Physics - Calorimetry

Heat is the internal energy of molecules in motion, measured in Joules ($J$) or Calories ($cal$). $1 \text{ cal} = 4.186 \text{ J} \approx 4.2 \text{ J}$.

Temperature is the degree of hotness or coldness of a body, representing the average kinetic energy of its molecules.

Heat Capacity ($C'$) is the amount of heat energy required to raise the temperature of the entire body by $1^\circ\text{C}$ or $1 \text{ K}$. Unit: $J \text{ K}^{-1}$ or $J \text{ } ^\circ\text{C}^{-1}$.

Specific Heat Capacity ($c$) is the heat required to raise the temperature of a unit mass ($1 \text{ kg}$ or $1 \text{ g}$) of a substance by $1 \text{ K}$ or $1^\circ\text{C}$. Unit: $J \text{ kg}^{-1} \text{ K}^{-1}$.

Water has an unusually high specific heat capacity ($c_{water} = 4200 \text{ J kg}^{-1} \text{ K}^{-1}$), making it an excellent coolant.

Principle of Calorimetry: For an insulated system, Heat energy lost by the hot body = Heat energy gained by the cold body.

Latent Heat is the heat energy absorbed or released during a change of phase (solid to liquid or liquid to gas) without any change in temperature.

Specific Latent Heat of Fusion ($L_f$) of ice is $336 \text{ J g}^{-1}$ or $3.36 \times 10^5 \text{ J kg}^{-1}$.

Specific Latent Heat of Vaporization ($L_v$) of steam is $2260 \text{ J g}^{-1}$ or $2.26 \times 10^6 \text{ J kg}^{-1}$.