`n_[Al]=[2,7]/27=0,1(mol)`
`2Al + 6HCl -> 2AlCl_3 + 3H_2 \uparrow`
`0,1` `0,3` `0,1` `0,15` `(mol)`
`a)V_[H_2]=0,15.22,4=3,36(l)`
`b)V_[dd HCl]=[0,3]/2=0,15(l)`
`=>C_[M_[AlCl_3]]=[0,1]/[0,15]~~0,67(M)`
\(n_{Al}=\dfrac{2,7}{27}=0,1\left(mol\right)\\ pthh:2Al+6HCl\rightarrow2AlCl_3+3H_2\)
0,1 0,3 0,1 0,15
\(V_{H_2}=0,15.22,4=3,36\left(l\right)\\ V_{HCl}=\dfrac{0,3}{2}=0,15\left(l\right)\\ C_{M\left(AlCl_3\right)}=\dfrac{0,1}{0,15}=\dfrac{2}{3}M\)