Question

Answer 1

Câu 3:

\(a,BTKL:m_{Mg}+m_{O_2}=m_{MgO}\\ \Rightarrow m_{O_2}=50,4-30,2=20,2(g)\\ b,2Mg+O_2\xrightarrow{t^o}2MgO\)

Câu 4:

\(a,CTTQ:Al_x^{III}\left(SO_4\right)_y^{II}\\ \Rightarrow x.III=y.II\Rightarrow\dfrac{x}{y}=\dfrac{2}{3}\Rightarrow x=2;y=3\\ \Rightarrow Al_2\left(SO_4\right)_3\\ b,CTTQ:Fe_x^{III}\left(NO_3\right)_y^I\\ \Rightarrow x.III=y.I\Rightarrow\dfrac{x}{y}=\dfrac{1}{3}\Rightarrow x=1;y=3\\ \Rightarrow Fe\left(NO_3\right)_3\)