Keywords : Freshman Chemistry Chemical Thermodynamics Chemistry lessons This stack is an advertisement for a set of lessons on the first law of thermodynamics (as it is seen from the chemical point of view). This is the first set of lessons in the CheMentor series of software products. The set consists of six lessons and six tests which can be used on individual machines or on a networked system of Macs. They have been tested with Freshman students and received enthusiastic reviews. The basic ideas of system, surroundings, energy transfers (heat and work), internal energy, measurement of internal energy change (or E, if you like), enthalpy, measurement of enthalpy change, relation between enthalpy change and internal energy change, thermochemical equations and Hess's law are all covered. Product will include full documentation. See also the demos 'Chemistry Tutoring' (which outlines the CheMentor series in more detail) and 'The Chemistry Toolkit' - also the Shareware product 'The Molar Mass Calculator' - all of which are available from AOL (use Command-5 or the GoTo menu (File Search)).