碳碳雙鍵和碳碳單鍵的形成有什麼不同

(甲)碳碳雙鍵時,其鍵能(bond energy)比碳碳單鍵時大.(乙)碳碳雙鍵時,其鍵長(bond length)比碳碳單鍵時為短. (丙)碳碳雙鍵時,其鍵是不可以旋轉的,但碳碳單鍵時,其碳碳單鍵是可以旋轉的. (丁)碳碳雙鍵時,它是比較碳碳單鍵時活潑的(more reactive).你可以看一看,乙烷(ethane)對在四氯化碳(CCl4)的溴(bromine)是無反應的,除了有光出現時.但是乙烯(ethene)能把在四氯化碳(CCl4)的溴(bromine)脫色(decolourize).
希望幫到你.

2007-06-15 16:58:14 補充：
對不起,CCl4的中文名是四氯甲烷才對.

The single bond between the carbon (C-C) is a sigma bond. In this case, the carbon is formed by direct overlapping of the 2p orbital. However, the C=C, carbon double bond is formed by a sigma bond + a pi-bond. The pi-bond is a side way overlapping of the vacnt pi-bond. In fact, this pi-bond is weaker than the signa bond. So, the bond energy of the C=C bond is always smaller than 2 times fo the C-C bond energy.

碳單鍵
C - C
碳單鍵的有機化合物通常稱作烷

碳雙鍵
C = C
碳雙鍵的有機化合物通常稱作烯