Question

Which of the following does not represent property stated against it ?

• A. CO⁺² < Fe⁺² < Mn⁺² - Ionic size
• B. Ti < V < Mn - Number of oxidation states
• C. Cr⁺² < Mn⁺² < Fe⁺² - Paramagnetic behaviour
• D. Sc > Cr > Fe - Density

Answer 1

The Correct Option is D

Let's evaluate each option:

• Option A: \( \text{Co}^{2+} < \text{Fe}^{2+} < \text{Mn}^{2+} \) - Ionic size: This is correct. The ionic size increases as we move from Co²⁺ to Fe²⁺ to Mn²⁺.
• Option B: \( \text{Ti} < \text{V} < \text{Mn} \) - Number of oxidation states: This is correct. Ti has fewer oxidation states than V, and V has fewer than Mn.
• Option C: \( \text{Cr}^{2+} < \text{Mn}^{2+} < \text{Fe}^{2+} \) - Paramagnetic behaviour: This is correct. The number of unpaired electrons increases from Cr²⁺ to Mn²⁺ to Fe²⁺, increasing the paramagnetic behavior.
• Option D: \( \text{Sc} > \text{Cr} > \text{Fe} \) - Density: This is incorrect. The actual trend is \( \text{Fe} > \text{Cr} > \text{Sc} \) for density.

The correct answer is (D) : Sc > Cr > Fe - Density.