State and explain the pattern seen in the thermal stability of the Group 2 nitrates.
Lead(II) nitrate, $\text{Pb}(\text{NO}_3)_2$, breaks down on heating in a way similar to the Group 2 nitrates. Write an equation for the decomposition of lead(II) nitrate.
Suggest how the ease of decomposition of $\text{Pb}(\text{NO}_3)_2$ would compare with that of $\text{Ba}(\text{NO}_3)_2$. Explain your answer. You may find it helpful to use the Data Booklet.
Barium ethanedioate, $\text{BaC}_2\text{O}_4$, breaks down on heating to give barium oxide and a mixture of two different gases. Construct an equation for the decomposition of barium ethanedioate.
An impure sample of $\text{BaC}_2\text{O}_4$, with a mass of $0.500\,\text{g}$, is placed into $50.0\,\text{cm}^3$ of $0.0200\,\text{mol dm}^{-3}$ acidified $\text{MnO}_4^-(aq)$, present in excess. A redox reaction occurs and all of the $\text{BaC}_2\text{O}_4$ reacts. The solution left behind, containing unreacted acidified $\text{MnO}_4^-(aq)$, is titrated with $0.0500\,\text{mol dm}^{-3}\,\text{Fe}^{2+}(aq)$. The end-point is obtained after $30.40\,\text{cm}^3$ of $0.0500\,\text{mol dm}^{-3}\,\text{Fe}^{2+}(aq)$ has been added. Relevant equations: $\text{C}_2\text{O}_4^{2-} \rightarrow 2\text{CO}_2 + 2e^-$ $\text{MnO}_4^- + 8\text{H}^+ + 5e^- \rightarrow \text{Mn}^{2+} + 4\text{H}_2\text{O}$ $\text{Fe}^{2+} \rightarrow \text{Fe}^{3+} + e^-$ Calculate the percentage by mass of $\text{BaC}_2\text{O}_4$ in the $0.500\,\text{g}$ impure sample. Show your working. $[M_r:\, \text{BaC}_2\text{O}_4 = 225.3]$
Barium hydroxide, $\text{Ba(OH)}_2$, is fully dissociated in aqueous solution. Calculate the pH of $0.120\,\text{mol dm}^{-3}\,\text{Ba(OH)}_2(aq)$ at $298\,\text{K}$.