已知热化学方程式:
① C2H2(g) +O2(g) ="=" 2CO2(g)+H2O(l) ΔH1=-1301.0 kJ•mol-1
② C(s)+ O2(g) ="=" CO2(g) △H2=-393.5 kJ•mol-1
③ H2(g)+ O2(g) ="=" H2O(1) △H3 =" -285.8" kJ·mol-1
则反应④ 2C(s)+ H2(g) ="=" C2H2(g)的△H为
A.+228.2 kJ·mol-1 | B.-228.2 kJ·mol-1 |
C.+1301.0 kJ·mol-1 | D.+621.7 kJ·mol-1 |