\(n_{CuO}=\dfrac{8}{80}=0,1\left(mol\right);n_{HCl}=0,3\left(mol\right)\)
a) \(CuO+2HCl\rightarrow CuCl_2+H_2O\)
Lập tỉ lệ : \(\dfrac{0,1}{1}< \dfrac{0,3}{2}\)=> HCl dư sau phản ứng
\(n_{CuCl_2}=n_{CuO}=0,1\left(mol\right)\)
=> \(m_{CuCl_2}=135.0,1=13,5\left(g\right)\)
b)Dung dịch sau phản ứng : \(n_{HCl\left(dư\right)}=0,3-0,1.2=0,1\left(mol\right);n_{CuCl_2}=0,1\left(mol\right)\)
\(CM_{HCl}=\dfrac{0,1}{0,3}=0,33M;CM_{CuCl_2}=\dfrac{0,1}{0,3}=0,33M\)