Carbon compounds as fuels and feedstock: Practice Questions

Crude oil is a finite resource found in rocks. Which of the following best describes the composition of crude oil?

In a fractional distillation column, where are the hydrocarbons with the highest boiling points collected, and what is a characteristic property of this fraction?

A sample of octadecane (\(C_{18}H_{38}\)) is cracked. The products are one molecule of propene, two molecules of ethene, and one molecule of an alkane.
What is the molecular formula of the alkane produced?

Which of the following is the general formula for the homologous series of alkanes?

Hydrocarbons can be separated into fractions by fractional distillation. Which statement correctly explains how this process works?

State the general formula for the homologous series of alkanes and identify the name of the alkane that contains exactly three carbon atoms.

Explain why heavy fuel oil has a higher viscosity than petrol, in terms of the size of the molecules and their intermolecular forces.

A sample of decane (\(C_{10}H_{22}\)) is cracked to produce ethene and one other hydrocarbon.
Write a balanced symbol equation for this reaction and explain, in terms of supply and demand, why this process is economically necessary in the petrochemical industry.

Hydrocarbons are separated from crude oil using the process of fractional distillation.

a) Explain why the fractional distillation column is hotter at the bottom than at the top in terms of the properties of the hydrocarbons.
b) Describe the trend in boiling point and viscosity of the fractions as the molecules decrease in size.
c) Name the first four members of the alkanes homologous series and state their general formula.