$CuS{O}_4$ decolourises on addition of excess KCN, the product is-

1. ${\left[Cu{\left(CN\right)}_4\right]}^{2-}$

2. ${\left[Cu{\left(CN\right)}_4\right]}^{3-}$

3. $Cu{\left(CN\right)}_2$

4. CuCN

If the bond length of CO bond in carbon monoxide is 1.128 $\stackrel{0}{A}$, then what is the value of CO bond length is $Fe{\left(CO\right)}_5$ ?

1. 1.15 $\stackrel{0}{A}$

2. 1.128 $\stackrel{0}{A}$

3. 1.72 $\stackrel{0}{A}$

4. 1.118 $\stackrel{0}{A}$

Among the following metal carbonyls, the C-O bond order is lowest in

1. ${\left[Mn{\left(CO\right)}_6\right]}^{+}$

2. $\left[Fe{\left(CO\right)}_5\right]$

3. $\left[Cr{\left(CO\right)}_6\right]$

4. ${\left[V{\left(CO\right)}_6\right]}^{-}$

Geometrical shapes of the complexes formed by the reaction of $N{i}^{2+} with C{l}^{-}, C{N}^{-} and H_{2}O$ respectively, are

1. Octahedral, tetrahedral and square planar

2. Tetrahedral, square planar and octahedral

3. Square planar, tetrahedral and octahedral

4. Octahedral, square planar and octahedral

The volume (in mL) of 0.1 M AgNO₃ required for complete precipitation of chloride ions present in 30 mL of 0.01 M solution of [Cr(H₂O)₅Cl]Cl₂, as silver chloride is close to

1. 4

2. 6

3. 20

4. 60

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)