Question

làm bài 30 thôi ạ

Answer 1

b) 

Đặt : CT : B_xO_y

\(\dfrac{\%B}{\%O}=\dfrac{Bx}{16y}=\dfrac{7}{3}\)

\(\Leftrightarrow Bx=\dfrac{112}{3}y\)

\(BL:x=2,y=3\)

\(\Rightarrow B=56\)

\(CT:Fe_2O_3\)

Answer 2

30) a ) 

Đặt : CT: M_xO_y

\(TC:\)

\(\dfrac{xM}{16y}=\dfrac{9}{8}\)

\(\Leftrightarrow xM=18y\)

\(BL:x=2,y=3\)

\(\Rightarrow M=27\)

\(CT:Al_2O_3\)