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Mn 3+ / Mn 2+ has large + value because Mn 3+ reduced to Mn +2 which has a half-filled d-orbital configuration ([Ar]4s 0 3d 5 ). On the other hands, Fe 3+ / Fe 2+ has small +ve value because Fe 3+ is much more stable than Fe 2+ . Electronic configuration of Fe 3+ is [Ar]4s 2 3d 5 and Fe 2+ [Ar]4s 2 3d 6 .

Subject

Chemistry

Class

CBSE Class 12

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CBSE Class 12 Chemistry Solved Question Paper 2018

Short Answer Type

11.

Give reasons for the following:

Aquatic animals are more comfortable in the cold water than in warm water.

12.

Give reasons for the following:

Elevation of the boiling point of 1 M KCl solution is nearly double than that of 1 M sugar solution.

13.

Write the formula of the following coordination compound :
Iron(III) hexacyanoferrate (II)

14.

What type of isomerism is exhibited by the complex [Co(NH₃)₅ Cl]SO₄?

15.

Write the hybridisation and number of unpaired electrons in the complex [CoF₆]^3-.

Atomic No. of Co = 27

16.

Identify the chiral molecule in the following pair :

17.
Give reason:
E° value for a Mn³⁺/Mn²⁺ couple is much more positive than that for Fe3⁺/Fe²⁺.

Mn³⁺/ Mn²⁺ has large + value because Mn³⁺ reduced to Mn⁺² which has a half-filled d-orbital configuration ([Ar]4s⁰3d⁵).

On the other hands, Fe³⁺/ Fe²⁺ has small +ve value because Fe³⁺ is much more stable than Fe²⁺. Electronic configuration of Fe³⁺ is [Ar]4s² 3d⁵ and Fe²⁺ [Ar]4s² 3d⁶.