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)
To determine the entropy change (ΔS) for the given process, we would need to use the information about the enthalpy change (ΔH) and the free energy change (ΔG).
Given that the enthalpy change (ΔH) was determined using temperature change data and the specific heat of water, we first need to calculate the heat absorbed or released during the dissolution of NH4NO3 in water.
The heat change (q) can be calculated using the equation:
q = mcΔT
Where:
q = heat change
m = mass of the sample (NH4NO3)
c = specific heat capacity of water (4.184 J/g*°C)
ΔT = change in temperature (°C)
However, to use this equation, we need the mass of the sample (NH4NO3) and the change in temperature (ΔT), which are not provided in the given information. So, we cannot determine the enthalpy change (ΔH) directly.
Similarly, the free energy change (ΔG) cannot be determined without knowing the concentrations of NH4+ and NO3- ions in solution.
Therefore, without the necessary data, it is not possible to directly determine the entropy change (ΔS) for the given process.