Scheme of work Combined Science: Trilogy - Foundation Chemistry – Organic chemistry This resource provides guidance for teaching the Organic chemistry topic from our new GCSE Combined Science: Trilogy specification (8464). It has been updated from the draft version to reflect the changes made in the accredited specification. These changes are also reflected in the learning outcomes and opportunities to develop skills. The scheme of work is designed to be a flexible medium term plan for teaching content and development of the skills that will be assessed. It is provided in Word format to help you create your own teaching plan – you can edit and customise it according to your needs. This scheme of work is not exhaustive; it only suggests activities and resources you could find useful in your teaching. 5.7 Organic chemistry 5.7.1 Carbon compounds as fuels and feedstock Spec ref. Summary of the specification content Learning outcomes What most candidates should be able to do Suggested timing (hours) Opportunities to develop scientific communication skills Opportunities to develop and apply practical and enquiry skills Self/peer assessment Opportunities an resources Reference to past questions that indicate success 5.7.1.1 Crude oil is a finite resource found in rocks. Crude oil is the remains of an ancient biomass consisting mainly of plankton that was buried in mud. 1 Students can create a cartoon strip to illustrate the formation of crude oil (links to the Carbon Cycle in Biology). Make molecular models of the different sized hydrocarbons using two colours of jelly tots and cocktail sticks.
Crude oil is a mixture of a very large number of compounds. Most of the compounds in crude oil are hydrocarbons, which are molecules made up of hydrogen and carbon atoms only. Describe the composition of crude oil. Recall the symbols for hydrogen and carbon. Define hydrocarbon. 5.7.1.1 Most of the hydrocarbons in crude oil are hydrocarbons called alkanes. The general formula for the homologous series of alkanes is The four members of the alkanes are methane, ethane, propane and butane. Alkane molecules can be represented in the following forms: or Recognise substances as alkanes given their formulae in these forms. Students do not need to know the names of specific alkanes other than methane, ethane, propane and butane. WS 1.2. 1 Define the prefix: meth-, eth-, pro-, but- . Describe the formula and what it means. Describe alkane molecules of methane, ethane, propane, butane in a format like C2H6 and: Provide students with a table of hydrocarbon boiling points and ask them to plot a graph of the boiling points against number of carbons. Make molecular models of the different alkanes using plasticine and cocktail sticks or molecular sets 5.7.1.2 The many hydrocarbons in crude oil may be separated into fractions, each of which contains molecules with a similar Explain how fractional distillation works in terms of evaporation and condensation. 2 Describe the process of fractional distillation. Draw a fractionating column and label each Demonstrate fractional distillation of cherry cola. Video clips YouTube: YouTube:
5.7.1.3 Some properties of hydrocarbons depend on the size of their molecules, including boiling point, viscosity and flammability. These properties influence how hydrocarbons are used as fuels. The combustion of hydrocarbon fuels releases energy. During combustion, the carbon and hydrogen in the fuels are oxidised. The complete combustion of a hydrocarbon produces carbon dioxide and water. Recall how boiling point, viscosity and flammability change with increasing molecular size. Write balanced equations for the complete combustion of hydrocarbons with a given formula. Knowledge of trends in properties of hydrocarbons is limited to: boiling points viscosity flammability. WS 1.2, 4.1 1 Describe trends in properties of boiling point, viscosity and flammability of hydrocarbons with increasing molecular size. Describe the products of combustion of alkanes using a balanced equation. Students can investigate the flammability of heavy paraffin oil (alkane), butane and pentane on a deflagrating spoon and observing the colour of the flame. Compare this with products of a Bunsen flame (methane) with both the air hole open and closed (combustion apparatus with limewater and condensing tube). Video clips: 5.7.1.4 Hydrocarbons can be broken down (cracked) to produce smaller, more useful molecules. Cracking can be done by various methods including catalytic cracking and steam cracking. The products of cracking include alkanes and Describe in general terms the conditions used for catalytic cracking and steam cracking. Recall the colour change when bromine reacts with an alkene. Balance chemical equations as examples of cracking given the 2 Describe the process of cracking. Write balanced symbol equations for the cracking of alkanes given the formulae of the reactants and products. Describe examples to illustrate the usefulness of cracking. Demonstrate cracking liquid paraffin over aluminium oxide: Or class can do this practical on a microscale: Use bromine water to identify alkenes and Video clips YouTube: