standard molar entropy definition chemistry
From Wikipedia, the free encyclopedia. In chemistry, the standard molar entropy is the entropy content of one mole of substance, under standard conditions (not standard temperature and pressure). The standard molar entropy is usually given the symbol S Â°, and as units of joules per mole kelvin (J mol â1 K â1).Unlike standard enthalpies of formation, the value of S Â° is absolute. That is, an element in its standard state has a nonzero value of S Â° at room temperature.he standard molar entropy of a gas at STP includes contributions from: 1  The heat capacity of one mole of the solid from 0 K to the melting point (including heat absorbed in any changes between different crystal structures). 2  The latent heat of fusion of the solid.