# Combustion of ethanol is used in spirit burners to heat water in calorimetry experiments. When ethanol burns, the temperature of the water in the calorimeter rises. Explain what this temperature rise tells us about the combustion of ethanol, and describe how calorimetry could be used to determine the enthalpy change of this reaction.

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

> A student uses a spirit burner containing ethanol to heat 200 g of water. The temperature of the water rises by 15 °C during the experiment.

## Mark scheme (4 marks)

1. The temperature of the water rises, so energy is transferred to the surroundings / water, meaning the combustion of ethanol is an exothermic reaction.
2. Calorimetry measures the amount of heat energy released (or absorbed) during a chemical reaction / Q = mcΔT is used to calculate the heat energy change.
3. The moles of ethanol burned are calculated (from the mass of ethanol used), and the heat energy Q is divided by the number of moles to give the molar enthalpy change.
4. The molar enthalpy change value is given a negative sign because the reaction is exothermic.

## Key terms

- [calorimetry](https://www.gradenine.co.uk/glossary/calorimetry)
- [enthalpy change](https://www.gradenine.co.uk/glossary/enthalpy-change)

## 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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Source: [GradeNine](https://www.gradenine.co.uk/q/combustion-of-ethanol-is-used-in-6dd8c5e8) · Published by Druglandscape Ltd.