\(n_{Al_2O_3}=\dfrac{10,2}{102}=0,1\left(mol\right)\)
PTHH: \(Al_2O_3+6HCl\rightarrow2AlCl_3\downarrow+3H_2O\)
a. Theo PT ta có: \(n_{AlCl_3}=2.n_{Al_2O_3}=2.0,1=0,2\left(mol\right)\)
\(\Rightarrow m_{AlCl_3}=0,2.133,5=26,7\left(g\right)\)
b. Theo PT ta có: \(n_{HCl}=6.n_{Al_2O_3}=6.0,1=0,6\left(mol\right)\)
\(\Rightarrow m_{HCl}=0,6.36,5=21,9\left(g\right)\)
\(\Rightarrow C\%dd_{HCl}=\dfrac{21,9}{500}.100\%=4,38\%\)