Extract and interpret information from graphs, charts and tables. Students should be clips: 4.2.2.4 The chlorophyll and other 1 Describe a method for paper Required practical 9: able to: pigments in plant leaves chromatography. investigate how paper YouTube: can be separated and chromatography can be suggest how Explain what happens to identified by used to separate and chromato-graphic YouTube: substances during the chromatography. tell the difference methods can be process of chromatography. Chromatography can be between coloured used for Describe to another student used to separate mixtures substances. Students distinguishing what the Rf value is and and can give information to should calculate Rf pure substances instructions on how to help identify substances. values. from impure calculate the Rf value. substances The ratio of the distance Chemistry AT 1 and 4 interpret moved by a compound and (centre of spot from origin) determine Rf to the distance moved by values from the solvent can be chromato-grams. expressed as its Rf value: Different compounds have different Rf values in different solvents, which can be used to help identify the compounds. The
Extract and interpret information from graphs, charts and tables. 4.2.2.4 The chlorophyll and other pigments in plant leaves can be separated and identified by chromatography. Chromatography can be used to separate mixtures and can give information to help identify substances. 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, which can be used to help identify the compounds. The Students should be able to: suggest how chromato-graphic methods can be used for distinguishing pure substances from impure substances interpret and determine Rf values from chromato-grams. 1 Describe a method for paper chromatography. Explain what happens to substances during the process of chromatography. Describe to another student what the Rf value is and instructions on how to calculate the Rf value. Required practical 9: investigate how paper chromatography can be used to separate and tell the difference between coloured substances. Students should calculate Rf values. Chemistry AT 1 and 4 clips: YouTube: YouTube:
AQA-8465-SOW-TOLD.DOCX