Question

Calculate the magnetic moment of a divalent ion in aqueous medium if its atomic number is 25

• A. √27
• B. √37
• C. √35
• D. √25

Answer 1

The Correct Option is C

To calculate the magnetic moment of a divalent ion with atomic number 25 (manganese, Mn), we follow these steps:

Step 1: Determine the electronic configuration of manganese. The atomic number is 25, so the electronic configuration is:

Mn: [Ar] 3d⁵ 4s²

Step 2: Account for the divalent state (Mn²⁺). The loss of two electrons occurs from the 4s and 3d orbitals:

Mn²⁺: [Ar] 3d⁵

Step 3: Calculate the number of unpaired electrons. In the 3d⁵ configuration, all five electrons are unpaired.

Step 4: Use the formula for magnetic moment (μ):

μ = √(n(n+2))

where n is the number of unpaired electrons.

Step 5: Substitute the value of n (5 in this case) into the formula:

μ = √(5(5+2)) = √35

Therefore, the magnetic moment of the Mn²⁺ ion is √35.

The correct answer is √35.