6.
\(\%O=\dfrac{16n}{102}\cdot100\%=47.06\%\)
\(\Rightarrow n=3\)
\(M_X=2R+16\cdot3=102\left(đvc\right)\)
\(\Rightarrow R=27\)
\(R:Nhôm\)
\(Al_2O_3\)
7.
\(CT:Cu_xO_y\)
\(M_{oxit}=\dfrac{160}{2}=80\left(\dfrac{g}{mol}\right)\)
\(\Rightarrow64x+16y=80\)
\(\Rightarrow x=y=1\)
\(CT:CuO\)
8.
\(CT:R_2O_3\)
\(M_X=32\cdot5=160\left(\dfrac{g}{mol}\right)\)
\(\Rightarrow2R+16\cdot3=160\)
\(\Rightarrow R=56\)
\(CT:Fe_2O_3\)