# A sports drink manufacturer produces a new energy drink containing water, sugar, food colouring, vitamins and flavourings. Explain why this energy drink is described as a formulation rather than a pure substance, and explain how paper chromatography could be used to show that the food colouring in the drink is not a pure substance.

> WJEC A-Level Chemistry (Wales) — 1.3 Chemical bonding · Explain · 5 marks

## Mark scheme (5 marks)

1. A formulation is a mixture designed for a particular use / made up of exact quantities of pure substances
2. The energy drink contains more than one substance / element or compound not chemically combined, so it cannot be a pure substance
3. In paper chromatography the food colouring (mobile phase / solvent) travels up the paper (stationary phase), carrying the components of the colouring with it
4. Different substances in the food colouring travel different distances up the paper because they have different solubilities in the solvent
5. If the food colouring produces more than one spot on the paper, it is not a pure substance / a pure substance would produce only one spot

## Key terms

- [formulation](https://www.gradenine.co.uk/glossary/formulation)
- [pure substance](https://www.gradenine.co.uk/glossary/pure-substance)
- [paper chromatography](https://www.gradenine.co.uk/glossary/paper-chromatography)

## Related

- [Revision notes for WJEC A-Level Chemistry (Wales)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/a-sports-drink-manufacturer-produces-a-cc6cebbd) · Published by Druglandscape Ltd.