Some of the compounds belong to the homologous series called the alkenes. Which hydrocarbons are alkenes? Select three compounds from P, Q, R, S, and T.

Which homologous series do the compounds which are not alkenes belong to? Select one option:

• Alcohols
• Alkanes
• Carboxylic acids
• Esters

Compound P, ${CH}_4$, burns completely in oxygen. State the names of the two products of this reaction.

Complete the sentences about fractional distillation. Use words from the list below: [colder, condense, cracked, evaporate, fractions, heated, hotter, polymers]

• Crude oil is ______________ as it enters a fractionating column.
• The fractionating column is ______________ at the top than at the bottom.
• As the vapours rise up the column, they ______________ to liquids at different heights.
• The separated mixtures of hydrocarbons are called ______________.

Crude oil is a finite resource. Explain what is meant by a finite resource.