Learning objectives / Learning outcomes / Specification link-up / Kerboodle
Students should learn:
·  the names and formulae of some simple alcohols, carboxylic acids and esters
·  how to show the structures of alcohols, carboxylic acids and esters. / Most students should be able to:
·  name an example of an alcohol, carboxylic acid and an ester
·  recognise the formula of an alcohol, carboxylic acid and ester.
Some students should also be able to:
·  explain the difference between an alcohol, a carboxylic acid and an ester
·  draw the structure of an alcohol, a carboxylic acid and an ester. / Alcohols contain the functional group —OH. Methanol, ethanol and propanol are the first three members of a homologous series of alcohols. [C3.6.1 a)]
Ethanoic acid is a member of the carboxylic acids, which have the functional group
—COOH. [C3.6.2 a)]
… Esters have the functional group —COO—… [C3.6.3 a)]
Represent the structures of alcohols in the following forms:

CH3CH2OH [C3.6]
Represent the structures of carboxylic acids in the following forms:

CH3COOH [C3.6] / Chapter map: Organic chemistry
Support: Organic molecules
Lesson structure / Support, Extend and Practical notes
Starters
Link-up – Show students a molecular model of an alkane, its displayed formula and molecular formula. Ask students to suggest what the link is between all of the images [they are all the same compound]. (5 minutes)
Definitions – Ask students to think back to the work they did in C1 Chapters 4, 5 and 6. Ask them to define the following key terms: organic compound, molecule, hydrocarbon, alkane, alkene. Support students by encouraging them to work in pairs and use their previous work and the Student Book to help them. Extend students by asking them to define a homologous series [chemical family] and give an example [e.g. alkane, alkene, alcohol]. (10 minutes)
Main
·  Give students an A4 sheet of paper and ask them to fold it into equal thirds. At the top of each third they should write the name of one homologous series from: alcohol, carboxylic acid and ester. On one side they should state the characteristics of that homologous series, using secondary sources such as the Student Book and the internet to help them. On the reverse they should draw displayed formulae of some examples of compounds that would be in that group.
·  Students could then use the school’s marking policy to review each other’s work, marking and making suggestions for improvements. Students could then work on the advice of their peers to improve their work before handing it to the teacher for marking.
Plenaries
Classification – Give students a set of three cards: a red card with the word ‘carboxylic acid’ on it, a blue card with ‘ester’ and a white card with ‘alcohol’. Show students different chemical names, formulae and diagrams of organic molecules. Students have to hold the correct card up to correctly identify which homologous series it belongs to. Support students by using simple organic compounds that they have met during the lesson. They can then look back at their notes to help them. Extend students by using unfamiliar organic compounds. (5 minutes)
Circle the group – On the interactive whiteboard, show students a selection of different complex organic molecules, which contain ester, alcohol and carboxylic acid functional groups. Ask for volunteers to circle and label the different functional groups. (5 minutes) / Support
You can create a ‘cut-and-stick’ activity about the different organic chemicals that students need to study. Students could create a table in which the column headings are ‘alcohol’, ‘carboxylic acid’ and ‘ester’. They could then cut and stick information and examples into the correct columns.
Extend
Ask students to name simple alcohols and carboxylic acids. The prefix is the same as those used for alkanes and alkenes, however the ending is specific to the homologous series.
Course / Subject / Topic / Pages
Chemistry / Chemistry / C3 5.1 Structure of alcohols, carboxylic acids and esters / Pages 250-251
Learning objectives / Learning outcomes / Specification link-up / Kerboodle
Students should learn:
·  the properties of alcohols
·  the main uses of alcohols
·  the products of the full oxidation of ethanol. / Most students should be able to:
·  describe the properties of alcohols (including their reaction with sodium and their oxidation to carboxylic acids)
·  state the main uses of alcohols
·  write a word equation for the combustion of an alcohol.
Some students should also be able to:
·  construct a balanced symbol equation for the combustion of an alcohol. [HT only] / Methanol, ethanol and propanol:
– dissolve in water to form a neutral solution
– react with sodium to produce hydrogen
– burn in air
– are used as a fuels and solvents, and ethanol is the main alcohol in alcoholic drinks.
[C3.6.1 b)]
Ethanol can be oxidised to ethanoic acid, either by chemical oxidising agents or by microbial action. Ethanoic acid is the main acid in vinegar. [C3.6.1 c)] / Practical: Comparing the reactions of ethanol, methanol and propanol
How Science Works: A burning question
Lesson structure / Support, Extend and Practical notes
Starters
Connection – Show students an image of a fermentation vessel, a bottle of beer, gasohol station and a bottle of methylated spirit. Ask students to say how all the images are similar [they all contain alcohol]. Support students by encouraging them to think back to the work that they completed in C1 Chapter 5.5 Ethanol. Extend students by asking them to find out more about the constituents of methylated spirits. (5 minutes)
Remember – Ask students to recall the products of complete combustion of a hydrocarbon. Encourage students to write a general equation for combustion of a saturated hydrocarbon [hydrocarbon 1 oxygen → carbon dioxide 1 water]. You could extend Higher Tier students by encouraging them to write a general symbol equation for this reaction:
[CxH2x+2 + (3x + 1)O2 → xCO2 + (x + 1)H2O].
Give students some examples of hydrocarbons and ask them to use their general equation to write specific equations for the combustion of these saturated hydrocarbons.
(10 minutes)
Main
·  Allow students to set up a solution of ethanol (less than 15 per cent by volume) and monitor its pH over a number of days (see ‘Practical support’ for more details). Once students have set the experiment up encourage them to make a prediction using scientific ideas in their work.
·  Allow students to observe the combustion of different alcohols (see ‘Practical support’ for more details). Encourage students to draw the displayed formula of each alcohol, and write an equation for the reaction that is occurring. Their observations could be recorded in an appropriate results table.
·  Ask students to create a spider diagram to show the different reactions of ethanol. Students should have the word ethanol in the centre of the page and then add information about the reactions that it undergoes. Higher Tier students could include a balanced symbol equation for the combustion reaction.
Plenaries
Finish the equation – Ask students to finish the following equations:
ethanol 1 [oxygen] → carbon dioxide 1 [water]
methanol 1 oxygen → [carbon dioxide] 1 [water]
Support students by giving them the missing words. Extend students by asking them to write balanced symbol equations for each reaction and to classify the reactions [oxidation or combustion]. (5 minutes)
Flow chart – Ask students to make a flow chart to explain how ethanol is oxidised when it is open to the air. Support students by giving them the outline of the flow chart. (10 minutes) / Support
Give students information about the combustion of the three alcohols. They could then cut-and-stick this information to create their results table.
Extend
Students could use a data logger to monitor the pH of a solution of ethanol as detailed in the ‘Practical support’. Ask students to print out the data as a graph and add a curve of best fit. Encourage students to annotate the graph to explain the shape of the curve of best fit using oxidation of ethanol in their answers.
Practical support
Comparing the reactions of methanol, ethanol and propanol
Equipment and materials required
Three spirit burners, methanol, ethanol, propanol, sodium metal kept under oil, dry boiling tube, boiling-tube holder, tweezers, white tile, filter paper, scalpel, eye protection and safety screen.
Details
Allow students to ignite each of the spirit burners and observe the flame produced. As a demonstration, wearing eye protection, add 10 cm3 of ethanol to a dry Petri dish. Cut a piece of sodium (maximum 2 mm square) and wipe off the excess oil with filter paper. Using the tweezers, drop the sodium metal into the ethanol and observe. Ensure all of the sodium has reacted before disposing of the solution formed.
Safety: CLEAPSS Hazcard 88 Sodium – highly flammable; CLEAPSS Hazcard 40B Methanol – highly flammable/toxic; CLEAPSS Hazcard 40A Ethanol – harmful/highly flammable; CLEAPSS Hazcard 84A Propanol – highly flammable/irritant. For spirit burners see CLEAPSS Guide L195 ‘Safe chemicals, safer reactions’.
Oxidation by microbes in air
Equipment and materials required
Ethanol, universal indicator, 100 cm3 conical flask, 100 cm3
measuring cylinder, 10 cm3 measuring cylinder.
Details
Measure 50 cm3 of tap water to a conical flask. Add a few drops of universal indicator and then add 5 cm3 of ethanol. Leave the conical flask on a window sill and observe the change in pH over the course of several weeks, swirling the flask occasionally. Keep an identical stoppered flask to compare it with. This experiment works better with beer that has had carbon dioxide removed (shaking or boiling) because flies carrying the microbes are attracted by the smell.
Safety: CLEAPSS Hazcard 40A Ethanol – harmful/highly flammable; CLEAPSS Hazcard 32 Universal indicator – highly flammable/irritant.
Course / Subject / Topic / Pages
Chemistry / Chemistry / C3 5.2 Properties and uses of alcohol / Pages 252-253
Learning objectives / Learning outcomes / Specification link-up / Kerboodle
Students should learn:
·  how to recognise carboxylic acids from their properties
·  the uses of carboxylic acids and esters
·  why carboxylic acids are described as weak acids [HT only]
·  how esters can be made. / Most students should be able to:
·  describe the properties and an example of a carboxylic acid
·  state a use of a carboxylic acid and an ester
·  describe how to make an ester.
Some students should also be able to:
·  explain the difference between strong and weak acids in terms of ionisation [HT only]
·  explain why carboxylic acids are categorised as weak acids. [HT only] / Carboxylic acids:
– dissolve in water to produce acidic solutions
– react with carbonates to produce carbon dioxide
– react with alcohols in the presence of an acid catalyst to produce esters
– do not ionise completely when dissolved in water and so are weak acids [HT only]
– aqueous solutions of weak acids have a higher pH value than aqueous solutions
of strong acids with the same concentration [C3.6.2 b)] [HT only]
Ethyl ethanoate is the ester produced from ethanol and ethanoic acid. Esters have the functional group —COO—. They are volatile compounds with distinctive smells
and are used as flavourings and perfumes. [C3.6.3 a)]
Controlled Assessment: C4.1 Plan practical ways to develop and test candiates’ own scientific ideas. [C4.1.1 c)]; C4.3 Collect primary and secondary data.
[C4.3.2 a)] / Bump up your grade: Organic molecules
Extension: Identifying organic molecules
Support: Making sense of organic molecules
Lesson structure / Support, Extend and Practical notes
Starters
Group – Give students a written selection of 10 different compounds, all of which should be esters, carboxylic acids or alcohols. Some of the compounds should be given as a molecular formula, some as a structural formula and some as a displayed formula. Ask the students to group the compounds by the chemical family (homologous series) they belong to. Support students by giving them a brief definition of each homologous series. Extend students by asking them to try to name the compounds. (5 minutes)
Explain – Ask students to explain how they would find out which of two acids (of equal concentration) is strong and which is weak [pH scale/common reactions]. Give students time to think about the question individually. Then split the class into four groups. Ask each group to decide on the method and feed back to the class. (10 minutes) [HT only]
Main
·  Allow students to compare ethanoic acid (a weak acid) with hydrochloric acid (a strong acid). Extend students by asking them to write word equations for the reactions with sodium carbonate.
·  Encourage students to reflect on their method and results. Students should be able to suggest that their conclusions about the relative strength of the acids are valid only if the concentration of the two acids is the same. They should also appreciate that using a pH sensor rather than universal indicator gives improved accuracy when finding pH values.
·  Carefully explain the difference between strong and weak acids as opposed to concentrated and dilute solutions of acids. Ask how they can have a solution of a strong acid (high degree of ionisation/dissociation) but with a relatively high pH value, e.g. 5 [very dilute solution]. [HT only]
·  Create a card sort made up of 30 questions and their answers on separate cards. The questions should range from easy questions such as ‘Which functional group is in an alcohol?’ to examination-style questions including equations and summary questions. Students should match the questions with their answers. This activity can be differentiated by giving fewer questions to some students. Students could also work in teams.
·  Then ask students to pick five of the questions, together with their answers, and record them in their notes.
Plenaries
Bingo – Make bingo cards with six answers on the card, including key words – e.g. ester, alcohol, carboxylic acid, organic chemical. Then ask questions. The students cross off the answer if it appears on their bingo card. The first student to call ‘house’ (with all the answers) is the winner and could get a prize. (5 minutes)