Thermal Properties of Matter | Class 11 Physics Notes

10.6 Specific Heat Capacity

Specific heat capacity is the amount of heat required to raise the temperature of unit mass of a substance by one degree Celsius or Kelvin. Experiments show that the heat required depends on the mass of the substance, the temperature change, and the nature of the substance. Heat capacity (S) of a substance is defined as S = ΔQ/ΔT, where ΔQ is the heat supplied to change temperature by ΔT. Specific heat capacity (s) is heat capacity per unit mass: s = (1/m)(ΔQ/ΔT). It is a unique property of each substance and depends on temperature. The SI unit is J kg⁻¹ K⁻¹. When the amount of substance is given in moles (μ), molar specific heat capacity C = (1/μ)(ΔQ/ΔT) is defined, with units J mol⁻¹ K⁻¹. For gases, molar specific heat capacities at constant pressure (C_p) and constant volume (C_v) are distinguished. Tables 10.3 and 10.4 list specific heat capacities of various substances and gases. Water has a notably high specific heat capacity, making it an effective coolant and affecting environmental temperature variations. The section includes examples illustrating these concepts.

📊 Diagram: Tables 10.3 and 10.4 listing specific heat capacities of substances and gases.

🔗 Connection: This section leads to calorimetry, the measurement of heat transfer, in the next section.

Table on page 8 (8×4)

Table on page 8 (6×3)