This method is not typically used to prepare alkynes. Dehalogenation of vicinal dihalides can lead to the formation of alkenes, not alkynes.

Dehydration of alcohols is a common method to prepare alkenes. Alcohols can undergo elimination reactions to form alkynes.

This method is not typically used to prepare alkynes. As mentioned earlier, dehalogenation of vicinal dihalides usually leads to the formation of alkenes.