Question

The number of mixed oxides from the following is: \[ {Al}_2{O}_3, {Pb}_3{O}_4, {Mn}_2{O}_7, {Fe}_3{O}_4, {V}_2{O}_5, {Sb}_2{O}_3 \] 
 

• A. 2
• B. 3
• C. 4
• D. 1

Hint:

Mixed oxides contain two different oxidation states of the same metal, such as Fe\(_3\)O\(_4\) (FeO·Fe\(_2\)O\(_3\)) and Pb\(_3\)O\(_4\) (PbO·PbO\(_2\)).

Answer 1

The Correct Option is A

Mixed oxides are compounds that contain two different oxidation states of the same element. Among the given oxides:
1. Al\(_2\)O\(_3\) → Simple oxide (not mixed)
2. Pb\(_3\)O\(_4\) (Red Lead) → Mixed oxide of Pb\(^2+\) and Pb\(^4+\)
3. Mn\(_2\)O\(_7\) → Simple oxide (not mixed)
4. Fe\(_3\)O\(_4\) (Magnetite) → Mixed oxide of Fe\(^2+\) and Fe\(^3+\)
5. V\(_2\)O\(_5\) → Simple oxide (not mixed)
6. Sb\(_2\)O\(_3\) → Simple oxide (not mixed)
Thus, the mixed oxides in the given list are Pb\(_3\)O\(_4\) and Fe\(_3\)O\(_4\), making the correct answer 2.