CrO₄^2- and MnO₄^- are strong yellow and intense purple  respectively in aqueous solution The darkening of colour is due to

1. charge transfer

2. d-d transition

3. half-filled d-sub shells

4. increasing number of unpaired electron

In the dichromate ion Cr₂O₇^2-,

1. 4 Cr-O bonds are equivalent

2. 6 Cr-O bonds are equivalent

3. All Cr-O bonds are equivalent

4. None of Cr-O bonds are equivalent

The electronic configuration of a transition element X in +3 Oxidation state is [Ar]3d⁵.

The atomic number of X is :

1. 25

2. 26

3. 27

4. 24

Magnetic moment of K₃[Fe(CN)₅(H₂O)] is

1. 0

2. 4.92

3. 3.87

4. 2.83

Which is colorless in water?

1. Ti³⁺

2. V³⁺

3. Cr³⁺

4. Sc³⁺

From the following, which is the most basic hydroxide?

1. Ce(OH)₃

2. Lu(OH)₃

3. Yb(OH)₃

4. Tb(OH)₃

Name the gas that can readily decolourise acidified KMnO₄ solution.

(1) CO₂           

(2) SO₂           

(3) NO₂             

(4) P₂O₅

HgCl₂ and I₂ both when dissolved in water containing I^- ions the pair of species formed is

(a) HgI₂, ${\mathrm{I}}_3^{-}$                              (b) HgI₂, I^-

(c) ${\mathrm{HgI}}_4^{2-}, {\mathrm{I}}_3^{-}$                             (d) Hg₂I₂, I^-

The incorrect statement regarding the lanthanons is ;

Which one of the following statements is correct when SO₂ is passed through acidified

K₂Cr₂O₇ solution?

1. The solution is decolourized

2. SO₂ is reduced

3. Green Cr₂(SO₄)₃ is formed

4. The solution turns blue