Hỗn hợp X gồm Cu2O, FeO và kim loại M (M có hóa trị không đổi, số mol

* Hướng dẫn giải

Chọn đáp án A

$$\begin{gathered} + \left\{\begin{array}{l}C{u}_{2}O: x mol\\ FeO: y mol\\ M: 0,5(x+y) mol\end{array}\right\}\stackrel{2,1 mol HN{O}_3}{\to }\left\{\begin{array}{l}C{u}^{2+}, F{e}^{3+}\\ M^{n+}, N{O_3}^{-},...\end{array}\right\}+NO\uparrow +H_{2}O \\ \begin{array}{l}\mathit{+}\mathit{ }\mathit{B}\mathit{T}\mathit{K}\mathit{L}\mathit{:}\mathit{ }\mathit{ }{\mathit{n}}_{{\mathit{H}}_{\mathit{2}}\mathit{O}}\mathit{=}\frac{\mathit{48}\mathit{+}\mathit{2}\mathit{,}\mathit{1}\mathit{.}\mathit{63}\mathit{-}\mathit{157}\mathit{,}\mathit{2}\mathit{-}\mathit{0}\mathit{,}\mathit{2}\mathit{.}\mathit{30}}{\mathit{18}}\mathit{=}\mathit{0}\mathit{,}\mathit{95}\mathit{ }\mathit{ }\mathit{m}\mathit{o}\mathit{l}\mathit{\Rightarrow }{\mathit{n}}_{\mathit{N}{{\mathit{H}}_{\mathit{4}}}^{\mathit{+}}}\mathit{=}\frac{\mathit{2}\mathit{,}\mathit{1}\mathit{-}\mathit{0}\mathit{,}\mathit{95}\mathit{.}\mathit{2}}{\mathit{4}}\mathit{=}\mathit{0}\mathit{,}\mathit{05}\mathit{ }\mathit{ }\mathit{m}\mathit{o}\mathit{l}\mathit{.}\\ \mathit{+}\mathit{ }\mathit{ }{\mathit{n}}_{{\mathit{H}}^{\mathit{+}}}\mathit{=}\mathit{4}{\mathit{n}}_{\mathit{N}\mathit{O}}\mathit{+}\mathit{10}{\mathit{n}}_{\mathit{N}{{\mathit{H}}_{\mathit{4}}}^{\mathit{+}}}\mathit{+}\mathit{2}{\mathit{n}}_{{\mathit{O}}^{\mathit{2}\mathit{-}}}\mathit{\Rightarrow }{\mathit{n}}_{{\mathit{O}}^{\mathit{2}\mathit{-}}}\mathit{=}\frac{\mathit{2}\mathit{,}\mathit{1}\mathit{-}\mathit{0}\mathit{,}\mathit{2}\mathit{.}\mathit{4}\mathit{-}\mathit{0}\mathit{,}\mathit{05}\mathit{.}\mathit{10}}{\mathit{2}}\mathit{=}\mathit{0}\mathit{,}\mathit{4}\mathit{ }\mathit{ }\mathit{m}\mathit{o}\mathit{l}\mathit{\Rightarrow }{\mathit{n}}_{\mathit{M}}\mathit{=}\mathit{0}\mathit{,}\mathit{2}\mathit{ }\mathit{ }\mathit{m}\mathit{o}\mathit{l}\mathit{.}\\ \mathit{+}\mathit{ }\mathit{ }\{\begin{array}{l}BTE\mathrm{:}\mathrm{ }\mathrm{ }\mathrm{2}x\mathrm{+}y\mathrm{+}\mathrm{0}\mathrm{,}\mathrm{2}n\mathrm{=}\mathrm{0}\mathrm{,}\mathrm{2}\mathrm{.}\mathrm{3}\mathrm{+}\mathrm{0}\mathrm{,}\mathrm{05}\mathrm{.}\mathrm{8}\mathrm{=}\mathrm{1}\\ m_X\mathrm{=}\mathrm{144}x\mathrm{+}\mathrm{72}y\mathrm{+}\mathrm{0}\mathrm{,}\mathrm{2}M\mathrm{=}\mathrm{48}\end{array}\mathit{\Rightarrow }\{\begin{array}{l}\mathrm{2}x\mathrm{+}y\mathrm{=}\mathrm{1}\mathrm{-}\mathrm{0}\mathrm{,}\mathrm{2}n\\ \mathrm{72}\mathrm{(}\mathrm{2}x\mathrm{+}y\mathrm{)}\mathrm{+}\mathrm{0}\mathrm{,}\mathrm{2}M\mathrm{=}\mathrm{48}\end{array}\mathit{\Rightarrow }\mathit{72}\mathit{(}\mathit{1}\mathit{-}\mathit{0}\mathit{,}\mathit{2}\mathit{n}\mathit{)}\mathit{+}\mathit{0}\mathit{,}\mathit{2}\mathit{M}\mathit{=}\mathit{48}\\ \mathit{\Rightarrow }\mathit{0}\mathit{,}\mathit{2}\mathit{M}\mathit{=}\mathit{14}\mathit{,}\mathit{4}\mathit{n}\mathit{-}\mathit{24}\mathit{\Rightarrow }\mathit{n}\mathit{=}\mathit{2}\mathit{;}\mathit{ }\mathit{ }\mathit{M}\mathit{=}\mathit{24}\mathit{ }\mathit{ }\mathit{\left(}\mathit{M}\mathit{g}\mathit{\right)}\mathit{\Rightarrow }\mathit{\%}\mathit{M}\mathit{g}\mathit{=}\mathit{10}\mathit{\%}\mathit{.}\end{array} \end{gathered}$$