Question

What is the enthalpy of reaction for the

Answer 1

Answer:

656.3 kJ

endothermic

Answer 2

Answer:

$\boxed{\text{656.3 kJ/mol}}$

Explanation:

The formula for calculating the enthalpy change of a reaction by using the enthalpies of formation of reactants and products is:

$\Delta_{\text{r}}H^{\circ} = \sum \Delta_{\text{f}} H^{\circ} (\text{products}) - \sum\Delta_{\text{f}}H^{\circ} (\text{reactants})$

                         CaCO₃(s) ⟶ CaO(s) + CO₂(g)

ΔH°f/kJ·mol⁻¹:    -1207.1          -157.3    -393.5

$\begin{array}{rcl}\Delta_{\text{r}}H^{\circ} & = & [-157.3 + (-393.5)] - (-1207.1)\\& = & -550.8 +1207.1\\& = & \textbf{656.3 kJ/mol}\\\end{array}\\\\\text{The enthalpy of decomposition is } \boxed{\textbf{656.3 kJ/mol}}$