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Science · Drill 111

Science practice 111

6 questions ~9 min recommended
⏱ 00:00
Score
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Petroleum gas Gasoline Kerosene Crude oil Gas oil Lubricating oil stocks Boiler Residue Fractionating tower

Molecule Propanoic acid n-Butanol Butanone Pentane Molecular Formula CH,02 CHIO C,HO CsH12 Molecular Weight (g/mol) 74 74 72 72 Boiling Point (°C) 140 117 80 361

Petroleum, or crude oil, is refined by separating it into different by-products. This process is called fractional distillation, whereby the crude oil is heated and each different product is distilled, or drawn off, at different stages. Each product is distilled at certain temperature ranges and collected in separate receivers. Petroleum refining is carried out in a boiler and a fractionating tower. The crude oil is super-heated in the boiler to about 600°C, which vaporizes the crude oil. The vapors then rise in the tower to certain levels where they cool and condense, according to their chemical structure. When the vapor reaches a height in the tower where the temperature in the column is equal to the boiling point of the substance, the vapor turns into liquid (condenses), collects in troughs, and flows into various tanks for storage, as shown in Figure 1. Table 1 summarizes the characteristics of the by-products obtained from the fractional distillation of petroleum.

Figure 1

1. According to the passage, the temperature at which gasoline condenses is most likely:

2. According to the passage, which by-product formed in the fractionating tower condenses first?

3. According to Figure 1, fractional distillation uses which of the following as a raw material?

4. Given that naptha, another by-product of petroleum distillation, has a condensation point of approximately 90°C, between which two petroleum by-products would this substance be found in a fractionating tower?

5. According to the passage, at what temperature is most of the crude oil vaporized?

6. According to the passage, as the vapor rises in the fractionating tower:

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