Heat Capacity – Relation between Cp and Cv | Derivation and Equations

Define Heat Capacity

Heat Capacity – Relation between Cp and Cv: Heat capacity is the amount of heat required to raise the temperature of a substance by 1 Kelvin. It usually measured in Joules per Kelvin (J/K).

What are Heat Capacity C, Cp, and Cv?

In physics, the heat capacity (symbol: C) of an object the measure of the amount of heat required to raise the temperature of the object by one unit of temperature. The SI unit of heat capacity is the joule per kelvin (J/K). The heat capacity of an object can also defined as the amount of energy required to raise the temperature of the object by 1°C.

An object determined by the type of material the object made of and the size of the object. The heat capacity of a material determined by the amount of energy required to raise the temperature of a unit of the material by 1°C. The heat capacity of an object also proportional to the object’s mass.

Heat Capacity Ratio

The heat capacity ratio is the ratio of the heat capacities of two substances. It used to measure the thermal conductivity of a material. Therefore the higher the heat capacity ratio, the better the material is at transferring heat.

Why Cp Greater than Cv?

• The Clausius-Clapeyron equation states that the slope of the vapor pressure curve of a liquid proportional to the reciprocal of the absolute temperature. In other words, as the temperature of a liquid increases, the vapor pressure of the liquid also increases. The Clausius-Clapeyron equation is used to calculate the vapor pressure of a liquid as a function of temperature.
• Therefore Clausius-Clapeyron equation can rearranged to solve for the vapor pressure of a liquid as a function of temperature:

P = (Cv/Cp) ( ln (T/T0))

where P is the vapor pressure of the liquid, Cv is the heat capacity of the vapor, and also Cp is the heat capacity of the liquid.

• The Clausius-Clapeyron equation used to calculate the vapor pressure of a liquid as a function of temperature.
• The Clausius-Clapeyron equation can rearranged to solve for the vapor pressure of a liquid as a function of temperature:

P = (Cv/Cp) ( ln (T/T0))

• where P is the vapor pressure of the liquid, Cv is the heat capacity of the vapor, and also Cp is the heat capacity of the liquid.
• When the temperature of a liquid increased, the vapor pressure of the liquid also increases. The Clausius-Clapeyron