\(a,PTHH:2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\\ \Rightarrow\text{Số nguyên tử Al là }2\\ b,n_{H_2}=\dfrac{13,44}{22,4}=0,6\left(mol\right)\\ \Rightarrow n_{Al_2\left(SO_4\right)_3}=\dfrac{1}{3}n_{H_2}=0,2\left(mol\right)\\ \Rightarrow m_{Al_2\left(SO_4\right)_3}=0,2\cdot342=68,4\left(g\right)\\ c,C_1:n_{H_2SO_4}=n_{H_2}=0,6\left(mol\right)\\ \Rightarrow m_{H_2SO_4}=0,6\cdot98=58,8\left(g\right)\\ C_2:n_{Al}=\dfrac{2}{3}n_{H_2}=0,4\left(mol\right)\\ \Rightarrow m_{Al}=0,4\cdot27=10,8\left(g\right)\\ m_{H_2}=0,6\cdot2=1,2\left(g\right)\\ \text{Bảo toàn KL: }m_{H_2SO_4}=m_{Al_2\left(SO_4\right)_3}+m_{H_2}-m_{Al}=68,4+1,2-10,8=58,8\left(g\right)\)