AP EAMCET202021 Sep 2020Evening ShiftChemistryp Block Elements (Group 15, 16, 17 & 18)Actual
A pungent smelling gas (A ) gives dense white fumes with conc. ( HCl ). When (A ) reacts with alkaline solution of a colourless reagent (B ), a reddish-brown precipitate (C ) is formed. The compounds (A, B, C ) respectively are
Options
- A( NO ₂, NaOH , [ Fe ( H ₂ O )₅ NO ]²⁺ )
- B( NH ₃, NaOH , K ₂ Hgl ₄ )
- C( NH ₃, ~K ₂ Hgl ₄, NH ₂, HgO , Hgl )
- D( Cl ₂ ), Sodium nitroprusside, ( [ Na ₂ Fe ( CN )₅ NOS ] )
Correct answer
C. ( NH ₃, ~K ₂ Hgl ₄, NH ₂, HgO , Hgl )
Step-by-step solution
Ammonia gas reacts with hydrogen chloride gas to form dense white fumes of ammonium chloride. This is used as a test to detect the presence of ammonia gas as per the reaction. ( NH ₃(g)+ HCl (g) NH ₄ Cl (s) ) Nessler's reagent is a solution containing ( K ₂ HgI ₄ ) and ( KOH ). lodide and mercury ions react with ammonia under alkaline conditions to produce a reddish brown complex, iodide of million's base ( ( H ₂ ~N - Hg - O - Hg - I ) ) formed. Hence, the correct option is (c).