Đáp án:
Giải thích các bước giải:
Câu 5:
a) \[Fe + {H_2}S{O_4} \to FeS{O_4} + {H_2}\]
b) \[\begin{gathered}
{n_{{H_2}}} = \dfrac{{2,8}}{{22,4}} = 0,125{\text{mol}} \hfill \\
{\text{Theo PTHH: }}{{\text{n}}_{Fe}} = {n_{{H_2}}} = 0,125mol \hfill \\
\Rightarrow {m_{Fe}} = 0,125.56 = 7\left( g \right) \hfill \\
\Rightarrow \% {m_{Fe}} = \frac{7}{{10}}.100\% = 70\% \Rightarrow \% {m_{Cu}} = 30\% \hfill \\
\end{gathered} \]
c) Theo PTHH:
\[{n_{{H_2}S{O_4}}} = {n_{{H_2}}} = 0,125mol \Rightarrow C{\% _{{H_2}S{O_4}}} = \dfrac{{0,125.98}}{{200}}.100\% = 6,125\% \]