A crude oil fraction refers to a group of hydrocarbons with what characteristic?

A crude oil fraction refers to a group of hydrocarbons with what characteristic?

• A. Similar boiling points
• B. Different boiling points
• C. Different densities
• D. Different reactivities

Answer: (A)

The main idea is that a crude oil fraction is defined by having hydrocarbons that boil within a similar temperature range. In fractional distillation, the oil is heated and vapors rise through a column; compounds with lower boiling points rise higher before condensing, while those with higher boiling points condense lower down. A fraction is collected within a narrow temperature window, so it contains hydrocarbons whose boiling points are alike. Density or reactivity can vary among the molecules in the fraction, but the defining feature is the similar boiling points.

The main idea is that a crude oil fraction is defined by having hydrocarbons that boil within a similar temperature range. In fractional distillation, the oil is heated and vapors rise through a column; compounds with lower boiling points rise higher before condensing, while those with higher boiling points condense lower down. A fraction is collected within a narrow temperature window, so it contains hydrocarbons whose boiling points are alike. Density or reactivity can vary among the molecules in the fraction, but the defining feature is the similar boiling points.