Thermal Physics: Heat Capacity, Calorimetry, and Latent Heat

Vocabulary flashcards covering heat capacity, specific heat capacity, calorimetry, method of mixtures, and latent heat based on the provided lecture notes.

Heat Capacity ($C$)

The amount of heat required to raise the temperature of a substance by $1\,K$ or $1\,^\circ C$, calculated as $C = \frac{H}{\Delta \theta} = M c$ with SI units of $J/K$ or $J\,K^{-1}$.

Specific Heat Capacity ($c$)

The amount of heat required to raise the temperature of $1\,kg$ mass of a substance by $1\,K$ or $1\,^\circ C$, calculated as $c = \frac{H}{M \times \Delta \theta}$ with SI units of $J\,kg^{-1}\,K^{-1}$ or $J/kg\,K$.

Quantity of Heat ($H$ or $Q$)

The heat energy absorbed or lost by a substance, given by the expression $H = m \times c \times \Delta \theta = m c (\theta_2 - \theta_1)$.

Specific Heat Capacity of Water

The highest specific heat capacity among common listed substances, equal to $4200\,J\,kg^{-1}\,K^{-1}$.

Specific Heat Capacities of Common Substances

Values in $J\,kg^{-1}\,K^{-1}$ for standard materials: Ice ($2100$), Aluminium ($900$), Iron ($450$), Copper ($400$), Mercury ($150$), and Lead ($130$).

Practical Importance of Water's High SHC

Enables water to be used as a coolant in car engines to absorb large amounts of heat without overheating, helps regulate human body temperature through perspiration, and makes water ideal for boiling and steaming food.

Calorimetry

The measurement of heat flow in thermal processes.

Calorimeter

An instrument made of copper, lagged with an insulator inside a jacket with a plastic cover containing two holes for a thermometer and a stirrer.

Methods of Measuring Specific Heat Capacity

The two common experimental methods used to determine specific heat capacity: the Electrical method and the Method of mixtures.

Method of Mixtures Calorimeter Setup

An experimental arrangement consisting of a copper calorimeter containing water, surrounded by insulation lagging, equipped with a stirrer, thermometer, thread, and heat source.

Heat Conservation in Method of Mixtures

The equation based on energy conservation where heat lost by solid equals heat gained by water plus heat gained by calorimeter ($M_s C_s \Delta \theta = M_w C_w \Delta \theta + M_c C_c \Delta \theta$).

Latent Heat

The amount of heat absorbed or lost by a substance during a change of state without causing any change in temperature ('hidden heat').

Intermolecular Role of Latent Heat

Heat energy absorbed during a phase change that is used exclusively to break intermolecular forces holding particles together in a solid state, rather than increasing kinetic energy or temperature.