In cracking, what other products may be formed besides shorter-chain hydrocarbons?

• A. Alkanes.
• B. Alcohols.
• C. Alkenes.
• D. Aromatics.

Answer: (C)

Cracking breaks long-chain hydrocarbons into shorter pieces by cleaving C–C bonds under heat (and often with a catalyst). When the big molecule is split, the fragments can rearrange and lose hydrogen to form a C=C bond, producing alkenes as common byproducts. These unsaturated hydrocarbons appear alongside the shorter-chain saturated hydrocarbons and are especially valuable as feedstocks for making plastics and other chemicals. Alcohols or aromatics aren’t the typical main byproducts of simple cracking under standard conditions, whereas alkenes are a typical additional product.