A stop-motion animation that explains the elimination mechanism. This is part of the AQA A-level Chemistry course. This typically occurs for primary or secondary haloalkanes in the presence of a strong base.
Technically, this is called an 'E2 elimination' because the rate-determining step involves two molecules: a haloalkane and a hydroxide ion. Tertiary haloalkanes often undergo an alternative mechanism called 'E1', which does not require a strong base.
For both E1 and E2 reactions, when there is an option, the resulting double bond tends to be more substituted. This is due to the stabilisation of the carbocation intermediate (E1) or transition state (E2). This is known as Zaytsev's rule, named after the Russian chemist Alexander Zaytsev.
