Crude oil, hydrocarbons & alkanes

Crude oil is a source of hydrocarbons.

Which chemical is a hydrocarbon?

Tick (✓) one box.

Complete the sentences about crude oil.

Use words from the list.

cracking filtration fractional distillation neutralisation reduction

The hydrocarbons in crude oil are separated by........

Some of these hydrocarbons are made more useful by........

The table shows the description of three resources A, B and C.

Which resource is crude oil?

Explain your choice using information from the table.

Crude oil is resource........

Reason........

Scientists think that increased levels of carbon dioxide are causing global warming.

Which statements about the potential effects of global warming are true and which are false ?

Tick (✓) one box in each row.

These are the first four members of the alkane homologous series.

Methane CH₄ Ethane CH₃CH₃ Propane CH₃CH₂CH₃ Butane CH₃CH₂CH₂CH₃

Which statement describes the alkanes in the homologous series?

A The formula of successive alkanes differs by CH₃.

B They have different chemical properties.

C They have the same boiling points.

D They have the same general formula.

Crude oil is a source of useful chemicals called hydrocarbons.

Complete the sentence about crude oil.

Crude oil is a compound / feedstock / renewable resource used by the petrochemical industry.

The diagram shows the fractionating column used in the fractional distillation of crude oil.

Which state symbol describes the crude oil as it enters the fractionating column?

Tick (✓) one box.

Write an X on the fractionating column where it is coolest.

The table shows the boiling point of four hydrocarbons.

Which of the hydrocarbons P, Q, R or S is produced nearest to the top of the fractionating column?

Which of the hydrocarbons P, Q, R or S has the largest molecules?

Large hydrocarbons can be made more useful by cracking.

The equation shows the cracking of hydrocarbon X.

What is the formula of hydrocarbon X ?

Which homologous series of hydrocarbons does C₆H₁₄ belong to?

The hydrocarbon C₂H₄ belongs to a different homologous series.

Suggest the general formula of the homologous series that contains C₂H₄.

Tick one (✓) box.

Crude oil is a mixture of useful hydrocarbons which are separated into fractions.

Which statement describes why crude oil is called a feedstock for the petrochemical industry?

Tick one (✓) box.

Table 13.1 shows some information about the fractions in crude oil.

Table 13.1

Calculate the percentage of fraction W found in crude oil.

Write your answer in Table 13.1.

The boiling point of a fraction depends on the number of carbon atoms in the molecules.

Complete Table 13.2 by writing in the letters of three fractions shown in Table 13.1.

Table 13.2

Write the letter of the fraction shown in Table 13.1 which has the strongest intermolecular forces.

Many of the hydrocarbons in crude oil are alkanes.

Write the general formula for an alkane.

Write the formula for an alkane with 14 carbon atoms.

Fig. 12.1 shows the separation of the chemicals found in crude oil.

Fig. 12.1

Gases

What is the name of the process shown in Fig. 12.1 ?

Crude oil is heated and vaporised as it enters the column.

Describe what happens to the vapours as they rise up the column.

Which of the chemicals separated from crude oil has the smallest molecules?

Tick (✓) one box.

Fig. 12.2 shows the structure of a molecule found in crude oil.

Fig. 12.2

Which words describe the molecule?

Tick (✓) two boxes.

There are other molecules similar to Fig. 12.2 but with different numbers of carbon atoms.

Fig. 12.3 shows how the boiling point of these molecules changes with the number of carbon atoms in the molecule.

Fig. 12.3

Number of carbon atoms in the molecule

Use the graph to estimate the boiling point of the molecule shown in Fig. 12.2.

160 litres of crude oil contains 75 litres of petrol.

Calculate the percentage of petrol in the crude oil.

Give your answer to 2 significant figures.

Supplies of crude oil are running out.

Which word describes crude oil?

A Finite

B Renewable

C Reusable

D Sustainable

Alkanes are hydrocarbons with the formula C_nH_2n+2.

Which compound is an alkane?

A C₆H₈

B C₇H₁₂

C C₈H₁₆

D C₉H₂₀

Which compound is an alkane?

A C₆H₈

B C₇H₁₂

C C₈H₁₆

D C₉H₂₀

The processing of crude oil by the petrochemical industry can be shown by different experiments.

The diagram shows how crude oil can be separated into its fractions.

The crude oil is heated. Different fractions are collected at different temperatures.

What is the name of this separation technique?

Explain how a fraction is separated and collected in the experiment.

A fraction with a boiling point of about 10 °C is not collected in the experiment.

How could the experiment be improved so this fraction is collected?

The table shows the temperatures at which four different fractions are collected.

Which statements about the fractions are true, and which are false ?

Tick (✓) one box in each row.

Crude oil is a mixture of different chemicals called fractions.

What is the name of the process used to separate crude oil into fractions?

Table 13.1 shows the stages in the separation of crude oil into fractions.

The stages are not in the correct order.

Write W, X, Y and Z in the boxes to show the correct order of the stages.

Table 13.2 shows information about the different gases in the LPG (liquefied petroleum gas) fraction separated from crude oil.

Write the name of the homologous series of the gases in the LPG fraction.

Use the data in Table 13.2 to estimate the boiling point of butane.

The equation shows the reaction for methane burning in a limited amount of oxygen.

Write down the name of the hazardous gas formed in this reaction.

State why the gas identified in (d)(i) is hazardous to humans.

The alkanes are members of a homologous series.

Which statement does not explain why alkanes are a homologous series?

A They are hydrocarbons.

B They have the same general formula.

C They react in similar ways.

D They show trends in physical properties.

Look at the flowchart. It shows how crude oil is changed into useful substances.

Complete the flowchart with the name of Process 2.

Table 11.1 shows the supply and demand of two fractions of crude oil.

Explain the importance of Process 2.

Use information from Table 11.1 in your answer.

The hydrocarbon fractions from Process 1 contain different alkanes.

Table 11.2 shows the boiling point of different alkanes produced in Process 1.

Complete Table 11.2 with an estimate of the missing boiling point for an alkane molecule

with 3 carbon atoms.

Write the formula for an alkane with 7 carbon atoms.

One homologous series of organic compounds is called the alkanes.

They have the general formula C_nH_2n+2.

The alkane with one carbon atom, n = 1, is called methane.

Write down the formula of methane.

Table 13.1 shows the energy released when some alkanes burn in oxygen.

Plot a graph of number of carbon atoms against energy released using the data in Table 13.1 and draw a line of best fit.

Use the graph to predict the energy released when methane burns (1 carbon atom).

Energy released =........ kJ / mol

Hexane is a liquid alkane that burns in oxygen.

Which element in hexane is oxidised to produce water?

Give a reason for your answer.

A student burns 10.0 g of hexane.

These are his results.

Mass of hexane before burning = 10.0 g Mass of hexane after burning = 0.0 g

The law of conservation of mass is true for this reaction.

Explain why.

The table shows some hydrocarbons from crude oil.

Nonane is another hydrocarbon from crude oil.

It contains 9 carbon atoms.

Predict the formula of nonane.

Write down the name of this homologous series of hydrocarbons.

The table shows some hydrocarbons from crude oil.

Nonane is another hydrocarbon from crude oil.

It contains 9 carbon atoms.

Predict the formula of nonane.

Write down the name of this homologous series of hydrocarbons.