Chemistry - Co-ordination Compounds Question with Solution | TestHub

${\left[\mathrm{Ni}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}_{(\mathrm{aq})}^{+2}+{\mathrm{en}}_{(\mathrm{aq})}\to {\left[\mathrm{Ni}{\left({\mathrm{H}}_2\mathrm{O}\right)}_4(\mathrm{en})\right]}_{(\mathrm{aq})}^{+2}+2{\mathrm{H}}_2\mathrm{O}$

Green
${\left[\mathrm{Ni}{\left({\mathrm{H}}_2\mathrm{O}\right)}_4(\mathrm{en})\right]}_{(\mathrm{aq})}^{+2}+{\mathrm{en}}_{(\mathrm{aq})}\to {\left[\mathrm{Ni}{\left({\mathrm{H}}_2\mathrm{O}\right)}_2(\mathrm{en}{)}_2\right]}_{(\mathrm{aq})}^{+2}+2{\mathrm{H}}_2\mathrm{O}$

Pale Blue
${\left[\mathrm{Ni}{\left({\mathrm{H}}_2\mathrm{O}\right)}_2(\mathrm{en})\right]}_{(\mathrm{aq})}^{+2}+{\mathrm{en}}_{(\mathrm{aq})}\to {\left[\mathrm{Ni}(\mathrm{en}{)}_3\right]}_{(\mathrm{aq})}^{+2}+2{\mathrm{H}}_2\mathrm{O}$

Blue / purple