Consider the following reactions and their ÎH values. What is the Î for the indicated target reaction? Reaction 1: Reaction 2: Reaction 3 CaCO3 (s) â CaO (s) + CO2 (g) Ca(OH)2 (s) â Cao (s) +H2O(1) Ca(OH)2 (s) + 2HCI (g) â 2H20 (D+CaCl2 (s) AH--218. Target: CaCO3 (s) + 2 HCI (g) CaCl2 (s) + H2O () + CO2 (g) AH â