Coordination Compounds · JEE Advanced previous year questions

2025 2 questions

1. Q342025 · 18 May 2025 · Paper 1

   The correct order of the wavelength maxima of the absorption band in the ultraviolet-visible region for the given complexes is

   1. A.$[\mathrm{Co}(\mathrm{CN}{)}_6{]}^{3-}<[\mathrm{Co}(\mathrm{N}{\mathrm{H}}_3{)}_6{]}^{3+}<[\mathrm{Co}(\mathrm{N}{\mathrm{H}}_3{)}_5({\mathrm{H}}_2\mathrm{O}){]}^{3+}<[\mathrm{Co}(\mathrm{N}{\mathrm{H}}_3{)}_5(\mathrm{Cl}){]}^{2+}$
   2. B.$[\mathrm{Co}(\mathrm{N}{\mathrm{H}}_3{)}_5(\mathrm{Cl}){]}^{2+}<[\mathrm{Co}(\mathrm{N}{\mathrm{H}}_3{)}_5({\mathrm{H}}_2\mathrm{O}){]}^{3+}<[\mathrm{Co}(\mathrm{N}{\mathrm{H}}_3{)}_6{]}^{3+}<[\mathrm{Co}(\mathrm{CN}{)}_6{]}^{3-}$
   3. C.$[\mathrm{Co}(\mathrm{CN}{)}_6{]}^{3-}<[\mathrm{Co}(\mathrm{N}{\mathrm{H}}_3{)}_5(\mathrm{Cl}){]}^{2+}<[\mathrm{Co}(\mathrm{N}{\mathrm{H}}_3{)}_5({\mathrm{H}}_2\mathrm{O}){]}^{3+}<[\mathrm{Co}(\mathrm{N}{\mathrm{H}}_3{)}_6{]}^{3+}$
   4. D.$[\mathrm{Co}(\mathrm{N}{\mathrm{H}}_3{)}_6{]}^{3+}<[\mathrm{Co}(\mathrm{CN}{)}_6{]}^{3-}<[\mathrm{Co}(\mathrm{N}{\mathrm{H}}_3{)}_5(\mathrm{Cl}){]}^{2+}<[\mathrm{Co}(\mathrm{N}{\mathrm{H}}_3{)}_5({\mathrm{H}}_2\mathrm{O}){]}^{3+}$
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   Answer: A

2. Q332025 · 18 May 2025 · Paper 2

   During sodium nitroprusside test of sulphide ion in an aqueous solution, one of the ligands coordinated to the metal ion is converted to

   1. A.$\mathrm{NO}{\mathrm{S}}^{-}$
   2. B.$\mathrm{SC}{\mathrm{N}}^{-}$
   3. C.$\mathrm{SN}{\mathrm{O}}^{-}$
   4. D.$\mathrm{NC}{\mathrm{S}}^{-}$
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   Answer: A