(1)n(CH4)=
=0.5mol,V(CH4)=0.5mol×22.4L/mol=11.2L,故答案为:0.5mol;11.2L;8g 16g/mol
(2)n(Al3+)=2n(Al2(SO4)3)=2×0.1L×1mol/L=0.2mol,n(SO42-)=0.3mol,N(SO42-)=0.3mol×NA/mol=0.3NA,故答案为:0.2;0.3NA;
(3)m(O2):m(O3)=0.6mol×32g/mol:0.4mol×48g/mol=1:1,N(O2):N(O3)=0.6NA:0.4NA=3:2,原子个数之比0.6×2NA:0.4×3NA=1:1,
它们在同温同压下的体积比是V(O2):V(O3)=0.6mol×22.4L/mol:0.4mol×22.4L/mol=3:2,
故答案为:1:1;3:2;1:1;3:2.