Alkenes cations, preferred geometries

However, although the Z-alkene is more stable, the -alkene is formed faster under these conditions the route to the -alkene must have a smaller activation energy barrier than trans addition. This is quite easy to understand the intermediate cation has no double-bond geometry because the cationic C is sp hybridized (linear). When chloride attacks, it prefers to attack from the side of the H atom rather than the (bigger) methyl group. 

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