| English | Specific heat capacity |
|---|---|
| Bahasa Melayu | Muatan haba tentu |
| 中文 | 比热容 |
Definition
The amount of heat needed to raise the temperature of 1 kg of a substance by 1 °C (or 1 K); measured in J kg⁻¹ °C⁻¹.
In exam terms
Specific heat capacity (symbol c) is the amount of heat needed to raise the temperature of 1 kg of a substance by 1 °C (or 1 K). It is a fixed property of the material, measured in J kg⁻¹ °C⁻¹.
The heat needed is Q = mcθ, where m is mass and θ the temperature change. For example, to heat 2 kg of water (c = 4200 J kg⁻¹ °C⁻¹) by 30 °C requires Q = mcθ = 2 kg × 4200 J kg⁻¹ °C⁻¹ × 30 °C = 252 000 J. Water's high value means it needs a lot of heat to warm up and releases a lot as it cools.
Do not confuse it with…
Do not confuse specific heat capacity with specific latent heat. Specific heat capacity is the heat per kg to change temperature by 1 °C (unit J kg⁻¹ °C⁻¹) using Q = mcθ; specific latent heat is the heat per kg to change state with no temperature change (unit J kg⁻¹) using Q = ml.
In Paper 2 this is asked as define specific heat capacity or calculate the heat needed in a mixing or heating problem. State it as the heat to raise 1 kg by 1 °C, always show Q = mcθ with units, and remember it is per kilogram, unlike heat capacity which is for the whole object.
Source: DSKP KSSM Physics Form 4 and 5 (Versi English) (Bahagian Pembangunan Kurikulum (BPK), KPM)