`#3107.101107`
Gọi CT chung: \(\text{P}_x \text{O}_y\)
Theo quy tắc hóa trị: \(\text{V}.x = \text{II}.y \Rightarrow \dfrac{x}{y} = \dfrac{\text{II}}{\text{V}} \Rightarrow x = 2; y = 5\)
\(\Rightarrow \text{CTHH: P}_2\text{O}_5\)
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Gọi CT chung: \(\text{Fe}_x\text{O}_y\)
Theo quy tắc hóa trị: \(\text{III}.x = \text{II}.y \Rightarrow \dfrac{x}{y} = \dfrac{\text{II}}{\text{III}} \Rightarrow x = 2; y = 3\)
\(\Rightarrow \text{CTHH: Fe}_2\text{O}_3.\)