Question

Which of the following is a mixed oxide?

• A. \( \mathrm{Fe_2O_3} \)
• B. \( \mathrm{PbO_2} \)
• C. \( \mathrm{Pb_3O_4} \)
• D. \( \mathrm{BaO_2} \)

Hint:

Remember:
Mixed oxides involve the same metal in different oxidation states
Examples: \( \mathrm{Fe_3O_4}, \mathrm{Pb_3O_4} \)

Answer 1

The Correct Option is C

Concept: A mixed oxide is an oxide that can be considered as a combination of two different oxides of the same metal, usually involving different oxidation states. Typical representation: \[ \text{Mixed oxide} = \text{Lower oxide} + \text{Higher oxide} \]
Step 1: Analyze each option.
\( \mathrm{Fe_2O_3} \): Simple oxide of iron (only Fe\(^{3+}\))
\( \mathrm{PbO_2} \): Simple oxide of lead (only Pb\(^{4+}\))
\( \mathrm{BaO_2} \): Peroxide, contains \( \mathrm{O_2^{2-}} \)
Step 2: Examine \( \mathrm{Pb_3O_4} \). \[ \mathrm{Pb_3O_4 = 2PbO + PbO_2} \] Here:
Pb exists in both +2 and +4 oxidation states
It is a combination of two oxides of lead Hence, \( \mathrm{Pb_3O_4} \) is a mixed oxide. \[ \boxed{\mathrm{Pb_3O_4 \text{ is a mixed oxide}}} \]