Chapter 9, Problem 139A

Interpretation Introduction

Interpretation:

The given chemical equation needs to be determined. and whether a precipitate forms or not needs to be determined. $\text{PbS}\left(\text{s}\right){\text{+LiNO}}_{\text{3}}\left(\text{aq}\right)\to$

Concept introduction:

If two solutions are mixed, the ions in the resulting solution may react with each other. A double displacement reaction may take place. This can result in the formation of a precipitate, water and gas.

Answer to Problem 139A

The reaction does not occur.

$\text{PbS}\left(\text{s}\right){\text{+LiNO}}_{\text{3}}\left(\text{aq}\right)\to \text{NR}$

Explanation of Solution

In this case lead (II) having a 2+ ionic charge, sulfur contain $2-$, lithium and nitrate has a $1+$ and $1-$ charge respectively. Hence, the possible products formed in the given reaction are as follows:

$\text{PbS}\left(\text{s}\right){\text{+LiNO}}_{\text{3}}\left(\text{aq}\right)\to \text{Pb}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}\left(\text{aq}\right){\text{+Li}}_{\text{2}}\text{S}\left(\text{aq}\right)$

From the table, it is clear that sulfur is generally insoluble except for group 1 cations including Li. All nitrates are soluble. Therefore, there is no precipitate and that the reaction does not occur.

Conclusion

A precipitate is formed when two soluble salts combined together and produce a solid product.