Which fraction lies directly below Refinery gases in the bottom-to-top order?

Which fraction lies directly below Refinery gases in the bottom-to-top order?

• A. Petrol
• B. Petroleum gases
• C. Kerosine
• D. Diesel

Answer: (B)

In fractional distillation, you separate hydrocarbons by boiling point, so the lightest fractions rise to the top of the column and the heaviest stay at the bottom. If you read the fractions from bottom to top, each step up represents a lighter group. Refinery gases are among the lightest; the next group directly beneath them in that bottom-to-top ordering is petroleum gases, which are slightly heavier but still gases. Petrol, kerosine, and diesel are progressively heavier and lie further down the column, not directly below refinery gases. That’s why petroleum gases is the best answer.

In fractional distillation, you separate hydrocarbons by boiling point, so the lightest fractions rise to the top of the column and the heaviest stay at the bottom. If you read the fractions from bottom to top, each step up represents a lighter group. Refinery gases are among the lightest; the next group directly beneath them in that bottom-to-top ordering is petroleum gases, which are slightly heavier but still gases. Petrol, kerosine, and diesel are progressively heavier and lie further down the column, not directly below refinery gases. That’s why petroleum gases is the best answer.