NiCl₂{P(C₂H₅)₂(C₆H₅)}₂ exhibits temperature dependent magnetic behaviour (paramagnetic/diamagnetic). The coordination geometries of $N{i}^{2+}$ in the paramagnetic and diamagnetic states are respectively:

1. Tetrahedral and tetrahedral

2. square planar and square planar

3. Tetrahedral and square planar

4. Square planar and tetrahedral

Consider the following complex ions P, Q and R,

P = ${\left[{\mathrm{FeF}}_6\right]}^{3-}$

Q = ${\left[\mathrm{V}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{2+}$

and R= ${\left[\mathrm{Fe}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{2+}$

The correct order of the complex ions, according to their spin-only magnetic moment values (in B.M.) is

1. R<Q<P

2. Q<R<P

3. R<P<Q

4. Q<P<R

In the complexes [Fe(H₂O)₆]³⁺, [Fe(SCN)₆]^3-, [Fe(C₂O₄)3]^3- and [FeCl₆]^3-, more stability is shown by

1. [Fe(H₂O₆]³⁺

2. $[Fe{\left(SCN\right)}_6{]}^{-3}$

3 [Fe(C₂O₄)₃]^3-

4. [FeCl₆]^3-

Ammonia forms the complex ion [Cu(NH₃)₄]²⁺ with copper ions in alkaline solutions but not in acidic solution. What is the reason for it?

1. In acidic solutions hydration protects copper ions

2. In acidic solutions protons coordinate with ammonia molecules forming ions and $N{H}_3$ molecules are not available

3. In alkaline solutions insoluble $Cu{\left(OH\right)}_2$ is precipitated which is soluble in excess of any alkali

4. Copper hydroxide is an amphoteric substance

For octahedral complex, the value of the 'spin only' magnetic moment for one of the following configuration is 2.84 BM. The correct one is

1. d⁴ (in strong ligand field)

2. d⁴ (in weak ligand field)

3. d³ (in weak as well as in strong field)

4. d⁵ (in strong ligand field)

In Fe (CO)₅, the Fe-C bond possesses

1. ionic character

2. $\sigma$-character only

3. $\pi$-character only

4. both $\sigma$ and $\pi$ character

Which of the following pairs represents linkage isomers?

1. [Co(NH₃)₅NO₃]SO₄ and [Co(NH₃)₅SO₄]NO₃

2. [PtCl₂)(NH₃)₄]Br₂ and [PtBr₂(NH₃)₄]Cl₂

3. [Cu(NH₃)₄[PtCl₄] and [Pt(NH₃)₄][CuCl₄]

4. [Pd(PPh₃)₂(NCS)₂ and [Pt(PPh₃)₂(SCN)₂]

A solution containing 2.675 g of CoCl₃.6NH₃ (molar mass=267.5 g mol-1) is passed through a cation exhanger. The chloride ions obtained in solution were treated with excess of AgNO₃ to give 4.78 g of AgCl (molar mass = 143.5 g mol-1). The formula of the complex is
(At. mass of Ag = 108 u)

1. [CoCl(NH₃)₅]Cl₂

2. [Co(NH₃)₆Cl₃

3. [CoCl₂(NH₃)₄]Cl

4. [CoCl₃(NH₃)₃]

Which of the following facts about the complex [Cr(NH₃)₆]Cl₃ is wrong?