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Zorluk: KolayAlkanes: Properties, Reactions, and Petroleum Refining

During the fractional distillation of crude oil in a refining column, components separate based on differences in their boiling point ranges. Which of the following petroleum fractions is collected at the very top of the fractionating column?

  1. Refinery gasCevap
  2. B
    Bitumen
  3. C
    Kerosene
  4. D
    Diesel oil

Cevap

Refinery gas is collected at the very top of the fractionating column.
Refinery gas comprises short-chain alkanes containing 1 to 4 carbon atoms. Because these small molecules experience weak intermolecular forces, they possess the lowest boiling points among all petroleum fractions and rise to the coolest region at the very top of the fractionating tower.

Adım Adım Çözüm

1
Analyze how fractional distillation separates petroleum fractions.
Fractions separate according to their boiling point ranges, which depend on hydrocarbon chain length and molar mass.
Smaller alkane molecules have weaker van der Waals forces and lower boiling points.
2
Determine the temperature gradient in a fractionating column.
The bottom of the column is the hottest, while the top is the coolest.
Vapors rise through the column and condense when the temperature drops below their respective boiling points.
3
Identify the fraction with the lowest boiling point.
Refinery gas (C1C_1–C4C_4 alkanes like methane, ethane, propane, and butane) has the lowest boiling point range (<20∘C< 20^\circ\text{C}) and remains gaseous at the top.
Components with the lowest boiling points travel to the coolest section at the top before exiting.

Anahtar Kavram

Fractional Distillation of Crude Oil and Boiling Point Trends
Tahmini Süre:45s
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Alkanes: Properties, Reactions, and Petroleum Refining

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