Em tham khảo nha:
\(\begin{array}{l}
a)\\
{d_{{O_2}/{H_2}}} = \dfrac{{32}}{2} = 16\\
b)\\
{d_{{N_2}/kk}} = \dfrac{{28}}{{29}} = 0,9655\\
c)\\
{m_X} = 0,2 \times 44 + 0,1 \times 16 = 10,4g\\
{n_X} = 0,2 + 0,1 = 0,3\,mol\\
{M_X} = \dfrac{{10,4}}{{0,3}} = 34,67\,g/mol\\
{d_{X/{H_2}}} = \dfrac{{34,67}}{2} = 17,335\\
d)\\
{m_T} = 0,3 \times 16 + 0,4 \times 26 = 15,2g\\
{n_T} = 0,3 + 0,4 = 0,7\,mol\\
{M_T} = \dfrac{{15,2}}{{0,7}} = 21,74\,g/mol\\
{d_{T/{O_2}}} = \dfrac{{21,74}}{{32}} = 0,679375
\end{array}\)
