Câu 15 :
\(n_{Al}=\dfrac{10,8}{27}=0,4\left(mol\right)\)
Pt : \(2Al+6HCl\rightarrow2AlCl_3+3H_2\)
0,4----->1,2------->0,4------>0,6
\(m_{HCl}=1,2.36,5=43,8\left(g\right)\)
\(\Rightarrow m_{ddHCl}=\dfrac{43.8.100\%}{25\%}=175,2\left(g\right)\)
\(m_{ddspu}=10,8+175,2-0,6.2=184,8\left(g\right)\)
\(C\%_{AlCl3}=\dfrac{0,4.133,5}{184,8}.100\%=28,9\%\)