1. Calculate theheat of solution(q_rxn) for each trial. Find q_solnfirst. The heat of the dissolution (q_soln) is calculated using the formula q = -cmT where c is the heat capacity (approximated by the heat capacity of water as 4.184 Jg^-1-¹), m is the mass of the solution, and T is the temperature change. The heat capacity of the calorimeter will not be included in the calculation.
2. Calculate the H for each trial in kJ/mol using the heat of solution (q_rxn) and the moles of the solid.
3. he molar enthalpy change is just the heat of dissolution over n, the number of moles solid, or H = q / n. Since the temperature decreases, the reaction is endothermic and Ho should be positive.
4. Average the Hs for your trials.
5. Calculation of G^o: Look up the value of K_eqfor the solid used (The equilibrium constant, K_eq, is simply the number of moles of urea used to make a saturated solution divided by the total volume in L). The free energy change of the dissolution is calculated using the formula G^o= -RTlnK_eqwhere R is the gas constant (8.31451 J K-¹mol^-1) and T is the temperature in Kelvin.

The molar mass of urea is 60.06 grams per mol