(a)[1]
Explain the meaning of the term entropy of a system.
(b)[3]
State and explain whether each of the following processes gives a positive or negative entropy change. Do not include the entropy change of the surroundings: • liquid water at $80^\circ\text{C}$ is cooled to $60^\circ\text{C}$ • solid calcium chloride is added to water and the mixture is stirred • the change corresponding to the lattice energy of calcium chloride, $\Delta H_{\text{latt}}\ \text{CaCl}_2(s)$, occurs
(c(i))[1]
Give the complete name of the term $\Delta G^\circ$.
(c(ii))[2]
Describe how the temperature at which the reaction $\text{ZnCO}_3(s) \rightarrow \text{ZnO}(s) + \text{CO}_2(g)$ becomes spontaneous may be calculated. Include an equation in your answer.