Based on the third law of thermodynamics, the entropy can be obtained using the equation

•  Entropy is a state function that is often referred to as the ‘state of disorder’ of a system. 
• The third law of thermodynamics states that the entropy of a crystal at a temperature of zero Kelvin is equal to zero.

Based on the third law of thermodynamics, the entropy can be obtained using the equation ${\int }_0^{\mathrm{T}}{\mathrm{C}}_{\mathrm{p}}{\mathrm{T}}^{-1}\mathrm{dT}=\mathrm{S}$.