Đáp án:
\(\begin{array}{l}
a)\\
{V_{{H_2}}} = 1,2395l\\
b)\\
{m_{{\rm{dd}}HCl}} = 50g\\
c)\\
{C_\% }FeC{l_2} = 12,05\%
\end{array}\)
Giải thích các bước giải:
\(\begin{array}{l}
a)\\
Fe + 2HCl \to FeC{l_2} + {H_2}\\
{n_{Fe}} = \dfrac{{2,8}}{{56}} = 0,05\,mol\\
{n_{{H_2}}} = {n_{Fe}} = 0,05\,mol\\
{V_{{H_2}}} = 0,05 \times 24,79 = 1,2395l\\
b)\\
{n_{HCl}} = 2{n_{{H_2}}} = 0,1\,mol\\
{m_{{\rm{dd}}HCl}} = \dfrac{{0,1 \times 36,5}}{{7,3\% }} = 50g\\
c)\\
{m_{{\rm{dd}}spu}} = 2,8 + 50 - 0,05 \times 2 = 52,7g\\
{n_{FeC{l_2}}} = {n_{Fe}} = 0,05\,mol\\
{C_\% }FeC{l_2} = \dfrac{{0,05 \times 127}}{{52,7}} \times 100\% = 12,05\%
\end{array}\)