Determine the Standard Enthalpy of Formation of Calcium Carbonate from the Thermochemical

Multiple Choice

Determine the standard enthalpy of formation of calcium carbonate from the thermochemical equations given below. $$\begin{array} { l l } \mathrm { Ca } ( \mathrm { OH } ) _ { 2 } ( \mathrm {~s} ) \rightarrow \mathrm { CaO } ( \mathrm { s } ) + \mathrm { H } _ { 2 } \mathrm { O } ( \ell ) & \Delta _ { r } H ^ { \circ } = 65.2 \mathrm {~kJ} / \mathrm { mol } - \mathrm { rxn } \\\mathrm { Ca } ( \mathrm { OH } ) _ { 2 } ( \mathrm {~s} ) + \mathrm { CO } _ { 2 } ( \mathrm {~g} ) \rightarrow \mathrm { CaCO } _ { 3 } ( \mathrm {~s} ) + \mathrm { H } _ { 2 } \mathrm { O } ( \ell ) & \Delta _ { r } H ^ { \circ } = - 113.8 \mathrm {~kJ} / \mathrm { mol } - \mathrm { rxn } \\\mathrm { C } ( \mathrm { s } ) + \mathrm { O } _ { 2 } ( \mathrm {~g} ) \rightarrow \mathrm { CO } _ { 2 } ( \mathrm {~g} ) & \Delta _ { r } H ^ { \circ } = - 393.5 \mathrm {~kJ} / \mathrm { mol } - \mathrm { rxn } \\2 \mathrm { Ca } ( \mathrm { s } ) + \mathrm { O } _ { 2 } ( \mathrm {~g} ) \rightarrow 2 \mathrm { CaO } ( \mathrm { s } ) & \Delta _ { r } H ^ { \circ } = - 1270.2 \mathrm {~kJ} / \mathrm { mol } - \mathrm { rxn }\end{array}$$

A) ?1712.3 kJ/mol-rxn
B) ?441.8 kJ/mol-rxn
C) ?849.6 kJ/mol-rxn
D) ?980.6 kJ/mol-rxn
E) ?1207.6 kJ/mol-rxn