Question

Which of the following 3d metal forms only dihalide

• A. Titanium
• B. Vanadium
• C. Manganese
• D. Iron
• E. Zinc

Hint:

Zinc is not a typical transition metal as it has a full d\(^{10}\) configuration and shows only a +2 oxidation state.

Answer 1

Answer: (E)

Step 1: Understanding the Concept
This question asks to identify a 3d transition metal that exhibits only one stable oxidation state (+2) in its compounds, specifically its halides. This is determined by the element's electronic configuration.
Step 2: Detailed Explanation
Let's analyze the common oxidation states of the given metals:

Titanium (Ti): Shows oxidation states of +2, +3, and +4. It forms halides like TiCl₂, TiCl₃, and TiCl₄.
Vanadium (V): Shows a wide range of oxidation states from +2 to +5. It forms halides like VCl₂, VCl₃, VCl₄.
Copper (Cu): Shows oxidation states of +1 and +2. It forms halides like CuCl and CuCl₂.
Chromium (Cr): Shows multiple oxidation states, with +2, +3, and +6 being common. It forms CrCl₂, CrCl₃, etc.
Zinc (Zn): Has the electronic configuration \([\text{Ar}] 3d^{10} 4s^2\). To form a chemical bond, it can easily lose the two electrons from its outermost 4s orbital. Once these are lost, it attains a very stable configuration with a completely filled 3d subshell (\([\text{Ar}] 3d^{10}\)). Removing an electron from the stable 3d¹⁰ shell requires a very high amount of energy. Therefore, Zinc almost exclusively exhibits the +2 oxidation state in its compounds. It forms only dihalides (e.g., ZnCl₂, ZnBr₂).
Step 3: Final Answer
Zinc is the only metal among the options that forms only dihalides, as its only stable oxidation state is +2.