已知热化学方程式: ① C 2 H 2 (g) +5/2O 2 (g) == 2CO 2 (g)+H 2 O(l) ΔH1=-1301.0 kJ·mol -1 ② C(s)+ O 2 (g) == CO 2 (g) △H2=-393.5 kJ·mol -1 ③ H 2 (g)+ 1/2O 2 (g) == H 2 O(1) △H3 = -285.8 kJ·mol -1 则反应④ 2C(s)+ H 2 (g) == C 2 H 2 (g)的△H4为 |
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A.+228.2 kJ·mol -1 B.-228.2 kJ·mol -1 C.+1301.0 kJ·mol -1 D.+621.7 kJ·mol -1 |
1年前1个回答
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