$Đáp$ $án$ $+$ $Giải$ $thích$ $các$ $bước$ $giải$ $:$
$Câu$ $2$ $:$
$PTHH$ $:$
$Al_2 O_3$ $+$ $3H_2 SO_4$ $→$ $Al_2 (SO_4)_3$ $+$ $3H_2 O$
$n_ {Al_2 O_3}$ $=$ $\frac{2,04}{102}$ $=$ $0,02$ $(mol)$
$Theo$ $pt$ $:$ $n_{H_2 SO_4}$ $=$ $3×n_ {Al_2 O_3}$ $=$ $0,06$ $(mol)$
$⇒$ $m_{H_2 SO_4}$ $=$ $0,06×98$ $=$ $5,88$ $(g)$
$⇒$ $C$%$_{H_2 SO_4}$ $=$ $\frac{5,88}{100}$$×100$% $=$ $5,88$%
$Chúc$ $bn$ $hk$ $tốt$ $!!$ $:))))$
$Xin$ $ctlhn$ $ạ.$
