Question

making predictions about reactions
choose the correct products for the double replacement reaction below. click here to access the solubility rules to determine which product, if any, forms a solid precipitate in the reaction.
$\text{pbcl}_2 + \text{mgso}_4
ightarrow ?$
$\text{pb} + \text{o}_2 + \text{mgcl}$
$\text{pbmg} + \text{clso}_4$
$\text{pbso}_4 + \text{mgcl}_2$
$\text{pb(so}_4\text{)}_2 + \text{mgcl}$
which product in the reaction forms a precipitate?
$\text{pbso}_4$
$\text{mgcl}_2$
$\text{pbmg}$
no precipitate forms
done
complete

Explanation:

1. For double replacement reactions, cations and anions swap partners. For $\text{PbCl}_2 + \text{MgSO}_4$, lead(II) pairs with sulfate, and magnesium pairs with chloride, forming $\text{PbSO}_4 + \text{MgCl}_2$.
2. Using solubility rules: Most sulfate salts are soluble, but $\text{PbSO}_4$ is an insoluble exception. $\text{MgCl}_2$ is a soluble chloride salt. Thus, $\text{PbSO}_4$ forms a precipitate.

Answer:

Correct reaction products: $\text{PbSO}_4 + \text{MgCl}_2$
Precipitate-forming product: $\text{PbSO}_4$