Em tham khảo nha:
\(\begin{array}{l}
1)\\
a)\\
{N_{Cl}} = 0,4 \times 2 \times 6 \times {10^{23}} = 4,8 \times {10^{23}}\\
b)\\
{n_{F{e_2}{O_3}}} = \dfrac{{0,8}}{2} = 0,4\,mol\\
{m_{F{e_2}{O_3}}} = 0,4 \times 160 = 64g\\
2)\\
{M_A} = 2,75 \times {M_{C{H_4}}} = 2,75 \times 16 = 44dvC\\
{M_B} = 1,4545 \times {M_A} = 1,4545 \times 44 = 64dvC
\end{array}\)