已知下列物质ΔfHmɵ/kJ·mol-1:C2H6(g,-84.7)、C2H4(g,52.3)、HF(g,-271.0),则反应:C2H6(g)+F2(g)=C2H4(g)+2HF(g)的ΔrHmɵ为()
A. 405kJ·mol-1
B. 134kJ·mol-1
C. -134kJ·mol-1
D. -405kJ·mol-1
反应Na2O(s)+I2(g)=2NaI(s)+1/2O2(g)的ΔrHmɵ为( )
A. 2ΔfHmɵ(NaI,s)-ΔfHmɵ(Na2O,s)
B. ΔfHmɵ(NaI,s)-ΔfHmɵ(Na2O,s)-ΔfHmɵ(I2,g)
C. 2ΔfHmɵ(NaI,s)-ΔfHmɵ(Na2O,s)-ΔfHmɵ(I2,g)
D. ΔfHmɵ(NaI,s)-ΔfHmɵ(Na2O,s)