A 1.50g sample of an unknown white crystalline solid, labeled \"compound X,\" is added to 100.0g of water initially at 22.00∘C in an insulated coffee-cup calorimeter. The final temperature of the solution is 24.35∘C. The specific heat capacity of the solution may be taken as 4.18Jg−1∘C−1, and no heat is absorbed by the calorimeter itself.
A separate qualitative test shows that the resulting solution conducts electricity strongly.
(a) Calculate the heat absorbed or released by the water during the dissolution of compound X.
(b) Determine the molar enthalpy of dissolution, ΔHsoln, for compound X, given that its molar mass is 95.0gmol−1. Indicate whether the process is endothermic or exothermic.
(c) Suggest two possible microscopic reasons (one structural, one energetic) that could account for both the observed temperature change and the electrical conductivity.
(d) Based on your answers above, argue whether the dissolution of compound X should be classified as a physical change, a chemical change, or is best described as ambiguous. Justify your conclusion thoroughly.