Which is composed of alkenes?
welding torch fuel
polystyrene cups
gasoline
synthesized dyes

Alkenes are a class of organic substances with a double carbon-carbon bond. These organic substances are prepared from alkanes by a process named as thermal cracking. Alkenes are common raw materials for the production of a number of plastics like polypropylene, polystyrene, polyethylene and PVC. Thus, the answer for this are polystyrene cups.

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