## Chemistry and Chemical Reactivity (9th Edition)

This problem requires familiarization with common cations and anions and their charges; there's not much that can be explained other than electron balancing is required (sum of the negative charges must be equal to the sum of the positive ones). $\begin{smallmatrix} Cation & Anion & Name & Formula \\ NH_4^+ & Br^- & ammonium\ bromide & NH_4Br \\ Ba^{2+} & S^{2-} & barium\ sulfide & BaS \\ Fe^{2+} & Cl^{-} & iron\ (||)\ chloride & FeCl_2 \\ Pb^{2+} & F^{-} & lead\ (||)\ fluoride & PbF_2 \\ Al^{3+} & CO_3^{2-} & aluminum\ carbonate & Al_2(CO_3)_2 \\ Fe^{3+} & O^{2-} & iron\ (|||)\ oxide & Fe_2O_3 \\ \end{smallmatrix}$