C.1.4 Chromatography

GCSE AQA Chemistry C1.4 Chromatography

A complete lesson including exam questions, a chromatography introduction, animation explanation and practical.

Worksheet adapted from the AQA Chromatography practical. Student practical worksheet includes learning outcomes, method and then summary questions. Practical adapted to real life situation. Aim: Allura Red (E129) is a red food colouring that may be an allergen in allergic skin conditions. Use Chromatography to discover which of the following contain E129; Red Skittles, Red MnM’s or Red Smarties.

Success Criteria:
State what is separated in Chromatography.

Describe the process of Chromatography.

Explain how Chromatography works to separate mixtures.

Do Now: Exam style question. (Link to previous lesson)

Main:

1. Student investigation: context Allura Red (E129) is a red food colouring that may be an allergen in allergic skin conditions. Use Chromatography to discover which of the following contain E129; Red Skittles, Red MnM’s or Red Smarties.
   Students to complete the chromatography of sweets practical. Can be demoed for lower ability classes first. Practical sheet with method included. Students to discover Which sweet contains Allura Red? Answer MnM’s
2. Students to pack up and be sat down after the practical. How chromatography works can now be discussed (animation can be used). Key words solvent and solubility will need to be defined.
3. Students to complete the summary section of the practical sheet. HT can be introduced to Rf values.
   Plenary:
   Suggest question. Suggest why it is important to be able to identify the food colouring additives used in fizzy drinks. (1 Mark)
   Answer. To check if it is safe/allowed; so people can make an informed decision about drinking it; it is important for people with allergies to know.

PRACTICAL: Chromatography