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Calculate the DH°rxn for the decomposition of calcium carbonate to calcium oxide and carbon dioxide. DH°f means delta or change of heat of formation DH°f [CaCO3(s)] = –1206.9 kJ/mol; DH°f [CaO(s)] = –635.1 kJ/mol; DH°f [CO2(g)] = –393.5 kJ/mol CaCO3(s) --> CaO(s) + CO2(g)

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Answer: +178.3 kJ

Step-by-step explanation:

The chemical equation follows:


CaCO_3(s)\rightarrow CaO(s)+CO_2(g)

The equation for the enthalpy change of the above reaction is:


\Delta H^o_(rxn)=[(1* \Delta H^o_f_((CaO(s))))+(1* \Delta H^0f_(CO_2)]-[(1* \Delta H^o_f_((CaCO_3(s))))]

We are given:


\Delta H^o_f_((CaO(s)))=-635.1kJ/mol\\\Delta H^o_f_((CaCO_3(s)))=-1206.9kJ/mol\\\Delta H^o_f_((CO_2(g)))=-393.5kJ/mol\\\Delta H^o_(rxn)=?

Putting values in above equation, we get:


\Delta H^o_(rxn)=[(1* (-635.1))+(1* (-393.5))]-[(1* (-1206.9))]

The DH°rxn for the decomposition of calcium carbonate to calcium oxide and carbon dioxide is +178.3 kJ

User Travis Tubbs
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