mhh + m H2=mKL+mH2O ; H2-->H2O => số mol = nhau = x mol
=> bt khối lượng ; 24+2x=17,6+18x=> x=0,4 mol => m h2o=0,4.18=7,2 g
\(CuO+H_2-t^0->Cu+H_2O\)
a..............a.....................a.........a
\(Fe_xO_y+yH_2-t^0->xFe+yH_2O\)
b...............by...................bx.............by
\(\left\{{}\begin{matrix}80a+56xb+16yb=24\\64a+56bx=17,6\end{matrix}\right.\)
\(\Rightarrow a+by=0,4\left(mol\right)\)
\(m_{H_2O}=18\left(a+by\right)=18.0,4=7,2\left(g\right)\)