represented by the same general
molecular formula.• Members display similar chemical properties.• There is a gradual change in physical properties as
the carbon chain increases.• The relative molecular mass increases by 14 as the
carbon chain increases by one.
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
HOMOLOGOUS SERIES
HOMOLOGOUS SERIES GENERAL MOLECULAR FORMULA
Alkanes CnH2n+2
Alkenes CnH2n
Alcohols CnH2n+1OH
Carboxylic Acids (Alkanoic Acids) CnH2n+1COOH
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
NAMING ORGANIC COMPOUNDS
1. Find and name the longest continuous carbon chain.2. Identify and name any group(s) attached to this chain.3. Number the chain consecutively, starting at the end nearer
to a substituent group.4. Indicate the position of each substituent group by an
appropriate number. 5. If there are more than one substituent then list them in
alphabetical order. Note. Use the prefixes di, tri, tetra etc., to designate several groups of the same kind. These prefixes are not considered when putting substituents in alphabetical order.
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
Name the compound.
C
H
C C C C
H H
H
H
H
H H H H H
C
H
HH
CHECK
• Find and name the longest continuous carbon chain.
• Identify and name any group(s) attached to this chain.
• Number the chain consecutively, starting at the end nearer to a substituent group.
• Indicate the position of each substituent group by an appropriate number.
• If there are more than one substituent then list them in alphabetical order. Use the prefixes di, tri, tetra etc., to designate several groups of the same kind. (These prefixes are not considered when putting substituents in alphabetical order.)
X
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
Name the compound.
C
H
C C C C
H H
H
H
H
H H H H H
C
H
HH
• Find and name the longest continuous carbon chain.
• Identify and name any group(s) attached to this chain.
• Number the chain consecutively, starting at the end nearer to a substituent group.
• Indicate the position of each substituent group by an appropriate number.
• If there are more than one substituent then list them in alphabetical order. Use the prefixes di, tri, tetra etc., to designate several groups of the same kind. (These prefixes are not considered when putting substituents in alphabetical order.)
X
Name of compound: 2-methyl pentane
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
Name the compound.
C C C C C
C
• Find and name the longest continuous carbon chain.
• Identify and name any group(s) attached to this chain.
• Number the chain consecutively, starting at the end nearer to a substituent group.
• Indicate the position of each substituent group by an appropriate number.
• If there are more than one substituent then list them in alphabetical order. Use the prefixes di, tri, tetra etc., to designate several groups of the same kind. (These prefixes are not considered when putting substituents in alphabetical order.)
X
C C
C
H H H
H
H
H
H H H
H
H
H
HH
HHH
H
H
H
CHECK
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
Name the compound.
C C C C C
C
• Find and name the longest continuous carbon chain.
• Identify and name any group(s) attached to this chain.
• Number the chain consecutively, starting at the end nearer to a substituent group.
• Indicate the position of each substituent group by an appropriate number.
• If there are more than one substituent then list them in alphabetical order. Use the prefixes di, tri, tetra etc., to designate several groups of the same kind. (These prefixes are not considered when putting substituents in alphabetical order.)
X
CHECK
C C
C
H H H
H
H
H
H H H
H
H
H
HH
HHH
H
H
H
Name of compound: 2, 4-dimethyl heptane
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
ALKANES: Saturated hydrocarbons
General Molecular Formula for Alkanes: CnH2n+2
Molecular Formula
Name Relative Molecular Formula
State at room temperature
CH4 Methane 16 gasC2H6 Ethane 30 gasC3H8 Propane 44 gasC4H10 Butane 58 gasC5H12 Pentane 72 liquidC6H14 Hexane 86 liquidC7H16 Heptane 100 liquidC8H18 Octane 114 liquidC9H20 Nonane 128 liquidC10H22 Decane 142 liquid
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
ALKANES
Draw the structural formula of butane.
FEEDBACK
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
You should realize there are two ways of drawing the structural formula of butane:
ALKANES
H
C
H
C
H
H H
H
C
H H
CH H H C
H
C
H
H H
C
H
H
C HH
H
Continue
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
Both structures have four carbon atoms and ten hydrogen atoms, i.e. they have the same molecular formula but different structural formula. They are called ISOMERS.
ALKANES - Isomers
H
C
H
C
H
H H
H
C
H H
CH H H C
H
C
H
H H
C
H
H
C HH
H
Continue
C CC C C CC
C
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
ISOMERS are compounds with the same molecular formula but different structural formula. Name the compounds below.
ALKANES - Isomers
H
C
H
C
H
H H
H
C
H H
CH H H C
H
C
H
H H
C
H
H
C HH
H
CHECK
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
ISOMERS are compounds with the same molecular formula but different structural formula. Name the compounds below.
ALKANES - Isomers
H
C
H
C
H
H H
H
C
H H
CH H H C
H
C
H
H H
C
H
H
C HH
H
butane methylpropane or 2-methylpropane
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
REACTIONS OF ALKANES
Combustion Halogenation
Cracking
Click on a reaction name to proceed.
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
Reactions of Alkanes: COMBUSTION
When an alkane burns in excess air, carbon dioxide and water are produced.
ALKANE EXCESS OXYGEN CARBON DIOXIDE WATER+ +
Examples:CH4(g) + 2O2 (g) CO2 (g) + 2H2O (g)
2 C2H6 (g) + 7O2 (g) 4 CO2(g) + 6H2O(g)
Combustion Halogenation Cracking
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
Reactions of Alkanes: COMBUSTION
Write balanced equations for the combustion of butane and pentane in excess air.
FEEDBACK
Combustion Halogenation Cracking
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
Reactions of Alkanes: COMBUSTION
Balanced equations for the combustion of butane and pentane in excess air:
2 C4H10(g) + 13O2 (g) 8CO2 (g) + 10H2O (g)
C5H12(g) + 8O2 (g) 5CO2(g) + 6H2O(g)
Butane
Pentane
Combustion Halogenation Cracking
What substances do you think can be produced if an alkane is burnt in a limited supply of air? Check your answers. Ask your teacher.
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
Reactions of Alkanes: HALOGENATION
LIGHT has to be present for Halogenation to take place. The reaction takes place in a series of steps:
SHOW ME
Try and name the products.
CH4 (g) + Cl2 (g) CH3Cl (g) + HCl (g)
CH3Cl (g) + Cl2 (g) CH2Cl2 (g) + HCl (g)
CH2Cl2 (g) + Cl2 (g) CHCl3 (g) + HCl (g)
CHCl3 (g) + Cl2 (g) CCl4 (g) + HCl (g)
Combustion Halogenation Cracking
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
Reactions of Alkanes: CRACKING
Cracking is the process by which long hydrocarbon chains are broken into smaller, more useful hydrocarbons.e.g. C12H26 (l) C7H16 (l) + C5H10 (l)
Note that the number of carbon atoms in the products adds up to the number of carbon atoms in the reactant. The same is true for the hydrogen atoms. Complete the equation of the reaction and name the products. C18H38 C10H22 + ________
FEEDBACK
Combustion Halogenation Cracking
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
FEEDBACK
C18H38 C10H22 + C8H16
decane octene
Combustion Halogenation Cracking
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
ALKENES: Unsaturated Compounds
• Characterized by the presence of a C-C double bond (C=C)• General Molecular Formula: CnH2n
Molecular Formula Name Relative Molecular Formula State at room temperature
C2H4 Ethene 28 gasC3H6 Propene 42 gasC4H8 Butene 56 gasC5H10 Pentene 70 liquidC6H12 Hexene 84 liquidC7H14 Heptene 98 liquidC8H16 Octene 112 liquidC9H18 Nonene 126 liquidC10H20 Decene 140 liquid
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
ALKENES: Isomers
Note there are three isomers of butene:
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
REACTIONS OF ALKENES
Alkenes undergo ADDITION reactions.
Combustion (Burning)
Halogenation(Reaction with a halogen)
Hydrogenation (Reaction with Hydrogen)
Hydration(Reaction with water)
Click on a reaction name to proceed.
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
REACTIONS OF ALKENES: Combustion
Just as with alkanes, when alkenes burn in excess air, carbon dioxide and water are produced.
ALKENE + EXCESS OXYGEN CARBON DIOXIDE + WATER
e.g. C2H4 (g) + 3O2 (g) 2CO2 (g) + 2H2O (g)
2C3H6 (g) + 9O2 (g) 6CO2 (g) + 6H2O (g)
Write balanced equations for the combustion of butene and pentene in excess air.
Combustion (Burning)
Halogenation(Reaction with a halogen)
Hydrogenation (Reaction with Hydrogen)
Hydration(Reaction with water)
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
REACTIONS OF ALKENES: Hydrogenation
Alkenes react with hydrogen in the presence of a nickel catalyst at 150 oC to produce the corresponding alkane.
ethene ethane C2H4 (g) + H2 (g) C2H6 (g)
H
C
H
C
H
H H
H
C
H H
C HHNi
150 oC HH+
Ni150 oC
Combustion (Burning)
Halogenation(Reaction with a halogen)
Hydrogenation (Reaction with Hydrogen)
Hydration(Reaction with water)
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
REACTIONS OF ALKENES: Hydration
Alkenes react with water in the presence of phosphoric acid at 300 oC to produce the corresponding alcohol.
ethene water ethanol C2H4 + H2O C2H5OH
OH
C
H
C
H
H H
H
C
H H
COH HH H
H3PO4
300 oC
+
H3PO4
300 oC Combustion
(Burning)Halogenation
(Reaction with a halogen)Hydrogenation
(Reaction with Hydrogen)Hydration
(Reaction with water)
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
REACTIONS OF ALKENES: Halogenation
Alkenes react readily with halogens, even in the dark.
ethene Bromine 1,2-dibromoethane(red-brown) (colourless)
C2H4 (g) + Br2 (aq) C2H4 Br2 (l) This reaction is used to distinguish between saturated and unsaturated compounds.
Br
C
H
C
H
H H
Br
C
H H
C HBr H+ Br
Combustion (Burning)
Halogenation(Reaction with a halogen)
Hydrogenation (Reaction with Hydrogen)
Hydration(Reaction with water)
Objectives Homologous Series
Naming Compounds Alkanes Reactions of
Alkanes Alkenes Reactions of AlkenesIntroduction
ORGANIC CHEMISTRYx
Assignment
Click on the link below and test yourself on alkanes and alkenes.
http://www.gcsescience.com/q/qhyalk.html