Liquid

Liquid properties such as heat capacity can be calculated using the method available in the Liquid class. The method is based on a correlation and is named accordingly; for example, the cp_yaws() method uses Yaws’ coefficients to calculate the heat capacity for a range of temperatures.

class chemics.Liquid(formula)[source]

Liquid properties class.

Parameters:

formula (str) – Molecular formula of the liquid

Variables:

  • formula (str) – Molecular formula of the liquid

  • mw (float) – Molecular weight of the liquid in g/mol

cp_yaws(temp, cas=None, disp=False)[source]

Liquid heat capacity.

Liquid heat capacity as a function of temperature using Yaws’ coefficients [1]. The CAS(Chemical Abstracts Service) number may be required for some species.

\[C_p = A + B\,T + C\,T^2 + D\,T^3 + E\,T^4\]
Parameters:

  • temp (float) – Temperature of the liquid in Kelvin

  • cas (str, optional) – CAS number of the liquid, required for some species

  • disp (bool) – Display information about the calculation such as the CAS number, applicable temperature range in Kelvin, and values for regression coefficients.

Raises:

  • ValueError – If provided CAS number is not found.

  • ValueError – If multiple substances found for given formula.

  • ValueError – If gas chemical formula not found.

  • ValueError – If given temperataure is out of range for calculation.

Returns:

cp (float) – Heat capacity of the liquid in J/(mol⋅K)

Examples

>>> liquid = cm.Liquid('CBrF3')
>>> liquid.cp_yaws(250)
107.2774...

>>> liquid = cm.Liquid('C38H76')
>>> liquid.cp_yaws(400, cas='61828-17-9')
1307.0624...

References