已知下列反应的热化学方程式为:
⑴C(s)+O2(g)=CO2(g) ΔH 1=-393.5kJ/mol
⑵CH3COOH(l)+2O2(g)=2CO2(g)+2H2O(l) ΔH 2=-870.3kJ/mol
⑶H2(g)+O2(g)=H2O(l) ΔH 3=-285.8kJ/mol
2C(s)+2H2(g)+O2(g)=CH3COOH(l)的反应热(焓变)为
A.488.3 kJ/mol | B.-488.3 kJ/mol | C.-244.15 kJ/mol | D.244.15 kJ/mol |