When the following solutions are mixed together, what precipitate (if any) will form? a. \(\mathrm{FeSO}_{4}(a q)+\mathrm{KCl}(a q)\) b. $\mathrm{Al}\left(\mathrm{NO}_{3}\right)_{3}(a q)+\mathrm{Ba}(\mathrm{OH})_{2}(a q)$ c. \(\mathrm{CaCl}_{2}(a q)+\mathrm{Na}_{2} \mathrm{SO}_{4}(a q)\) d. $\mathrm{K}_{2} \mathrm{S}(a q)+\mathrm{Ni}\left(\mathrm{NO}_{3}\right)_{2}(a q)$

For each reaction, we'll be mixing two ionic compounds in aqueous solutions which will undergo a double displacement reaction. Their cations and anions will be exchanged.

Cations: \(\mathrm{Fe}^{2+}, \mathrm{K}^+\) Anions: \(\mathrm{SO}_4^{2-}, \mathrm{Cl}^-\) Possible products: FeCl\(_{2}\) and K\(_{2}\)SO\(_{4}\)

Cations: \(\mathrm{Al}^{3+}, \mathrm{Ba}^{2+}\) Anions: \(\mathrm{NO}_3^-, \mathrm{OH}^-\) Possible products: Al(OH)\(_{3}\) and Ba(NO\(_{3}\))\(_{2}\)

Cations: \(\mathrm{Ca}^{2+}, \mathrm{Na}^+\) Anions: \(\mathrm{Cl}^-, \mathrm{SO}_4^{2-}\) Possible products: CaSO\(_{4}\) and NaCl

Cations: \(\mathrm{K}^+, \mathrm{Ni}^{2+}\) Anions: \(\mathrm{S}^{2-}, \mathrm{NO}_3^-\) Possible products: KNO\(_{3}\) and NiS Now, we will check the solubility of these possible products.

We'll use the solubility rules to determine if any of the products formed are insoluble and result in the formation of a precipitate. 1. FeCl\(_{2}\) and K\(_{2}\)SO\(_{4}\): Chlorides and sulfates are generally soluble. No precipitate will form in this case. 2. Al(OH)\(_{3}\) and Ba(NO\(_{3}\))\(_{2}\): Hydroxides are generally insoluble except for Group I elements and some Group II elements (Ca, Sr, Ba). Al(OH)\(_{3}\) is insoluble and will form a precipitate. Ba(NO\(_{3}\))\(_{2}\) is soluble. 3. CaSO\(_{4}\) and NaCl: Sulfates are generally soluble, but CaSO\(_{4}\) is an exception and is moderately soluble. In this situation, it will form a precipitate. NaCl is soluble. 4. KNO\(_{3}\) and NiS: Nitrates are soluble. KNO\(_{3}\) is soluble and Sulfides are generally insoluble except for Group I, II, and NH\(_{4}^+\). NiS is insoluble and will form a precipitate.

The following are the precipitates formed in each reaction: a. No precipitate b. Al(OH)\(_{3}\) c. CaSO\(_{4}\) d. NiS After mixing the given solutions, the precipitates formed are Al(OH)\(_{3}\), CaSO\(_{4}\), and NiS.