\(n_{Mg}=\frac{1,2}{24}=0,05mol;n_{O_2}=\frac{3,36}{22,4}=0,15mol\)
\(2Mg\) + \(O_2\) \(\rightarrow\) \(2MgO\)
\(\frac{0,05}{2}\) < \(\frac{0,15}{1}\) Vậy \(O_2\) dư
\(0,05\) \(\rightarrow\) \(0,25\) \(\rightarrow\) \(0,05\)
\(n_{O_2dư}=0,15-0,025=0,125mol\)
\(m_{O_2dư}=0,125.32=4g\)
Sản phẩm là: \(MgO\)
\(m_{MgO}=0,05.\left(24+16\right)=0,05.40=2g\)