Answer
(a) NaNO$_3$
(b) Be(OH)$_2$
(c) NH$_4$CH$_3$COO
(d) K$_2$SO$_3$
Work Step by Step
(a) NaNO$_3$
Sodium (Na) is an alkali metal and has a valence of 1+. We refer to the table of polyatomic anions (Table 2.2) on page 65 of the book to find the formula and charge for nitrite (NO$_3$$^-$). We will need one sodium ion for every one nitrite ion to balance the charges in this compound.
(b) Be(OH)$_2$
Beryllium (Be) is an alkaline earth metal and has a valence of 2+. We refer to the table of polyatomic anions (Table 2.2) on page 65 of the book to find the formula and charge for hydroxide (OH$^-$). We will need one beryllium ion for every two hydroxide ions to balance the charges in this compound.
(c) NH$_4$CH$_3$COO
Ammonium (NH$_4$$^+$) has a valence of 1+. We refer to the table of polyatomic anions (Table 2.2) on page 65 of the book to find the formula and charge for acetate (CH$_3$COO$^-$). We will need one ammonium ion for every one acetate ion to balance the charges in this compound.
(d) K$_2$SO$_3$
Potassium (K) is an alkali metal and has a valence of 1+. We refer to the table of polyatomic anions (Table 2.2) on page 65 of the book to find the formula and charge for sulfite (SO$_3$$^2-$). We will need two potassium ions for every one sulfite ion to balance the charges in this compound.