已知下列热化学方程式:
(1)CH3COOH(l)+2O2(g)===2CO2(g)+2H2O(l) ΔH1=-870.3 kJ/mol
(2)C(s)+O2(g)===CO2(g) ΔH2=-393.5 kJ/mol
(3)2H2(g)+O2(g)===2H2O(l) ΔH3=-571.6 kJ/mol
则反应2C(s)+2H2(g)+O2(g)===CH3COOH(l)的焓变为
A.-488.3 kJ/mol | B.-244.15 kJ/mol | C.488.3 kJ/mol | D.244.15 kJ/mol |