Hydrocarbon cracking process identification

Steps:

• Recall that cracking breaks large alkane chains into smaller alkenes and alkanes using heat and a catalyst.
• Identify standard conditions: thermal cracking uses high heat alone; catalytic cracking uses heat with acid catalysts like zeolite.
• Note nickel catalysts are for hydrogenation, not cracking.
• Distinguish fractional distillation as separation by boiling points without catalysts.

Why A is correct:

• Cracking employs heat with acid catalysts to lower activation energy and produce alkenes, per industrial catalytic cracking definitions.

Why the others are wrong:

• B: "Fractional cracking" is not standard; nickel catalyzes hydrogenation, not cracking.
• C: Nickel catalyst is incorrect for cracking, which requires acid types.
• D: Fractional distillation separates fractions by vaporization and condensation, needing no acid catalyst.

Final answer: A