Question

1. Apurple colour compound A, which is a strong oxidising agent and used for bleaching of wool, cotton, silk and other textile fibres, was added to each of the three test tubes along with \[\ce{H2SO4}\]. It was followed by strong heating.
   
   In which of the above test tubes, A, B or C:
   
   1. Violet vapours will be formed.
   2. The bubbles of gas evolved will extinguish a burning matchstick. Write an equation for each of the above observations.
2. A metal ion \[\ce{M^{n+}}\] of the first transition series having d⁵ configuration combines with three didentate ligands. Assuming Δ₀ < P:
   
   1. Draw the crystal field energy level diagram for the 3d orbital of this complex.
   2. What is the hybridisation of \[\ce{M^{n+}}\] in this complex and why?
   3. Name the type of isomerism exhibited by this complex.

Answer 1

1. 
   
   1. Test tube C:
      \[\ce{10I^- + MnO^-4 + 16 H+ -> 5I2 + 2Mn^{2+} + 8H2O}\]
   2. Test tube A:
      \[\ce{C2O^{2-}4 + 2MnO^-4 + 16H+ -> 10CO2 + 2Mn^{2+} + 8H2O}\]
2.   
   1. 
      
   2. Sp³d², Since Δ₀ > P, it will form an outer orbital complex as the electrons in the 3d orbital will not pair up. 
   3. Optical isomerism.