unit:J-PER-MOL-K
Energy needed to heat one mole of substance by 1 Kelvin, under standard conditions (not standard temperature and pressure STP). The standard molar entropy is usually given the symbol S, and has units of joules per mole kelvin ( $ J\cdot mol^{-1} K^{-1}$). Unlike standard enthalpies of formation, the value of S is an absolute. That is, an element in its standard state has a nonzero value of S at room temperature.