\(n_{MgO}=\dfrac{1.6}{40}=0.04\left(mol\right)\)
\(n_{HCl}=0.05\cdot2=0.1\left(mol\right)\)
\(MgO+2HCl\rightarrow MgCl_2+H_2O\)
Lập tỉ lệ :
\(\dfrac{0.04}{1}< \dfrac{0.1}{2}\Rightarrow HCldư\)
\(n_{HCl\left(dư\right)}=0.1-0.04\cdot2=0.02\left(mol\right)\)
\(m_{MgCl_2}=0.04\cdot95=3.8\left(g\right)\)
\(\rightarrow D\)