Question

Which of the following arrangements does not represent
the correct order of the property stated against it ?
(a) V²⁺ < Cr²⁺ < Mn²⁺ < Fe²⁺ : paramagnetic behaviour
(b) Ni²⁺ < Co²⁺ < Fe²⁺ < Mn²⁺ : ionic size
(c) Co³⁺ < Fe³⁺ < Cr³⁺ < Sc³⁺ : stability in aqueous solution
(d) Sc < Ti < Cr < Mn : number of oxidation states

Answer 1

Correct option (a) V2+ < Cr2+ < Mn2+ < Fe2+: paramagnetic behaviour

Answer 2

the correct order of the property stated against it is  (a) V²⁺ < Cr²⁺ < Mn²⁺ < Fe²⁺ : paramagnetic behaviour

1. Para magnetic property is due to the number of unpaired electrons.
2. More the number of unpaired electrons unpaired electron more the  paramagnetism
3. Firstly the number of unpaired electron V²⁺ and Cr²⁺ is same n=3
4. Secondly the number of unpaired electron in Mn²⁺ n= 5 and  in Fe²⁺ n=4
5. So the correct order for  above para magnetic behaviour is
6. V²⁺ = Cr²⁺ < Fe²⁺ < Mn²⁺