\(a/n_{Al}=\dfrac{8,1}{27}=0,3mol\\ n_{H_2SO_4}=\dfrac{150.19,6\%}{100\%.98}=0,3mol\\ 2Al+3H_2SO_4\xrightarrow[]{}Al_2\left(SO_4\right)_3+3H_2\\ \Rightarrow\dfrac{0,3}{2}>\dfrac{0,3}{3}\Rightarrow Al.dư\\ 2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)
0,2 0,3 0,1 0,3
\(m_{Al.dư}=8,1-0,2.27=2,7g\\ b/V_{H_2}=0,3.24,79=7,437l\)