A researcher investigates four transformations of solid substances at 1 atm pressure.
CHEMISTRY · Multi-part · AP · Chemistry · Chemical Reactions · Chemical Reactions
Problem
A researcher investigates four transformations of solid substances at 1 atm pressure.
(a) For EACH transformation, indicate whether it is best described as a physical change or a chemical change. Provide brief reasoning in each case.
(b) The researcher proposes using the magnitude of the enthalpy change, ∣ΔH∣, as a quantitative proxy for the extent of chemical bond disruption. Outline a procedure the researcher could use to test this proposal using calorimetric measurements for the four transformations.
(c) Predict which transformation would have the largest ∣ΔH∣ value per mole of solid and justify your prediction with reference to bond energies and phase changes.