CHEMISTRY · Multi-part · AP · Chemistry · Chemical Reactions · Chemical Reactions
Problem
Four laboratory processes are represented below. All species are shown with their physical states; coefficients are omitted for clarity.
Process I: H2O(l) → H2O(s)
Process II: 2 H2(g) + O2(g) → 2 H2O(l)
Process III: CaCO3(s) → CaO(s) + CO2(g)
Process IV: NaCl(s) ⇌ Na+(aq) + Cl−(aq)
Assume standard laboratory conditions unless otherwise stated.
(a) For each process, classify the change as physical or chemical. Support each classification using information from the symbolic representation.
(b) For Process II and Process IV, describe one macroscopic observation that would provide evidence supporting your classification in part (a).
(c) Choose one process you classified as a physical change and one you classified as a chemical change. For each selected process, describe what occurs at the particulate (molecular or ionic) level during the change.