Question

The entropy change for a process can be determined experimentally in a variety of ways. One of these is to determine enthalpy and free energy values at a constant temperature and to solve for DS. For the reaction below, the Ksp value was determined by evaporating 750.0mL of a saturated solution to dryness and measuring the mass of the remaining solid. The DH value was determined using temperature change data when samples of the solid were dissolved in 50.0mL of pure water (recall that the specific heat of water is 4.184 J/g*oC). Assuming that all data were collected at 298K, determine the DS for the process:

NH4NO3 (s) ---> NH4+ (aq) + NO3-1 (aq)