\(n_{Al}=\dfrac{10,8}{27}=0,4\left(mol\right)\\ PTHH:4Al+3O_2\rightarrow\left(t^o\right)2Al_2O_3\\ a,n_{O_2}=\dfrac{3}{4}.n_{Al}=\dfrac{3}{4}.0,4=0,3\left(mol\right)\\ \Rightarrow V_{O_2\left(đktc\right)}=0,3.22,4=6,72\left(l\right)\\ b,n_{Al_2O_3}=\dfrac{2.n_{Al}}{4}=\dfrac{2.0,4}{4}=0,2\left(mol\right)\\ \Rightarrow m_{Al_2O_3}=102.0,2=20,4\left(g\right)\\ c,2KClO_3\rightarrow\left(t^o\right)2KCl+3O_2\\ n_{KCl}=\dfrac{2}{3}.n_{O_2}=\dfrac{2}{3}.0,3=0,2\left(mol\right)\\ \Rightarrow m_{KClO_3}=122,5.0,2=24,5\left(g\right)\)