Odpowiedź:
2Al+(3/2)O2 -> Al2O3 dH1 //*(-1)
S+(3/2)O2 -> SO3 dH2 //*(-3)
2Al+3S+6O2->Al2(SO4)3 dH3 //*1
dHx=dH1*(-1)+dH2*(-3)+dH3*1
dHx=(-1671,0)*(-1)+(-395,5)*(-3)+(-3437,4)*1=(-579,9)kJ/mol
