**Calorimetry **is used to find the amount of heat released or absorbed during a reaction. A simple method relies on using the heat to warm up a known mass of water by a known amount.

**Specific heat capacity** is the energy required to raise the temperature of 1 g of a substance by 1 °C.

The equation below is used to work out how much heat is absorbed by the water:

* **q* = *m* × *c* × Δ*T* where *q* = heat energy, J

*m* = mass of water, g

*c* = 4.2 J g–1 K–1

Δ*T* = change in temperature, K

Note that 100 cm3 of water has a mass of 100 g, *c* is the specific heat capacity of water, and a change in temperature by 1 °C is also a change by 1 K.

*A bomb calorimeter can be used to accurately measure heats of combustion.*

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