3H2SO4+2Al= Al2(SO4)3 +3H2 mч(H2SO4)= 490*0.12=58.8г M(H2SO4)= 2+96=98 M(Al2(SO4)3)= 54+288= 342 m(Al2(SO4)3)= 58.8*342/98=205.2 г Ответ: 205,2г