题干
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
① C2H2(g) +
O2(g) ="=" 2CO2(g)＋H2O(l) ΔH1＝-1301.0 kJ•mol-1② 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
答案(点此获取答案解析）
A
