c/100=md/ms md=c*ms/100=40*200/100=80 g H2SO4
2 Al + 3 H2SO4 = Al2(SO4)3 + 3 H2
M(Al2(SO4)3) = 2A(Al) + 3A(S) + 12A(O) = 2*27+3*32+12*16= 342
M(H2SO4) = 2A(H) + A(S) + 4A(O) =98
98 g H2SO4...........342g Al2(SO4)3..............3*22,4L H2
80 g H2SO4...........................x............................y
x= 279,18 g Al2(SO4)3
y = 54,857 L H2(cn)