Verified Solution • 2025–26 Session moderate

QAIPMT-2005-Ch-2504: NEET 2005 Chemistry - Class 12 AIPMT-2005-Ch-2504 Solution: The aqueous solution containing which one of the following ions …

The aqueous solution containing which one of the following ions will be colourless? (Atomic number: Sc = 21, Fe = 26, Ti = 22, Mn = 25)

Multiple Choice Options

A $Ti^{3+}$
B $Mn^{2+}$
C $Sc^{3+}$
D $Fe^{2+}$

Step-by-Step Verified Solution

If the transition metal ion has unpaired electron then it shows colour. Sc 3+ : [Ar] 18 3d 0 4s 0 Fe 2+ : [Ar] 18 3d 5 4s 1 Ti 3+ : [Ar] 18 3d 1 4s 0 Mn 2+ : [Ar] 18 3d 5 4s 0 Hence, Sc 3+ do not contain unpaired electron and hence it will not undergo d � d transition and do not show colour.

Related Learning Resources & Exam Preparation

NEET PYQ Question Bank

Browse year-wise authentic previous years' questions with solutions

Authentic CBT Mock Tests

Simulate official exam environment with live timer and percentile scoring