what is the enthalpy of reaction for the decomposition of calcium carbonate? caco3(s)→cao(s)+co2(g) this…
what is the enthalpy of reaction for the decomposition of calcium carbonate? caco3(s)→cao(s)+co2(g) this reaction is endothermic exothermic
Answer
Explanation:
Step1: Recall enthalpy - reaction formula
$\Delta H_{rxn}=\sum n\Delta H_f(products)-\sum m\Delta H_f(reactants)$
Step2: Identify products and reactants and their coefficients
For $CaCO_3(s)\rightarrow CaO(s)+CO_2(g)$, $n_{CaO}=1$, $n_{CO_2}=1$, $m_{CaCO_3}=1$
Step3: Substitute the standard - enthalpy of formation values
$\Delta H_{rxn}=\Delta H_f(CaO)+\Delta H_f(CO_2)-\Delta H_f(CaCO_3)$ $\Delta H_{rxn}=(- 157.3)+(-393.5)-(-1207.1)$
Step4: Calculate the enthalpy of reaction
$\Delta H_{rxn}=-157.3 - 393.5 + 1207.1$ $\Delta H_{rxn}=656.3$ kJ
Since $\Delta H_{rxn}=656.3$ kJ>0, the reaction absorbs heat.
Answer:
656.3 kJ, endothermic