A solution contains one or more of the following ions: Hg2+2, Ba2+, and Fe2+. When potassium chloride is added to the solution, a precipitate forms. The precipitate is filtered off and potassium sulfate is added to the remaining solution, producing no precipitate. When potassium carbonate is added to the remaining solution, a precipitate forms.

Write net ionic equations for the formation of each of the precipitates observed.
Express your answers as chemical equations separated by a comma. Identify all of the phases in your answer.

Question

A solution contains one or more of the following ions: Hg2+2, Ba2+, and Fe2+. When potassium chloride is added to the solution, a precipitate forms. The precipitate is filtered off and potassium sulfate is added to the remaining solution, producing no precipitate. When potassium carbonate is added to the remaining solution, a precipitate forms.

Write net ionic equations for the formation of each of the precipitates observed.
Express your answers as chemical equations separated by a comma. Identify all of the phases in your answer.

anonymous · Answer

Alright then. The most likely ions to react with Cl- is either Barium or Iron. To make sure which will react, you have to check on the electropositivity of the 2 ions and the most electropositive is barium. Remember, the greater the difference of positivity and negativity, the greater the attraction. Hence:
KCl + Ba2+ - BaCl2 (precipitate) + K+
Secondly, you will have Fe2+ + K2SO4 - FeSO4 + K+, forming a pale green solution, rather than a precipitate.
Finally, K2CO3 + Hg2+ might remain as it is, because mercurium cannot displacempotassium and hence, the  solid/precipitate remains in the solution.