Question

1. when the following solutions are mixed together, what precipitate (if any) will form?

a. feso₄(aq) + kcl(aq)
b. al(no₃)₃(aq) + ba(oh)₂(aq)
c. cacl₂(aq) + na₂so₄(aq)
d. k₂s(aq) + ni(no₃)₂(aq)

Explanation:

Step1: Analyze reaction \(FeSO_{4}(aq)+KCl(aq)\)

Write the potential products by swapping ions: \(FeCl_{2}\) and \(K_{2}SO_{4}\). According to solubility rules, all chlorides (except \(AgCl\), \(PbCl_{2}\), \(Hg_{2}Cl_{2}\)) are soluble and all sulfates (except \(BaSO_{4}\), \(PbSO_{4}\), \(CaSO_{4}\) (slightly soluble), \(SrSO_{4}\)) are soluble. So no precipitate forms.

Step2: Analyze reaction \(Al(NO_{3})_{3}(aq)+Ba(OH)_{2}(aq)\)

Swap ions to get \(Al(OH)_{3}\) and \(Ba(NO_{3})_{2}\). By solubility rules, hydroxides of \(Al^{3 +}\) are insoluble (\(Al(OH)_{3}\) is a precipitate), while \(Ba(NO_{3})_{2}\) is soluble (all nitrates are soluble).

Step3: Analyze reaction \(CaCl_{2}(aq)+Na_{2}SO_{4}(aq)\)

Swap ions: \(CaSO_{4}\) and \(NaCl\). \(NaCl\) is soluble (all sodium salts and chlorides (except some mentioned above) are soluble). \(CaSO_{4}\) is slightly soluble (\(CaSO_{4}\) can be considered as a precipitate in this context as per common precipitation reaction problems).

Step4: Analyze reaction \(K_{2}S(aq)+Ni(NO_{3})_{2}(aq)\)

Swap ions: \(NiS\) and \(KNO_{3}\). \(KNO_{3}\) is soluble (all nitrates and potassium salts are soluble). Sulfides of transition - metal ions (\(Ni^{2+}\)) are insoluble (\(NiS\) is a precipitate).

Answer:

a. No precipitate.
b. \(Al(OH)_{3}\) precipitate.
c. \(CaSO_{4}\) precipitate.
d. \(NiS\) precipitate.