State and explain whether the reaction between magnesium and hydrochloric acid will cause entropy to increase or decrease.
State and explain whether dissolving solid potassium chloride in water will lead to an increase or decrease in entropy.
State and explain whether steam condensing to water will lead to an increase or decrease in entropy.
Magnesium carbonate can decompose according to $\text{MgCO}_3(s) \rightarrow \text{MgO}(s) + \text{CO}_2(g)$, $\Delta H^\circ = +117\,\text{kJ mol}^{-1}$. Standard entropies are supplied. Calculate $\Delta G^\circ$ for this reaction at $298\,\text{K}$. Include the correct sign and give your answer to three significant figures.
Explain, with reference to $\Delta G^\circ$, why this reaction is more feasible at higher temperatures.
When heated, sodium hydrogencarbonate breaks down into sodium carbonate according to $2\text{NaHCO}_3(s) \rightarrow \text{Na}_2\text{CO}_3(s) + \text{CO}_2(g) + \text{H}_2\text{O}(g)$, $\Delta H^\circ = +130\,\text{kJ mol}^{-1}$, $\Delta S^\circ = +316\,\text{J mol}^{-1}\text{K}^{-1}$. Calculate the minimum temperature at which this reaction becomes spontaneous (feasible). Show your working.
The solubility of Group 2 sulfates falls down the Group. Explain this trend.