Correct increasing order for the wavelengths of absorption in the visible region for the complexes of \(\text{Co}^{3+}\) is:

1.	\(\left[\mathrm{Co}(\mathrm{en})_3\right]^{3+}<\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}<\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}\)
2.	\(\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}<\left[\mathrm{Co}(\mathrm{en})_3\right]^{3+}<\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}\)
3.	\(\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}<\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}<\left[\mathrm{Co}(\mathrm{en})_3\right]^{3+}\)
4.	\(\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}<\left[\mathrm{Co}(\mathrm{en})_3\right]^{3+}<\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}\)

Jahn-Teller effect is not observed in high spin complexes of

1. d⁷

2. d⁸

3. d⁴

4. d⁹

Which of the following has longest C-O bond length? (Free C-O bond length in CO is

1.128 Å.)

1. [Co(СО)₄]^-

2. [Fe(CO)₄]^2-

3. [Mn(CO)₆]⁺

4. Ni(CO)₄

Which of the following statements is false?

1. Ca²⁺ ions are important in blood clotting

2. Ca²⁺ ions are not important in maintaining the regular beating of the heart

3. Mg²⁺ ions are important in the green parts of plants

4. Mg²⁺ ions form a complex with ATP

The correct statement among the following about [Co(CN)₆]^3- is :

The total number of possible isomers for the complex [Co(en)₂Cl₂]Cl are:
[en-ethylenediamine]

1. 2                         

2. 1

3. 3                         

4. 4

The hybridisation of Ni in the complex [Ni(CN)₄]^2- is:
(Atomic number of Ni = 28)

The sum of coordination number and oxidation number of the metal M in the complex M(en)₂(C₂O₄)]Cl (where, en is ethylenediamine) is : 

1. 9

2. 6

3. 7

4. 8

The name of complex ion, [Fe(CN)₆]^3- is :-

1. hexacyanoiron (III) ion

2. hexacyanitoferrate (III) ion

3. tricyanoferrate (III) ion

4. hexacyanidoferrate (III)ion

Among the following complexes, the one which shows zero crystal field stabilisation

energy (CFSE) is:-

1. [Mn(H₂O)6]³⁺

2. [Fe(H₂O)6]³⁺

3. [Co(H₂O)6]²⁺

4. [Co(H₂O)6]³⁺