Scientists investigate an oily liquid trapped beneath the seabed. They assess whether the liquid is crude oil and whether it could be used as a resource.
The table gives information about the deposit.
| Information | Value |
|---|---|
| Estimated amount that can be extracted | 36 million tonnes |
| Planned rate of extraction | 1.2 million tonnes per year |
| Time taken for the liquid to form naturally | millions of years |
Calculate how many years the deposit would last at the planned rate of extraction.
Explain why the liquid would be classified as a finite resource.
Material in the surrounding sediment contains the remains of microscopic organisms that lived in an ancient sea. The remains were buried beneath layers of mud.
Name the organisms and explain how their buried remains could have formed the oily liquid.
The scientists compare four compounds that could be present in material from the site.
| Compound | Molecular formula |
|---|---|
| W | CH4\text{CH}_4CH4 |
| X | C2H6\text{C}_2\text{H}_6C2H6 |
| Y | C3H6\text{C}_3\text{H}_6C3H6 |
| Z | C2H6O\text{C}_2\text{H}_6\text{O}C2H6O |
Explain which compounds are members of the homologous series of alkanes.
Name each alkane you identify.
91 exam-style questions on AQA GCSE Chemistry 7.1 Carbon compounds as fuels and feedstock, covering 7.1.1 Crude oil, hydrocarbons and alkanes, 7.1.2 Fractional distillation and petrochemicals, 7.1.3 Properties of hydrocarbons, and 7.1.4 Cracking and alkenes. Each one has a worked solution and a mark scheme showing where the marks go.