Main Page | See live article | Alphabetical index In chemistry, the standard molar entropy is the entropy content of one mole of substance, under conditions of standard temperature and pressure. By comparing the entropies of products and reactants in a chemical reaction, we can determine whether the reaction will go forward or backwards. It usually given the symbol S0, and the units J/mol·K (joules per kelvin per mole). This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.