\(m_{H2SO4}=19,6\%.150=29,4\left(g\right)\Rightarrow n_{H2SO4}=\dfrac{29,4}{98}=0,3\left(mol\right)\)
Pt : \(MgO+H_2SO_4\rightarrow MgSO_4+H_2O\)
Theo Pt : \(n_{H2SO4}=n_{MgO}=0,3\left(mol\right)\)
\(\Rightarrow m_{MgO}=0,3.40=12\left(g\right)\)
Chúc bạn học tốt