| English | Heat capacity |
|---|---|
| Bahasa Melayu | Muatan haba |
| 中文 | 热容量 |
Definition
The amount of heat needed to raise the temperature of an object by 1 °C (or 1 K); measured in J °C⁻¹ or J K⁻¹.
In exam terms
Heat capacity is the amount of heat needed to raise the temperature of a whole object by 1 °C (or 1 K). It is a property of the particular object, not the material alone, and it is measured in J °C⁻¹ or J K⁻¹.
It is given by C = Q/θ, so Q = Cθ. A larger object of the same material has a larger heat capacity.
For example, if 8000 J raises the temperature of a metal block by 4 °C, its heat capacity is C = Q/θ = 8000 J ÷ 4 °C = 2000 J °C⁻¹, meaning 2000 J is needed for each 1 °C rise.
Do not confuse it with…
Do not confuse heat capacity with specific heat capacity. Heat capacity applies to a whole object (unit J °C⁻¹) and depends on how much material is present; specific heat capacity is per kilogram of a substance (unit J kg⁻¹ °C⁻¹) and is a fixed property of the material.
Heat capacity = mass × specific heat capacity.
In Paper 2 this is asked as define heat capacity or state the difference between heat capacity and specific heat capacity. State that heat capacity is for the whole body while specific heat capacity is for 1 kg of the substance, and give the correct units for each.
Source: DSKP KSSM Physics Form 4 and 5 (Versi English) (Bahagian Pembangunan Kurikulum (BPK), KPM)