1)2C2H6+7O2=4CO2+6H2O 1/2=x/7 x=3,5 моль V(O2)=3,5*22,4=78,4л 2)CH4+2O2=CO2+2H2O 2/1=x/2 x=4 V(O2)=4*22,4=89,6л