Question

why the solution is made alkaline with Ammonia in the limit of test of iron​

Answer 1

Answer:

Ferrous thioglycollate complex is colorless in acidic or neutral solutions. Only in the presence of alkali pale pink color will be produced. citric acid forms ammonium citrate buffer when ammonia is added to make alkaline which in turn stabilizes the complex formed.

Answer 2

Explanation:

Ferrous thioglycollate complex is colorless in acidic or neutral solutions. Only in the presence of alkali pale pink color will be produced. citric acid forms ammonium citrate buffer when ammonia is added to make alkaline which in turn stabilizes the complex formed.