The correct order for the wavelengths of absorption in the visible region for the following is:
\(\left[\mathrm{Ni}\left(\mathrm{NO}_2\right)_6\right]^{4-},\left[\mathrm{Ni}\left(\mathrm{NH}_3\right)_6\right]^{2+},\left[\mathrm{Ni}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\)
1. $[\mathrm{Ni}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6{]}^{2+}$ < $[\mathrm{Ni}{\left({\mathrm{NH}}_3\right)}_6{]}^{2+}$ < $[\mathrm{Ni}{\left({\mathrm{NO}}_2\right)}_6{]}^{4-}$

2. $[\mathrm{Ni}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6{]}^{2+}$ > $[\mathrm{Ni}{\left({\mathrm{NH}}_3\right)}_6{]}^{2+}$ > $[\mathrm{Ni}{\left({\mathrm{NO}}_2\right)}_6{]}^{4-}$

3. $[\mathrm{Ni}{\left({\mathrm{NH}}_3\right)}_6{]}^{2+}$ > $[\mathrm{Ni}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6{]}^{2+}$ > $[\mathrm{Ni}{\left({\mathrm{NO}}_2\right)}_6{]}^{4-}$

4.  $[\mathrm{Ni}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6{]}^{2+}$ > ${\left[\mathrm{Ni}{\left({\mathrm{NO}}_2\right)}_6\right]}^{4-}$ > [Ni(NH₃)₆]²⁺

The number of unpaired electrons in the following complexes respectively are-

${\mathrm{K}}_4\left[\mathrm{Mn}{\left(\mathrm{CN}\right)}_6\right], \mathrm{Fe}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6{]}^{2+}, {\mathrm{K}}_2\left[{\mathrm{MnCl}}_4\right]$

1. 1, 4, 5

2. 2, 4, 5

3. 0, 3, 4

4. 2, 3, 4

Match Column-I with Column-II and mark the correct option.

Codes:
1. i=d, ii=c, iii=b, iv=a

2. i=c, ii=d, iii=b, iv=a

3. i=c, ii=d, iii=a, iv=b

4. i=a, ii=c, iii=b, iv=d

The correct representation of tetrahydroxidozincate (II) is:
1. \([Zn(OH)_4]^{2-}\)
2. \([Zn(OH)_4]^{-}\)
3. \([Zn(OH)_4]^{3-}\)
4. \([Zn(OH)_4]\)

$1.$ ${\mathrm{K}}_2\left[\mathrm{Cr}{\left({\mathrm{C}}_2{\mathrm{O}}_4\right)}_3\right]$
$2.$ ${\mathrm{K}}_3\left[\mathrm{Cr}{\left({\mathrm{C}}_2{\mathrm{O}}_4\right)}_3\right]$
$3.$ ${\mathrm{K}}_3\left[\mathrm{Cr}{\left({\mathrm{C}}_2{\mathrm{O}}_4\right)}_2\right]$
$4.$ ${\mathrm{K}}_2\left[\mathrm{Cr}{\left({\mathrm{C}}_2{\mathrm{O}}_4\right)}_4\right]$

The correct representation of pentaamminenitrito-O-cobalt(III) is :

$1. {\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_5\left(\mathrm{ONO}\right)\right]}^{3+}$
$2. {\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_5\left(\mathrm{ONO}\right)\right]}^{2+}$
$3. {\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_5\left(\mathrm{ONO}\right)\right]}^{2-}$
$4. {\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_5\left(\mathrm{ONO}\right)\right]}^{3-}$

The correct representation of potassium tetracyanidonickelate(II) is :

$1. {\mathrm{K}}_3\left[\mathrm{Ni}{\left(\mathrm{CN}\right)}_4\right]$
$2. \mathrm{K}\left[\mathrm{Ni}{\left(\mathrm{CN}\right)}_4\right]$
$3. {\mathrm{K}}_2\left[\mathrm{Ni}{\left(\mathrm{CN}\right)}_4\right]$
$4. {\mathrm{K}}_2\left[\mathrm{Ni}{\left(\mathrm{CN}\right)}_5\right]$

The correct splitting diagram of d orbitals in an octahedral crystal field is:

1.		2.
3.		4.	None of these.

The ligand(s)that show a chelating effect is/are: