What are the values of the entropy changes (system, surroundings, and universe) for the cooling of 1 mol of O2 (g) from 298 K to O2 (l) at 90.19 K if the process is done a. Reversibly b. Irreversibly by placing the sample in liquid hydrogen at 13.96 K? Assume enthalpy change of vaporization is 6820 j/mol at 90.19 K and Cp = 7/2 R for the gas.