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A solution of [Ni(H(2)O)(6)]^(2+) is gre...

A solution of `[Ni(H_(2)O)_(6)]^(2+)` is green but a solution of `[Ni(CN)_(4)]^(2-)` is colourless Explain.

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In `[Ni(H_(2)O_(2))_(6)]^(2+)`. Ni is in +2 state with the configuration `3d^(8)` i.e., it has two unpaired electrons which do not pair up in the presence of the weak `H_(2)O` ligand. Hence, it is coloured. The d-d transition, absorbs red light and the complementary light emitted is green
In case of `[Ni(CN)_(4)]^(2-)` Ni is again in +2 state with the configuration `3d^(@)` but in presence of the strong CN ligand, the two unpaired electrons in the 3d orbitals pair up. Thus, there is no unpaired electron present. Hence, it is colourless
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Assertion A solution of [Ni(H_(2)O)_(6)]^(2+) is green but a solution of [Ni(CN)_(4)]^(2+) is colourless Reason [Ni(CN)_(4)]^(2+) is square planar complex .

(i) What type of isomerism is shown by the complex [Co(NH_(3))_(6)] [Cr(CN)_(6))] ? (ii) Why a solution of [Ni(H_(2)O)_(6)^(2+) is given while a solution of [No(CN)_(4)]^(2-) colourless ? (At. No. of Ni = 28) (iii) Write the IUPAC name of the following complex : [Co(NH_(3))_(5) (CO_(3))] Cl

The complex ion [Ni(CN)_4]^(2-) is :

The IUPAC name of [Ni(CN)_(4)]^(2-) is

The hexaaqua complex [Ni(H_(2)O)_(6)]^(2+) is green, whereas the corresponding ammonia complex [Ni(NH_(3))_(6)]^(2+) is violet. Explain.

[Ti(H_2O)_6]^(3+) is coloured while [Sc(H_2O)_6]^(3+) is colourless . Explain.

Assertion: [Ti(H_(2)O)_(6)]^(4+) is coloured while [Sc(H_(2)O)_(6)]^(3+) is colourless. Reason: d-d transition is not possible in [Sc(H_(2)O)_(6)]^(3+) .

Explain the following giving reasons [NiCI_(4)]^(2-) is tetrahedral and paramagnetic whereas [Ni(CN)_(4)]^(2-) is square plannar and dimagnetic.

(a). Why Mn^(2+) compounds are more stable than Fe^(2+) towards oxidation to their +3 state? (b). Calculate the magnetic moment of V^(3+) ion. (c). [Ti(H_2O)_6_^(3+) gives violet coloured aqueous solution but [Mg(H_2O)_6]^(2+) solution is colourless. (d). [Ti(H_2O)_6]^(3+) is coloured whereas [Sc(H_2O)_6]^(3+) is colourless. Why?

[Cr(NH_3)_6]^(3+) is paramagnetic while [Ni(CN)_4]^(2-) is diamagnetic. Explain why?