IAS Chemistry Questions (Read 5 times)

1. A black colored compd A on reaction with dil H2SO4 gives a gas B which on passing in a soln of an acid C gives a white turbidity D. Gas B when passed thro acidified soln of E gives a ppt F solution in dil HNO3. After boiling this soln when an excess of ammonium hydroxide is added a blue colored compd G is formed. To this soln on addn of acetic acid and aq pot ferrocyanide a chocolate ppt H is obtained. On addn of an aq soln of Ea white ppt insol in HNO 3 is obtained. Identify A to H.

2. A mix of 2 salts were treated as follows:

   1. The mix was heated with manganese dioxide and conc H2SO4 when yellowish green gas was obtained.
   2. The mix on heating with sod hydroxide soln gave a gas, which turned red litmus blue.
   3. Its soln in water gave blue ppt with pot ferricyanide and red coloration with amm thiocyanate.
   4. The mix was boiled with pot hydroxide and the liberated gas was bubbled thro an alk soln of K2HgI4 to give brown pt.

Identify the 2 salts. Give ionic reactions for the tests (i) to (iii).