Calculate the heat of decomposition for this process at constant pressure and 25°C: CaCO3 (s) → CaO (s) + CO2 (g) The standard enthalpies of formation for the reactant are: ΔHf CaCO3 (s) = - 1206.9 kJ/mol; ΔHf CaO (s) = - 635.6 kJ/mol; ΔHf CO2 (g) - 393.5 kJ/mol

177.8kJ/mol

Explanation:

In this reaction, the heat of decomposition is the same as the heat of formation. This is a decomposition reaction.

Given parameters:

ΔHf CaCO₃ = - 1206.9kJ/mol

ΔHf CaO = - 635.6 kJ/mol

ΔHf CO₂ = - 393.5 kJ/mol

The heat of decomposition =

Sum of ΔHf of products - Sum of ΔHf of reactants

The equation of the reaction is shown below:

CaCO₃ → CaO + CO₂

The heat of decomposition = [ - 635.6 + (-393.5) ] - [-1206.9 ]

= - 1029.1 + 1206.9

= 177.8kJ/mol