Which of the following metal ions is not coloured?

• Ti³⁺

• Fe³⁺

• V²⁺

• Zn²⁺

The lanthanide contraction is responsible for the fact that

• Zr and Zn have the same oxidation state

• Zr and Hf have about the same radius

• Zr and Nb have similar oxidation state

• Zr and Y have about the same radius

The correct order of ionic radii of Y³⁺, La³⁺, Eu³⁺ and Lu³⁺ is

(Atomic no. Y = 39, La = 57, Eu = 63, Lu = 71)

• Lu³⁺ < Eu³⁺ < La³⁺ < Y³⁺

• La³⁺ < Eu³⁺ < Lu³⁺ < Y³⁺

• Y³⁺ < La³⁺ < Eu³⁺ < Lu³⁺

• Y³⁺  < Lu³⁺ < Eu³⁺ < La³⁺

Green vitriol is:

• FeSO₄·7H₂O

• ZnSO₄·7H₂O

• CuSO₄·5H₂O

• CuSO₄·1/2H₂O

When copper sulphate solution is added to potassium ferrocyanide, the formula of product obtained is

• Cu₂Fe(CN)₆

• Cu(CN)₃

• CuFe(CN)₆

• Cu(CN)₂

Formation of coloured ions by transition metals signifies;

• absorption of light from UV range

• emission of light

• presence of unparied electrons in s and p orbitals

• complimentary colours to the absorbed light

Transition metal ions show colour because

• they absorb light

• They emit light

• They are paramagentic

• they exhibit d-d transition

Transitional metal ions have an ability of complex formation. They have this tendency due to

• catalytic property

• high enthalpy of atomisation

• high nuclear charge

• All of the above

549.

In the reduction of KMnO₄ by warm acidified oxalic acid, the oxidation number of Mn changes from

• +4 to +2

• +6 to +4

• +7 to +2

• +7 to +4

Transition metals have the electronic configuration (n -1)d^1-10ns^1-2. The d-orbitals are degenerate. Colour of transition metal ions is due to absorption of some wavelength. This result is

• d-s transition

• s-d transition

• s-s transition

• d-d transition