Question

you may have noticed an (s) next to one of the products in some double replacement reactions. an (s) next to a compound signifies that it is an insoluble solid, also know as a precipitate. precipitates can be either cloudy or chunky substances of various colors in an ionic solution. to predict if a product in a double replacement reaction forms a precipitate, you need to use the solubility rules found here.
for each reaction below, use the drop-down menus to select which compound will form a precipitate.
note: it is possible that no precipitates form.
$na_2s + cd(no_3)_2 \
ightarrow cds + 2nano_3$
$fecl_3 + 3koh \
ightarrow 3kcl + fe(oh)_3$
$na_2co_3 + ba(no_3)_2 \
ightarrow baco_3 + 2nano_3$
done

Explanation:

1. For the first reaction: All nitrates are soluble, so $\text{NaNO}_3$ dissolves. Sulfides of transition metals like Cd are insoluble, so $\text{CdS}$ is the precipitate.
2. For the second reaction: All chlorides (except a few exceptions not including KCl) are soluble. Hydroxides of transition metals like Fe(III) are insoluble, so $\text{Fe(OH)}_3$ is the precipitate.
3. For the third reaction: All nitrates are soluble, so $\text{NaNO}_3$ dissolves. Carbonates of group 2 metals like Ba are insoluble, so $\text{BaCO}_3$ is the precipitate.

Answer:

1. $\text{CdS}$
2. $\text{Fe(OH)}_3$
3. $\text{BaCO}_3$