H2gC2H4g的精選

問題詳情：下列五個化學方程式：①C2H2(g)+H2(g)C2H4(g)；  ②CH4(g) H2(g)+C2H4(g)，③C(s)+2H2(g)CH4(g)；△H＝－xKJ·mol－1，④C(s)+H2(g)1/2C2H2(g)；△H＝－yKJ·mol－1，⑤C(s)+H2(氣)＝1/2C2H4(g)；△H＝－zKJ·mol－1當溫度下降時①式平衡向右...