Question

When hydrated ammonium iron(III) is dissolved in water and acidified barium chloride solution is added, what observation is seen?

a) Formation of a white precipitate
b) Release of gas bubbles
c) Color change to green
d) No observable change

Answer 1

The correct observation when acidified barium chloride is added to a hydrated ammonium iron(III) sulfate solution is the formation of a white precipitate, which is barium sulfate.

Step-by-step explanation:

When hydrated ammonium iron(III) sulfate is dissolved in water and acidified barium chloride solution is added, the likely observation is the formation of a white precipitate. This reaction occurs because barium ions (Ba2+) from the barium chloride react with sulfate ions (SO42-) from the iron(III) sulfate to form barium sulfate (BaSO4), which is a white, insoluble solid. This process is demonstrated in the following chemical reaction:

BaCl2(aq) + Fe2(SO4)3(aq) → 2BaSO4(s) + FeCl3(aq)

The barium sulfate precipitate does not dissolve in water or acids, such as hydrochloric acid, which helps to confirm its identity. Given the information presented, the correct observation when adding the acidified barium chloride solution to the ammonium iron(III) sulfate solution is option (a) the formation of a white precipitate. This is a classic test for the presence of sulfate ions in a solution.