Chapter 17, Problem 17.13P

PRACTICE 17.13 Consider the thermal decomposition of calcium carbonate:

${\text{CaCO}}_{\text{3}}\left(\text{s}\right)\to \text{CaO}\left(\text{s}\right)+{\text{CO}}_{\text{2}}\left(\text{g}\right)$

(a) Use the data in Appendix B to calculate the standard free-energy change for this reaction at 25°C.

(b) Will a mixture of solid ${\text{CaCO}}_{\text{3}}$ , solid $\text{CaO}$ , and gaseous ${\text{CO}}_{\text{2}}$ at 1 atm pressure react spontaneously at 25°C to produce more $\text{CaO}$ and ${\text{CO}}_{\text{2}}$ ?

(c) Assuming that $\Delta H°$ and $\Delta S°$ are independent of temperature, estimate the temperature at which the reaction becomes spontaneous.