`n_(Al) = 8.1 / 27 = 0.3 ( mol ) `
`n_(H_2SO_4) = 29.4 / 98 = 0.3 ( mol ) `
`PTHH : : 2Al + 3H_2SO_4 -> Al_2(SO_4)_3 + 3 H_2 ↑`
Ta có : `0.3 / 2 > 0.3 / 3`
`=> Al` dư ; `H_2SO_4` hết `=>` Tính theo `H_2SO_4`
`m_(Al..dư) = 27 × ( 0.3 - 0.2 ) = 2.7 ( g ) `
`m_(Al_2(SO_4)_3) = 0.1 × 342 = 34.2 ( g ) `