Which of the following arrangements does not represent the c... | CHEMISTRY - GENERAL PROPERTIES OF THE TRANSITION ELEMENTS (D-BLOCK) | SolveeIt | Solveeit

Today, August 19

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

V2+< Cr2+<Mn2+< Fe2+ : paramagnetic behaviour

Explanation

Solution

(1) V2+ = 3 unpaired electrons

Cr2+ = 4 unpaired electrons

Mn2+ = 5 unpaired electrons

Fe2+ = 4 unpaired electrons

Hence the order of paramagnetic behaviour should be

V2+ < Cr2+ = Fe2+ < Mn2+

(2) ionic size decrease from left to right in same period.

(3) As per data from NCERT.

Co3+ /Co2+= 1.97 ; Fe3+/Fe2+ =0.77 ; Cr3+ /Cr2+= - 0.41

Sc3+ is highly stable (It does not show +2)

(4) The oxidation states increases as we go from group 3 to group 7 in same period.