C(s)+O2(g)=CO2(g)△H1=﹣393.5kJ/mol
CH3COOH(l)+2O2(g)=2CO2(g)+2H2O(l)△H2=﹣870.3kJ/mol
H2(g)+ O2(g)=H2O(l)△H3=﹣285.8kJ/mol
2C(s)+2H2(g)+O2(g)=CH3COOH(l) 的反应热△H(焓变)为( )