\(n_{Al}=\dfrac{2,7}{27}=0,1\left(mol\right)\\ PTHH:4Al+3O_2\underrightarrow{t^o}2Al_2O_3\\ Mol:0,1\rightarrow0,075\rightarrow0,05\\ \rightarrow\left\{{}\begin{matrix}V_{kk}=\dfrac{0,075.22,4}{20\%}=8,4\left(l\right)\\m_{Al_2O_3}=0,05.102=5,1\left(g\right)\end{matrix}\right.\)