Chemistry — Third Law & Absolute Entropy

S \rightarrow 0 \text{ as } T \rightarrow 0\ \text{(perfect crystal)}

S = \int_0^T \frac{C_p}{T}\,dT

S^\circ = \text{absolute standard entropy}

\Delta S^\circ = \sum S^\circ_{prod} - \sum S^\circ_{react}