已知:C(s)+
O 2(g)
CO(g) Δ H 1 = —110.5 kJ/mol
CO(g)+
O 2(g)
CO 2(g) Δ H 2 = —283.0 kJ/mol
则反应C(s)+O 2(g)
CO 2(g)的反应热为( )
A.172.5 kJ/mol B.—172.5 kJ/mol C.393.5 kJ/mol D.—393.5 kJ/mol
D
根据盖斯定律可知,①+②即得到C(s)+O 2(g)=CO 2(g),所以该反应的反应热为△H=—110.5 kJ/mol—283.0 kJ/mol=—393.5 kJ/mol,答案选D。