a) \(CuO+2HCl-->.CuCl2+H2O\)
\(n_{CuO}=\frac{4}{80}=0,05\left(mol\right)\)
\(n_{HCl}=\frac{2,92}{36,5}=0,08\left(mol\right)\)
\(\frac{0,05}{1}>\frac{0,08}{2}\Rightarrow HCl\) hết , CuO dư
\(n_{CuO}=\frac{1}{2}n_{HCl}=0,04\left(mol\right)\)
\(n_{CuO}dư=0,05-0,04=0,01\left(mol\right)\)
\(m_{CuO}dư=0,01.80=0,8\left(g\right)\)
b) \(CuO+H2-->Cu+H2O\)
\(n_{H2}=n_{CuO}=0,05\left(mol\right)\)
\(V_{H2}=0,05.22,4=1,12\left(l\right)\)
\(n_{Cu}=n_{CuO}=0,05\left(mol\right)\)
m\(_{Cu}=0,0.64=3,2\left(g\right)\)