Will precipitation occur when the following solutions are mixed? If so, write a balanced chemical equation for the reac- tion. (a) \(\mathrm{Ca}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2}\) and \(\mathrm{NaOH},(\mathbf{b}) \mathrm{K}_{2} \mathrm{CO}_{3}\) and \(\mathrm{NH}_{4} \mathrm{NO}_{3}\), (c) \(\mathrm{Na}_{2} \mathrm{~S}\) and \(\mathrm{FeCl}_{3}\)

We will begin by predicting the products formed from the reaction of the given solutions in part (a) \(\mathrm{Ca}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2}\) and \(\mathrm{NaOH}\), part (b) \(\mathrm{K}_{2} \mathrm{CO}_{3}\) and \(\mathrm{NH}_{4} \mathrm{NO}_{3}\), and part (c) \(\mathrm{Na}_{2} \mathrm{~S}\) and \(\mathrm{FeCl}_{3}\). Note that these are double displacement reactions.

Now, we will apply the solubility rules to determine if any of the potential products formed are insoluble (forming a precipitate). (a) Starting with \(\mathrm{Ca}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2}\) and \(\mathrm{NaOH}\): The potential products are: \(\mathrm{Ca(OH)_2}\) and \(\mathrm{Na}\left(\mathrm{CH}_{3} \mathrm{COO}\right)\) Solubility rules: \(\mathrm{Ca(OH)_2}\): calcium hydroxide is considered slightly soluble in water, thus forming a precipitate \(\mathrm{Na}\left(\mathrm{CH}_{3} \mathrm{COO}\right)\): sodium salts are soluble in water The balanced chemical equation is: \[\mathrm{Ca}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2}+2\mathrm{NaOH}\longrightarrow\mathrm{Ca(OH)_2}+\mathrm{2Na}\left(\mathrm{CH}_{3} \mathrm{COO}\right)\] (b) Moving on to \(\mathrm{K}_{2} \mathrm{CO}_{3}\) and \(\mathrm{NH}_{4} \mathrm{NO}_{3}\): The potential products are: \(\mathrm{KNO_3}\) and \(\mathrm{NH_4}\mathrm{(CO_{3})}\) Solubility rules: \(\mathrm{KNO_3}\): potassium salts are soluble in water \(\mathrm{NH_4}\mathrm{(CO_{3})}\): ammonium salts are soluble in water In this case, no precipitation occurs. (c) Finally, \(\mathrm{Na}_{2} \mathrm{S}\) and \(\mathrm{FeCl}_{3}\): The potential products are: \(\mathrm{NaCl}\) and \(\mathrm{FeS}\) Solubility rules: \(\mathrm{NaCl}\): sodium salts are soluble in water \(\mathrm{FeS}\): Metal sulfides, in general are insoluble, including \(\mathrm{FeS}\) which forms a precipitate The balanced chemical equation is: \[\mathrm{2Na}_{2} \mathrm{S}+3\mathrm{FeCl}_{3}\longrightarrow6\mathrm{NaCl}+\mathrm{2FeS}\]

Now we can summarize the results for the given parts: (a) Precipitation occurs, the balanced chemical equation is: \[\mathrm{Ca}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2}+2\mathrm{NaOH}\longrightarrow\mathrm{Ca(OH)_2}+\mathrm{2Na}\left(\mathrm{CH}_{3} \mathrm{COO}\right)\] (b) No precipitation occurs (c) Precipitation occurs, the balanced chemical equation is: \[\mathrm{2Na}_{2} \mathrm{S}+3\mathrm{FeCl}_{3}\longrightarrow6\mathrm{NaCl}+\mathrm{2FeS}\]