Question
The hydrocarbons in crude oil are separated into fractions using fractional distillation. Complete the sentences. Choose answers from the box [2 marks] condense evaporate freeze melt In fractional distillation the crude oil is heated so the hydrocarbons __ The fractions collect as the hydrocarbons cool and __ Question 1 continues on the next page
Answer
4.3
(298 Votes)
Xylia
Elite · Tutor for 8 years
Answer
1. evaporate 2. condense
Explanation
Crude oil is a mixture of different hydrocarbon compounds. Fractional distillation is a method used to separate these hydrocarbons based on their different boiling points. The first step involves heating the hydrocarbons. This process causes the different hydrocarbons in the crude oil mixture to evaporate as each reaches its own specific boiling point. Once evaporated, the separate hydrocarbons move into the fractionating column where they become cooler and begin to condense back into a liquid state. The resulting liquid hydrocarbons, known as fractions, can then be collected separately because each one condenses at a different level within the column depending on its boiling point.