Describe and explain how the solubilities of the hydroxides of the Group 2 elements change.
Reaction 1 is carried out by bubbling $\text{CO}_2(g)$ through an aqueous solution of $\text{Ba(OH)}_2$. Use the table data to calculate the standard enthalpy change for reaction 1, $\Delta H^{\circ}_{r1}$. $\text{Ba(OH)}_2(aq) + \text{CO}_2(g) \rightarrow \text{BaCO}_3(s) + \text{H}_2\text{O}(l)$.
Use the information provided here and the data in the table to calculate the standard enthalpy change of formation of the $\text{HCO}_3^{-}(aq)$ ion.
Reaction 3 shows the overall process. Use your answer to (ii), together with the data in the table, to calculate the standard enthalpy change for reaction 3, $\Delta H^{\circ}_{r3}$. $\text{Ba(OH)}_2(aq) + 2\text{CO}_2(g) \rightarrow \text{Ba(HCO}_3)_2(aq)$.
How would $\Delta H^{\circ}_{r3}$ compare with $\Delta H^{\circ}_{r4}$ for the comparable reaction using $\text{Ca(OH)}_2(aq)$ shown in reaction 4? Explain your response. $\text{Ca(OH)}_2(aq) + 2\text{CO}_2(g) \rightarrow \text{Ca(HCO}_3)_2(aq)$.
The standard entropy change for reaction 1 is $\Delta S^{\circ}_{r1}$. Suggest, with a reason, how the standard entropy change for reaction 3 could compare with $\Delta S^{\circ}_{r1}$.