what is difrent between cp and cv
cp is constant pressure
cv is constant volume
Both C's are specific heats. Cp is the specific hear at constant pressure and Cv is the specific heat at cosnatnt volume. (The C is usually capitalized and the p or v is usually a subscript).
For an ideal gas, Cp = Cv + R,
where R is the ideal gas constant, 1.986 calories per mole per degree C.
The difference between Cp (specific heat capacity at constant pressure) and Cv (specific heat capacity at constant volume) lies in the conditions under which the quantities are measured.
Cp refers to the amount of heat required to raise the temperature of a substance by one degree Celsius while keeping the pressure constant. It is typically used in processes occurring at constant pressure, such as open systems or systems where heat is transferred to or from the surroundings. Cp is typically higher than Cv because, in addition to the energy required to increase the internal energy of the system, heat is also used to do work against the external pressure.
On the other hand, Cv refers to the amount of heat required to raise the temperature of a substance by one degree Celsius while keeping the volume constant. It is used in processes occurring at constant volume, such as closed systems where no work is done against external pressure. Cv is generally lower than Cp because no work is done against pressure, resulting in fewer degrees of freedom for energy exchange.
To determine the specific heat capacities (Cp and Cv) for a substance, experimental techniques are employed. These techniques involve measuring the change in temperature of the substance when a known amount of heat is added or removed while keeping either the pressure or the volume constant. These measurements can then be used to calculate the specific heat capacities.
It is worth noting that Cp and Cv are intensive properties, meaning they depend on the nature of the substance but not on the quantity of the substance. Therefore, the values of Cp and Cv will differ for different substances.