Gọi : nFe3O4 = x mol ; nCuO = y mol
PTHH :
\(Fe3O4+4H2-^{t0}->3Fe+4H2O\)
x mol..................................3xmol
\(CuO+H2-^{t0}->Cu+H2O\)
ymol..............................ymol
Ta có HPT : \(\left\{{}\begin{matrix}232x+80y=31,2\\232x-80y=15,2\end{matrix}\right.=>x=0,1;y=0,1\)
=> \(\left\{{}\begin{matrix}mFe=0,1.56=5,6\left(g\right)\\mCu=0,1.64=6,4\left(g\right)\end{matrix}\right.\)