Question

Rita was given an unknown salt for identification. She prepared a solution of the salt and divided it into two parts.

• To the first part of the salt solution, she added a few drops of ammonium hydroxide and obtained a reddish-brown precipitate.
• To the second part of the salt solution, she added a few drops of silver nitrate solution and obtained a white precipitate.

Name:

1. The cation present and
2. The anion present in the salt given for identification.

Answer 1

1. Cation \[\ce{Fe^3+}\] (ferric ion)
   When \[\ce{Fe^3+}\] reacts with \[\ce{NH4OH}\] it forms ferric hydroxide.
   
   \[\ce{Fe^{3+} + 3NH4OH -> \underset{(Reddish brown ppt.)}{Fe(OH)3 + 3NH4^+}}\]
2. Anion: \[\ce{Cl−}\] (Chloride ion)
   When \[\ce{Cl−}\] reacts with silver nitrate, it forms a white ppt. of silver chloride.
   
   \[\ce{Cl- + AgNO3 - \underset{Silver chloride}{AgCl + NO^-3}}\]