Chemistry

Problem

The thermal decomposition of calcium carbonate is described by

\text{CaCO}_3(s)\rightarrow \text{CaO}(s)+\text{CO}_2(g)\qquad \Delta H^{\circ}=+178\,\text{kJ}

Given:

\Delta H_f^{\circ}(\text{CaCO}_3\text{(s)}) = -1207\,\text{kJ mol}^{-1}

\Delta H_f^{\circ}(\text{CO}_2\text{(g)}) = -393.5\,\text{kJ mol}^{-1}

Determine

\Delta H_f^{\circ}(\text{CaO}\text{(s)})

. a)

+5.72\times10^{2}\,\text{kJ mol}^{-1}

-2.15\times10^{2}\,\text{kJ mol}^{-1}

-6.36\times10^{2}\,\text{kJ mol}^{-1}

-9.92\times10^{2}\,\text{kJ mol}^{-1}