Specify what ions are present upon dissolving each of the following substances in water: (a) \(\mathrm{MgI}_{2,}\) (b) \(\mathrm{K}_{2} \mathrm{CO}_{3,}$$(\mathbf{c})$$\mathrm{HClO}_{4,}\) \((\mathbf{d}) \mathrm{NaCH}_{3} \mathrm{COO.}\)

When magnesium iodide (\(\mathrm{MgI}_2\)) is dissolved in water, it dissociates into its component ions: one magnesium ion and two iodide ions. These ions are represented as: $$ \mathrm{MgI}_{2} \rightarrow \mathrm{Mg}^{2+}(aq) + 2\mathrm{I}^{-}(aq) $$

When potassium carbonate (\(\mathrm{K}_2 \mathrm{CO}_3\)) is dissolved in water, it dissociates into its component ions: two potassium ions and one carbonate ion. These ions are represented as: $$ \mathrm{K}_{2} \mathrm{CO}_{3} \rightarrow 2 \mathrm{K}^{+}(aq) + \mathrm{CO}_3^{2-}(aq) $$

When perchloric acid (\(\mathrm{HClO}_4\)) is dissolved in water, it dissociates into its component ions: one hydrogen ion (proton) and one perchlorate ion. These ions are represented as: $$ \mathrm{HClO}_4 \rightarrow \mathrm{H}^{+}(aq) + \mathrm{ClO}_4^{-}(aq) $$

When sodium acetate (\(\mathrm{NaCH}_3 \mathrm{COO}\)) is dissolved in water, it dissociates into its component ions: one sodium ion and one acetate ion. These ions are represented as: $$ \mathrm{NaCH}_3 \mathrm{COO} \rightarrow \mathrm{Na}^{+}(aq) + \mathrm{CH}_3 \mathrm{COO}^{-}(aq) $$ To summarize, the ions produced when the given substances are dissolved in water are: (a) \(\mathrm{MgI}_2\): \(\mathrm{Mg}^{2+}(aq)\) and \(2\mathrm{I}^{-}(aq)\) (b) \(\mathrm{K}_2\mathrm{CO}_3\): \(2\mathrm{K}^{+}(aq)\) and \(\mathrm{CO}_3^{2-}(aq)\) (c) \(\mathrm{HClO}_4\): \(\mathrm{H}^{+}(aq)\) and \(\mathrm{ClO}_4^{-}(aq)\) (d) \(\mathrm{NaCH}_3\mathrm{COO}\): \(\mathrm{Na}^{+}(aq)\) and \(\mathrm{CH}_3\mathrm{COO}^{-}(aq)\)