2)
Các phản ứng xảy ra:
\(Fe + 2HCl\xrightarrow{{}}FeC{l_2} + {H_2}\)
\(2{H_2} + {O_2}\xrightarrow{{{t^o}}}2{H_2}O\)
\(2{H_2}O\xrightarrow{{đpdd}}2{H_2} + {O_2}\)
\(2Cu + {O_2}\xrightarrow{{{t^o}}}2CuO\)
\(CuO + {H_2}\xrightarrow{{{t^o}}}Cu + {H_2}O\)
3)
\({m_{dd}} = {m_{NaCl}} + {m_{{H_2}O}} = 50 + 150 = 200{\text{ gam}}\)
\( \to C{\% _{NaCl}} = \frac{{50}}{{200}} = 25\% \)
