# A student dissolves a fizzing indigestion tablet in a beaker of water. The student notices the beaker feels slightly cooler to the touch after the tablet has dissolved. Explain what type of chemical reaction has taken place and describe what is happening to energy during this reaction.

> OCR GCSE Chemistry A: Gateway Science (J248) — C3.3 Types of chemical reactions · Explain · 4 marks

> Indigestion tablets contain sodium hydrogencarbonate, which reacts with excess acid in the stomach. A student investigates this reaction by placing a tablet in water and monitoring the temperature change.

## Mark scheme (4 marks)

1. The reaction is endothermic
2. Energy is taken in from the surroundings
3. The temperature of the surroundings decreases
4. The energy needed to break bonds in the reactants is greater than the energy released when bonds in the products are formed

## Related

- [Revision notes for OCR GCSE Chemistry A: Gateway Science (J248)](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-student-dissolves-a-fizzing-indigestion-f2a2192c) · Published by Druglandscape Ltd.