# When ammonium chloride dissolves in water, the temperature of the water decreases. Explain what this temperature change tells us about the type of energy change occurring, and describe what happens to the energy of the surroundings during this process.

> Pearson Edexcel International GCSE Chemistry (4CH1) — 3.1 Energetics · Explain · 4 marks

> A student dissolves ammonium chloride crystals in water and measures the temperature of the solution every 30 seconds. The temperature drops by 8 °C over the course of the experiment.

## Mark scheme (4 marks)

1. The reaction is endothermic
2. Energy is taken in from the surroundings (by the reaction / by the ammonium chloride)
3. The temperature of the surroundings decreases / the surroundings lose energy
4. The enthalpy change / heat energy change of the reaction is positive (products have more energy than reactants)

## Key terms

- [surroundings](https://www.gradenine.co.uk/glossary/surroundings)

## Related

- [Revision notes for Pearson Edexcel International GCSE Chemistry (4CH1)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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