Question

The incorrect statement is:
1. The gemstone, ruby, has Cr³⁺ ions occupying the octahedral sites of beryl.
2. The spin-only magnetic moment of [Ni(NH₃)₄ (H₂ O)₂ ]²⁺ is 2.83 BM.
3. The colour of [CoCl(NH₃)₅]²⁺ is violet as it absorbs the yellow light.
4. The spin-only magnetic moments of [Fe(H₂O)₆ ]²⁺ and [Cr(H₂ O)₆ ]²⁺ are nearly similar

Answer 1

Correct Answer - Option 1 : The gemstone, ruby, has Cr³⁺ ions occupying the octahedral sites of beryl.

Concept:

Option (a):

The gemstone, ruby, has Cr³⁺ ions occupying the octahedral sites of Aluminium oxide (Al₂O₃) while beryl is beryllium aluminium cyclosilicate (Be₃ Al₂ Si₆ O₁₈) which is a variety of emerald and aquamarine.

Option (b):

[Ni(NH₃)₄ (H₂O)₂]²⁺ = Ni ²⁺ → 3d⁸ → 2 unpaired electron

Where, μ_m = 2.83 BM

Option (c):

The complimentary colour of violet is yellow.

A colour that combined with a given colour makes white or black is called complimentary colour.

Option (d):

[Fe(H₂O)₆]²⁺, Fe²⁺ → 3d⁶ → 4 unpaired electron

[Cr(H₂O)₆]²⁺, Cr²⁺ → 3d⁴ → 4 unpaired electron

Thus, the spin-only magnetic moments are nearly similar.

Among the given statements, the statement in option (a) is incorrect.