CTHH của MgxOy
\(\dfrac{x}{y}=\dfrac{II}{II}=\dfrac{2}{2}\)
=> CTHH: MgO
b) CTHH của Fex(SO4)y
\(\dfrac{x}{y}=\dfrac{II}{III}=\dfrac{2}{3}\)
=> CTHH: Fe2(SO4)3
a. Gọi CTHH là: \(\overset{\left(II\right)}{Mg_x}\overset{\left(II\right)}{O_y}\)
Ta có: \(II.x=II.y\)
\(\Leftrightarrow\dfrac{x}{y}=\dfrac{II}{II}=\dfrac{1}{1}\Leftrightarrow\left\{{}\begin{matrix}x=1\\y=1\end{matrix}\right.\)
Vậy CTHH là: MgO
b. Gọi CTHH là: \(\overset{\left(III\right)}{Fe_a}\overset{\left(II\right)}{\left(SO_4\right)_b}\)
Ta có: \(III.a=II.b\)
\(\Leftrightarrow\dfrac{a}{b}=\dfrac{II}{III}=\dfrac{2}{3}\Leftrightarrow\left\{{}\begin{matrix}a=2\\b=3\end{matrix}\right.\)
Vậy CTHH là: Fe2(SO4)3