Question

What are x and y in the following reaction?
$x \text{Pb}_3\text{O}_4 \rightarrow y \text{PbO} + \text{O}_2$

• A. $x=3,\ y=6$
• B. $x=2,\ y=4$
• C. $x=2,\ y=5$
• D. $x=2,\ y=6$

Hint:

In Pb$_3$O$_4$, treat the mixed oxidation state carefully to conserve atoms and charge.

Answer 1

The Correct Option is D

Each Pb$_3$O$_4$ contains 2 Pb$^{2+}$ and 1 Pb$^{4+}$. So for 2 molecules: We get 4 Pb$^{2+}$ and 2 Pb$^{4+}$ → Total 6 Pb atoms. Pb$^{4+}$ gets reduced to Pb$^{2+}$ and oxygen is released: $2 \text{Pb}_3\text{O}_4 \rightarrow 6 \text{PbO} + \text{O}_2$