5. When calcium carbonate is heated, the following reaction occurs:
CaCOJ – CaO + COz (a)
The standard enthalpy of reaction for each substance is shown below.
Substance
AH, (kJ/mol)
-1206.9
-635.1
CO2 (9)
-393.5
What statements correctly classifies the decomposition of calcium carbonate
reaction?
CaCO3 (5)
CaO(s)
A-The reaction is endothermic because energy is released during the
reaction.
B-The reaction is endothermic because energy is absorbed during the
reaction.
C-The reaction is exothermic because energy is released during the
reaction.
D-The reaction is exothermic because energy is absorbed during the
reaction.
