medicines, alloys, fertilisers • fertilisers and foods. foods. Making an alloy: • Identify the purpose of the chemicals in the chosen formulation and with class. 5.8.1.3 Chromatography can be Explain how 2 Describe a method for Required practical 12: Video clips used to separate mixtures chromatography separates chromatography. YouTube: and can give information to mixtures. Investigate how paper help identify substances. Describe what happens to chromatography can be Chromatography involves Suggest how substances during the used to separate and tell YouTube: a stationary phase and a chromatographic methods process of the difference between mobile phase. Separation can be used for chromatography. coloured substances. depends on the distribution distinguishing pure Students should of substances between the substances from impure Describe what the Rf value calculate Rf values. phases. substances. is and write instructions on how to calculate the Rf AT skills covered by this Interpret chromatograms value. practical activity: 1 and 4. The ratio of the distance and determine Rf values Use chromatograms to moved by a compound from chromatograms. work out Rf values. (centre of spot from origin) to the distance moved by Provide answers to an Describe how the solvent can be appropriate number of chromatographic methods expressed as its Rf value: significant figures. could be used to find out whether a substance was pure or not. WS 2.4, 2.6 MS 1a, 1c, 1d, 2a Different compounds have different Rf values in different solvents, can be used to help identify the
medicines, alloys, fertilisers and foods. • fertilisers • foods. Identify the purpose of the chemicals in the chosen formulation and with class. Making an alloy: 5.8.1.3 Chromatography can be used to separate mixtures and can give information to help identify substances. Chromatography involves a stationary phase and a mobile phase. Separation depends on the distribution of substances between the phases. The ratio of the distance moved by a compound (centre of spot from origin) to the distance moved by the solvent can be expressed as its Rf value: Different compounds have different Rf values in different solvents, can be used to help identify the Explain how chromatography separates mixtures. Suggest how chromatographic methods can be used for distinguishing pure substances from impure substances. Interpret chromatograms and determine Rf values from chromatograms. Provide answers to an appropriate number of significant figures. WS 2.4, 2.6 MS 1a, 1c, 1d, 2a 2 Describe a method for chromatography. Describe what happens to substances during the process of chromatography. Describe what the Rf value is and write instructions on how to calculate the Rf value. Use chromatograms to work out Rf values. Describe how chromatographic methods could be used to find out whether a substance was pure or not. Required practical 12: Investigate how paper chromatography can be used to separate and tell the difference between coloured substances. Students should calculate Rf values. AT skills covered by this practical activity: 1 and 4. Video clips YouTube: YouTube:
AQA-8464F-SOW-ANALYSIS.DOCX