Give systematic names for the following compounds:
\pmb{(a)} BaCl_{2}\quad\quad \pmb{(b)} CrCl_{3}\quad\quad \pmb{(c)} PbS \quad\quad \pmb{(d)} Fe_{2}O_{3}STRATEGY
Try to figure out the number of positive charges on each cation by counting the number of negative charges on the associated anion(s). Refer to Figures 2.11 and 2.12 if you are unsure.
(a) Barium chloride No Roman numeral is necessary because barium, a group 2A element, forms only Ba^{2+}
(b) Chromium(III) chloride The Roman numeral III is necessary to specify the +3 charge on chromium (a transition metal)
(c) Lead(II) sulfide The sulfide anion (S^{2-}) has a double negative charge, so the lead cation must be doubly positive.
(d) Iron(III) oxide The three oxide anions (O^{2-}) have a total negative charge of -6 so the two iron cations must have a total charge of +6 Thus, each is Fe(III).