Download Making and using alcohol

Starter
 Match the names of the carbon compounds to their
formulae
 Identify what type of formula it is and write out a
different version of the formula e.g. if I have used a
displayed formula, draw the structural formula
Learning objectives
• Describe the industrial production of ethanol from both
sugars and ethene.
• Outline the uses of ethanol and methanol.
• Explain, in terms of hydrogen bonding, the water
solubility and the relatively low volatility of alcohols.
• Classify alcohols into primary, secondary and tertiary
alcohols.
Making ethanol
 Two methods for making ethanol
 In pairs – each of you will have an information sheet on
one method. Read and summarise.
 Teach your partner about your method and fill in an
information table together.
10 minutes
Uses of alcohol
 Read the information on page 149
 Make concise notes on
 Ethanol in alcoholic drinks
 Ethanol as fuel
 Ethanol in methylated spirits
 Uses of methanol (write the equation for the combustion
of methanol)
Biofuels Brazil
Fermentation
 Practical
 Follow the instructions on the sheet
 Save the product – we will look at it next week and
attempt to distil it...
Properties of alcohols
 Physical properties
 The physical properties of alcohols are influenced by their
ability to form hydrogen bonds.
 Where do the hydrogen bonds form?
 Will alcohols have relatively high or low boiling points as a
results of the hydrogen bonds?
High
 Why?
Hydrogen bonds are the strongest type of
intermolecular force
 Volatility
 Hydrogen bonds means that alcohols are less volatile than
equivalent sized alkanes
 Compare the boiling points on page 150.
 Key definition – volatility – the ease that a liquid turns
into a gas. Volatility increases as boiling point decreases.
 If you were asked to compare and explain the differences
in boiling points of alcohols and alkanes, how would you
do it?
Solubility
 Alcohols dissolve in water.
 Why might this happen? Can you draw a diagram to
explain?
 The first 3 members of the alcohols homologous series are
all soluble in water.
 Solubility decreases as chain length increases.
 A larger part of the alcohol molecule is made up of a nonpolar carbon chain
 The hydrocarbon chain doesn’t form hydrogen bonds with
water molecules
Classification of alcohols
 Alcohols are classified into primary, secondary or tertiary
depending on the number of alkyl groups attached to the
carbon carrying the alcohol group, C-OH
 If the OH group is attached to a carbon which it is
attached to one (or no) other carbon then it is a primary
alcohol.
 E.g. Butan-1-ol or methanol
 If the –OH group is attached to a carbon which is
attached to two other carbons then it is a secondary
alcohol
 E.g. Propan-2-ol or butan-2-ol
 If the –OH group is attached to a carbon which is
attached to three other carbons then it is a tertiary
alcohol
 E.g. 2-methylbutan-2-ol
Questions
 Complete the questions on page 151
 For question 1 name and classify and draw a skeletal
and displayed formula for each of the alcohols
Homework
 Page 179
 Questions 1, 2, 3 and 4