Question

Which transition metal does not form ‘MO’ type oxide? (M = transition metal)

• A. \( V \)
• B. \( Cr \)
• C. \( Mn \)
• D. \( Sc \)

Hint:

Transition metals exhibit multiple oxidation states, but their preferred oxidation state determines the type of oxides they form. Elements like scandium, which predominantly exist in the \( +3 \) state, do not form \( MO \) type oxides.

Answer 1

The Correct Option is D

The question asks which transition metal does not form an \( \text{MO} \) type oxide, where \( \text{M} \) is the transition metal. The candidates provided are \( V \), \( Cr \), \( Mn \), and \( Sc \). Each of these symbols represents a transition metal from the periodic table. Transition metals are known for forming various types of oxides, often affected by their oxidation states. The direct approach here is to determine the oxidation states and typical oxides formed by these metals:

1. Oxide Types:

• \( V \) (Vanadium): Typically forms oxides such as \( \text{VO} \), \( \text{V}_2\text{O}_3 \), \( \text{VO}_2 \), and \( \text{V}_2\text{O}_5 \), indicating it does form an \( \text{MO} \) type oxide.
• \( Cr \) (Chromium): Known to form \( \text{CrO} \), \( \text{Cr}_2\text{O}_3 \), and \( \text{CrO}_2, \) hence it does form an \( \text{MO} \) type oxide.
• \( Mn \) (Manganese): Can form oxides such as \( \text{MnO} \), \( \text{Mn}_2\text{O}_3 \), \( \text{MnO}_2 \), and \( \text{Mn}_2\text{O}_7, \) showing it forms an \( \text{MO} \) type oxide.
• \( Sc \) (Scandium): Forms \( \text{Sc}_2\text{O}_3 \) as its stable oxide and does not form a simple \( \text{MO} \) oxide.

2. Conclusion:

Among the given transition metals, Scandium (\( \text{Sc} \)) does not form an \( \text{MO} \) type oxide due to its limited oxidation state and specific oxide formation, which is \( \text{Sc}_2\text{O}_3 \). Therefore, the correct answer is \( \text{Sc} \).

Answer 2

Step 1: Understanding the nature of transition metal oxides Transition metals commonly form oxides in different oxidation states. The general formula \( MO \) is observed for several transition metals where the oxidation state of metal is \( +2 \).
Step 2: Examining each option
- Vanadium (V): Forms vanadium(II) oxide \( VO \).
- Chromium (Cr): Forms chromium(II) oxide \( CrO \).
- Manganese (Mn): Forms manganese(II) oxide \( MnO \).
- Scandium (Sc): Does not form \( ScO \) because scandium primarily exists in the \( +3 \) oxidation state, leading to the formation of \( Sc_2O_3 \) rather than \( ScO \).
Step 3: Conclusion Since scandium does not form \( MO \)-type oxides but instead forms \( Sc_2O_3 \), the correct answer is \( Sc \).