The correct order of intensity of colors of the compounds is:

1. ${\left[\mathrm{Ni}(\mathrm{CN}{)}_4\right]}^{2-}>{\left[{\mathrm{NiCl}}_4\right]}^{2-}>{\left[\mathrm{Ni}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{2+}$
2. ${\left[\mathrm{Ni}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{2+}>{\left[{\mathrm{NiCl}}_4\right]}^{2-}>{\left[\mathrm{Ni}(\mathrm{CN}{)}_4\right]}^{2-}$
3. ${\left[{\mathrm{NiCl}}_4\right]}^{2-}>{\left[\mathrm{Ni}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{2+}>{\left[\mathrm{Ni}(\mathrm{CN}{)}_4\right]}^{2-}$
4. ${\left[{\mathrm{NiCl}}_4\right]}^{2-}>{\left[\mathrm{Ni}(\mathrm{CN}{)}_4\right]}^{2-}>{\left[\mathrm{Ni}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{2+}$

Solution

Asked in: JEE Main 2021 (20 Jul Shift 1)

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