mhh giảm=16/100.25=4(g)
mhh giảm =mH2O
pt:
CuO+H2--->Cu+H2O
x______________x
Fe2O3+3H2--->2Fe+3H2O
y__________________3y
Hệ pt:
\(\left\{{}\begin{matrix}80x+160y=16\\18x+54y=4\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=\dfrac{7}{45}\\y=\dfrac{1}{45}\end{matrix}\right.\)
=>mCuO
=>%mCuO
=>%mFe2O3