Câu 21:
CTHH: FexOy
Có: \(\dfrac{m_{Fe}}{m_O}=\dfrac{7}{3}\Rightarrow\dfrac{56x}{16y}=\dfrac{7}{3}\Rightarrow\dfrac{x}{y}=\dfrac{2}{3}\)
=> CTHH: Fe2O3
Câu 22:
a)
\(M_Y=0,5.32=16\left(g/mol\right)\)
\(M_X=16.2,125=34\left(g/mol\right)\)
b)
- Xét X:
Có: \(n_H:n_S=\dfrac{5,88\%}{1}:\dfrac{94,12\%}{32}=2:1\)
=> CTHH: (H2S)n
Mà MX = 34 (g/mol)
=> n = 1 => CTHH: H2S
- Xét Y:
Có: \(n_C:n_H=\dfrac{75\%}{12}:\dfrac{25\%}{1}=1:4\)
=> CTHH: (CH4)m
Mà MY = 16 (g/mol)
=> m = 1 => CTHH: CH4