Among the listed refinery products, which one typically has the maximum °API gravity (i.e., is the lightest)?

Introduction:
°API gravity is an inverse measure of density: higher °API means lighter material. Understanding relative °API among common products helps in tank farm operations, custody transfer, and product identification.

Given Data / Assumptions:

• Products considered: petrol (gasoline), kerosene, diesel, furnace oil, and heavy residues.
• Typical refinery product properties apply.

Concept / Approach:
Gasoline is the lightest among the listed fuels, followed by kerosene, then diesel; furnace oil and residues are much heavier. Therefore, gasoline exhibits the highest °API gravity among the options provided.

Step-by-Step Solution:
Rank by density: gasoline < kerosene < diesel < furnace oil < vacuum residue.Translate to °API: gasoline has the highest °API.Select petrol (gasoline).

Verification / Alternative check:
Typical values: gasoline ~60–70 °API; kerosene ~38–48; diesel ~30–40; furnace oil/resid much lower °API.

Why Other Options Are Wrong:
Diesel/kerosene: Heavier than gasoline (lower °API).Furnace oil/vacuum residue: Heaviest, lowest °API.

Common Pitfalls:
Confusing cetane/octane properties with density/°API; they are independent metrics.

Final Answer:
Petrol (gasoline)