C3H6O3
解析:已知m(H)=1.08g×2÷18=0.12g,m(C)=2.64g×12÷44=0.72g,
则m(O)=1.8g0.12g0.72g=0.96g
则n(C)∶n(H)∶n(O)=0.72÷12∶0.12÷1∶0.96÷16=1∶2∶1,则其实验式为CH2O;
故可设其分子式为 (CH2O)n,则有30n=90,解之得:n=3,故分子式为C3H6O3