A laboratory route for preparing aqueous calcium chloride involves reacting solid…
CHEMISTRY · Multi-part · A Level · Chemistry · Energetics · Energetics
Problem
A laboratory route for preparing aqueous calcium chloride involves reacting solid calcium carbonate with hydrochloric acid, followed by dissolving the gaseous carbon dioxide produced. The simplified sequence at 298 K is described below.| Step | Chemical transformation | ΔH (kJ mol⁻¹) |
|---|---|---|
| 1 | CaCO₃(s) + 2 HCl(aq) → CaCl₂(aq) + H₂O(l) + CO₂(g) | –171.5 |
| 2 | CO₂(g) → CO₂(aq) | –19.4 |