Year 11 Chemistry:~ Chapter 8 Carbon Compounds
8.1 Why is carbon important?
Carbon compounds make up over ___ % of all chemical compounds and many form the
basis of living systems. The study of carbon compounds being known as ‘_________
chemistry’.
In organic compounds carbon is associated with _____________ and commonly
oxygen, nitrogen, sulfur and chlorine.
Proteins, ____________ and fats all contain ________ , hydrogen and _________ .
Proteins are also a source of nitrogen and sulfur. Vitamins and minerals introduce
trace elements that we need in our diets.
8.2 How does carbon form so many compounds?
Carbons subshell electronic configuration is __________ . Carbon forms are wide
variety of compounds because:



Natural gas
It is thought that natural gas and petroleum are formed by the chemical degradation
of organic matter from the remains of land and aquatic plants. Under certain
conditions the materials is converted into many different compounds of ________
and __________ . These are called ______________ . Natural gas is a mixture of
many different compounds (see table 8.1).
8.3 Hydrocarbons
Fossil fuels – coal and oil as well as natural gas – contain a wide range of
hydrocarbons.
Hydrocarbons can be classified into several series or families. In a _____________
series each compound differs by - and has similar properties.
Alkanes – single covalent bond (saturated)
Alkanes consist of only carbon and hydrogen and contain only _________ covalent
bonds between carbons. Each alkane differs by -.
General Molecular
Formula
Example: if there were 16 carbons atoms, what is the molecular formula?
Crude oil contains a variety of hydrocarbons with n having values from 5 to
approximately 70.
*List the first 10 alkanes
Molecular Formula
Name
Representing alkane molecules
Structural formula are very similar to valence structures apart from the lone pairs
being omitted.
*Draw fig 8.5 (pg 137)
Each of these molecules have similarities in their structure:



*Draw the structural formula for butane (C4H10)
Straight chain molecule
branched chain molecule
When there is more than one way to draw the structural formula, they are known as
structural ____________ .
___________ isomers have similar chemical properties but differ in some physical
properties, eg melting temperature and boiling temperature. The alkane C20H42 has
_________ possible isomers. Alkanes are known as saturated because they are
‘saturated with __________ atoms.
Alkenes – double covalent bond (unsaturated)
Unsaturated: ____________________________________________________
________________________________________________________________
A common alkene is ethene which has the molecular formula _____. It is the first
member of the homologous series and contains one carbon-carbon ________ bond.
General Molecular Formula
*List the first 10 alkenes
Molecular Formula
Name
Representing alkene molecules
*Draw structural formula for ethene and propene
Butene has three __________ isomers, two of them are straight chain isomers,
differing only in the position of the ________ bond. The third isomer has a
branched chain.
Straight chain molecule
Branched chain molecule
Semistructural formula
In a semistructural formula the carbon atoms and the attached hydrogen atoms are
listed in order which they appear in the structural formula. Single bonds are not
indicated but any ________ or ________ bonds are shown.
Groups of atoms that form branches in a molecule are written in brackets after the
carbon atom to which they are attached.
*Write semistructural for the above alkenes
Questions:
8.4 Naming carbon compounds
IN the early 1960’s a common naming system was developed and endorse by the
International Union of Pure and Applied Chemistry ( ______ ).
Straight chain Hydrocarbons
The first part of the name refers to how many carbon atoms are in the molecule, the
end depends on if it contains single, double or triple bonds.
 ane  ene  yne No. of carbon atoms
Prefix
1
2
3
4
5
6
7
8
9
10
Unsaturated compounds (contain a covalent double or triple bond)
To name straight alkenes or alkynes, first number the carbon atoms in the chain,
starting at the end that will give the first carbon atom involved in the double or
triple bond the smallest number possible.
*Copy diagrams off whiteboard for the two straight chain isomers of butene.
Branched Hydrocarbons
An alkyl group most often forms a branch in a branched-chain hydrocarbon. An alkyl
group is an alkane molecule less one hydrogen atom and is named after the alkane
from which it is derived. Remove –ane and replace with -yl
 -CH3 is a ______ group.
 C2H5 (-CH2CH3) is an _______ group.
 C3H7 (-CH2CH2CH3) is a ______ group.
*Draw structures of alkyl groups
Systematic naming requires:
 Identify the longest continous chain of carbon atoms.
 Identify the side group that forms the branch in the chain.
 Number the carbon atoms from one of the ends of the longest carbon chain so
that the side group is attached to the carbon atom with the smallest number
possible (if there is a double bond it takes precedant).
*Copy diagrams from whiteboard
Questions:
8.5 Properties of alkanes and alkenes
Define the term volatile: ___________________________________________
________________________________________________________________
Compounds with smaller molecules are more volalite than those with larger molecules.
Less energy is needed to overcome the _________ between the smaller molecules.
eg petrol and oil, which one is more volatile? ______________________________
It is the vapour above the liquid that burns therefore more ___________
compounds will burn more _______ .
Define the term viscosity: __________________________________________
________________________________________________________________
More volatile compounds also have a lower __________. Eg oil has a _______
viscosity and petrol would have a ________ viscosity.
The boiling temperature os a hydrocarbon increases with the number of carbons in
the molecule, see table 8.7.
Alkenes have similar physical properties to alkanes. Boiling temperature and viscosity
___________ with molecule size and volatility __________ with molecule size.
Eg. Propene has a boiling temperature of -48°C and propane is -42°C.
Forces between hydrocarbon molecules (_______molecular)
The bonding between atoms within a hydrocarbon molecules ( _____________ ) is
covalent – one of the forms of strong bonding. The molecules of hydrocarbons are
(polar / non-polar). The forces between hydrocarbon molecules are therefore
____________ forces which increase in strength as the size of the molecules
___________ . Boiling temperatures and volatility relate to the strength of
intermolecular bonding. Eg the stronger the dispersion forces between the molecules
the ________ the boiling temperature and _________ volatility.
The higher the viscosity of the longer-chain hydrocarbons is due to the tendency of
longer molecules to become ‘tangled’ together.
Chemical properties of alkanes
When alkanes burn in oxygen they undergo combustion. If oxygen is in excess then
water and carbon dioxide are produced.
*Write a structural and chemical equation for the combustion of methane.
Rules for balancing chemical equations
The example we will use is the complete combustion of propane (C3H8) to produce
carbon dioxide and water.
Step 1: identify the reactants and products (word equation)
Step 2: Write down the chemical formula for reactants and products (chemical
equation)
Step 3: Balance the number of carbon atoms, by adding coefficients in front of the
formula.
Step 4: Balance the number of hydrogen atoms on each side.
Step 5: Ensure the oxygen atoms are balanced.
Step 6: Check equation and add states for the reactants and products.
Solid: ____________
Liquid: ___________
Aqueous: _________
Gas: _____________
Chemical Properties of alkenes
Alkenes like alkanes burn in oxygen to form carbon dioxide and water with the
release of heat. The presence of the double carbon-carbon bond (C = C) in alkenes
has a significant effect on their chemical ____________.
Alkenes react more readily and with more chemicals than ____________ . Ethene
and propene are starting materials (raw materials) used to manufacture many
compounds, eg antifreeze, alcohols and plastics.
Addition reactions of ethene
1. Reaction with bromine
Ethene reacts with bromine solution (Br2 dissolved in an organic solvent). In
addition reactions the double bond is converted to a single covalent bond.
Red brown colour of the Bromine disappears if a _______ bond is presence. This
is a general test for _____________ .
2. Reaction with hydrogen gas
In the presence of a catalyst and on heating, ethene reacts with ____________
gas to produce ___________ . Converting the double bond into a _________
covalent bond.
3. Reaction with Steam
Ethanol can be produced by the addition reaction of ________ and _________ in
the presence of phosphoric acid catalyst.
The ethanol produced in the above reaction is used for industrial purposes and as
solvents in cosmetics and inks, whereas ethanol used in alcoholic beverages is
fermented from sugars.
4. Formation of polyethene – addition polymerisation
The ethene molecules join themselves together to form a long chain.
Polymer: ____________
Monomer: ___________
QUESTIONS: