An example of a sigma bonded organometallic compound is:

1. Ruthenocene                 

2. Grignard's reagent

3. Ferrocene                     

4. Cobaltocene

The correct order of the stoichiometrics of AgCl formed when AgNO₃ in excess is treated with the complexes:- CoCl₃.6NH₃, CoCl₃.5NH₃, CoCl₃.4NH₃, respectively, is :

1. 1 AgCl, 3 AgCl, 2 AgCl

2. 3 AgCl, 1 AgCl, 2 AgCl

3. 3 AgCl, 2 AgCl, 1 AgCl

4. 2 AgCl, 3AgCl,  1 AgCl

Correct increasing order for the wavelengths of absorption in the visible region for the complexes of Co³⁺ is : 

(1)  $[\mathrm{Co}{\left(\mathrm{en}\right)}_3{]}^{3+}$ , $[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6{]}^{3+}$ , $[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6{]}^{3+}$

(2)  $[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6{]}^{3+}$ , $[\mathrm{Co}{\left(\mathrm{en}\right)}_3{]}^{3+}$, $[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6{]}^{3+}$

(3)  $[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6{]}^{3+}$, $[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6{]}^{3+}$, $[\mathrm{Co}{\left(\mathrm{en}\right)}_3{]}^{3+}$  

(4)  $[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6{]}^{3+}$,$[\mathrm{Co}{\left(\mathrm{en}\right)}_3{]}^{3+}$, $[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6{]}^{3+}$ 

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)

1. dsp²                               

2. sp³

3. d²sp²                             

4. d²sp³

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⁺