n a cryogenic experiment, oxygen gas is confined to a 2-dimensional surface at a temperature of 60 K. The oxygen molecule can rotate in the plane of the 2-dimensional surface but not in any other orientation. If the oxygen gas absorbs into the gas phase from the surface at the standard boiling point of oxygen, which is 90 K, how much energy is required to heat 1 micromole (10-6 mol) to the desorption temperature