Answer:
ΔHrxn = 178.3 kJ/mol
Explanation:
Using Hess's law, you can obtain ΔHrxn from ΔHf of products and reactants, thus:
Hess's law:
ΔHrxn = ∑nΔHf products - ∑nΔHf reactants
Where n are moles of reaction
Thus, from the reaction:
CaCO₃(s) → CaO(s) + CO₂(g)
ΔHrxn = ΔHf CaO(s) + ΔHf CO₂(g) - ΔHf CaCO₃(s)
ΔHrxn = -635.1kJ/mol + (-393.5kJ/mol) - (-1206.9kJ/mol)
ΔHrxn = 178.3 kJ/mol
Answer:
ΔHrxn for this reaction is 178.3 kJ/mol
Explanation:
Step 1: Data given
ΔH°f [CaCO3(s)] = –1206.9 kJ/mol
ΔH°f [CaO(s)] = –635.1 kJ/mol
ΔH°f [CO2(g)] = –393.5 kJ/mol
Step 2: The balance equation
CaCO3(s) --> CaO(s) + CO2(g)
Step 3: Calculate ΔHrxn
ΔHrxn = The sum of ΔHf of the products - ΔHf of the reactants
ΔHrxn = ((-393.5 kJ/mol) + (-635.1 kj/mol)) - (-1206.9 kJ/mol)
ΔHrxn = 178.3 kJ/mol
ΔHrxn for this reaction is 178.3 kJ/mol
