Em tham khảo nha :
\(\begin{array}{l}
1)\\
a)\\
{n_K} = \dfrac{{3,9}}{{39}} = 0,1mol\\
{n_{Fe}} = \dfrac{{11,2}}{{56}} = 0,2mol\\
{n_{C{O_2}}} = \dfrac{{55}}{{44}} = 1,25mol\\
{n_{F{e_3}{O_4}}} = \dfrac{{58}}{{232}} = 0,25mol\\
b)\\
{n_{C{O_2}}} = \dfrac{{6,72}}{{22,4}} = 0,3mol\\
{n_{S{O_2}}} = \dfrac{{10,08}}{{22,4}} = 0,45mol\\
{n_{{H_2}}} = \dfrac{{3,36}}{{22,4}} = 0,15mol\\
2)\\
a)\\
{n_{N{a_2}S{O_4}}} = \dfrac{{19,88}}{{142}} = 0,14mol\\
{C_{{M_{N{a_2}S{O_4}}}}} = \dfrac{{0,14}}{{0,5}} = 0,28M\\
b)\\
{n_{CuS{O_4}}} = \dfrac{{16}}{{160}} = 0,1mol\\
{C_{{M_{CuS{O_4}}}}} = \dfrac{{0,1}}{{0,2}} = 0,5M\\
3)\\
a)\\
C{\% _{N{a_2}S{O_4}}} = \dfrac{{19,88}}{{500}} \times 100\% = 3,976\% \\
b)\\
C{\% _{CuS{O_4}}} = \dfrac{{16}}{{200}} \times 100\% = 8\%
\end{array}\)
