Respuesta :

The enthalpy of reaction for the decomposition of calcium carbonate is 177.4  KJ/mole .

We know that the enthalpy of reaction can be obtained from the enthalpy of formation of the reactants and that of the products using the formula;

ΔHrxn = ΔHf (products) - ΔHf (reactants)

The heat of formation of the species are as follows;

ΔHf (CaCO3(s)) = −1206.9 KJ/mol

ΔHf (CaO(s)) =  - 636 KJ/mole

ΔHf (CO2(g)) = -393.5  KJ/mole

ΔHrxn = [( -393.5  KJ/mole ) + ( - 636 KJ/mole)] - [ −1206.9 KJ/mol]

ΔHrxn = 177.4  KJ/mole

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Answer:

First one is 656.3 and second is endothermic.

Explanation:

Edge Thermochemical Equations assignment