Question

FILL IN THE BLANKS :

1. If the ions of group III are precipitated by NH₄Cl and NH₄OH without prior oxidation by conc.HNO₃ _________ is not completely precipitated. 
2. The soluble Prussian blue has chemical composition ___________ . 
3. Solution of a salt in conc.HCl is blue, but turns pink on dilution. It indicates the presence of _______ radical. 
4. Dimethyl glyoxime in alkaline medium is used for the identification of _________ and _________ radicals. 
5. Manganese ion (Mn²⁺) gives _____________ coloured borax bead in oxidising flame in cold. 
6. Ammonium thiocyanate is used in detection of ______________ and ______________ . 
7. A salt “X” gives apple green colour in Bunsen flame and also gives brown fumes on reaction with dil. H₂SO₄. The salt “X” is ___________. 

Answer 1

1. Fe²⁺ (ferrous ion) 
2. KFe[Fe(CN)₆]
3. Cobalt (Co²⁺) 
4. Ni²⁺, Fe²⁺ 
5. Red
6. Co²⁺ and Fe³⁺ or Hg²⁺ ions
7. Ba(NO₂)₂