TRUE OR FALSE :
1. In a solution containing Fe3+ and Mg2+ ions, selective precipitation of Fe(OH)3 is done by aqueous ammonia in presence of NH4Cl.
2. Colour of chromium hydroxide (green) turns yellow on dissolving in NaOH solution in the presence of H2O2.
3. Sr2+ ions in very dilute solution do not give yellow precipitate with CrO42 ions.
Hint : SrCrO4 is appreciable soluble in water.
4. Ca2+ ions give yellow precipitate in presence of ammonia with potassium ferrocyanide solution.
Hint : White precipitate of K(NH4)Ca[Fe(CN)6]
5. Mg2+ ions in solution gives gelatinous white precipitate of magnesium hydroxide with ammonia solution and the precipitate is readily soluble in solutions of ammonium salts.
Hint : Mg2+ + 2NH3 + 2H2O ⇄ Mg(OH)2 ↓ + 2NH4+