AQA · GCSE · Chemistry
Course version: 8462 · Version from Sept 2018
Most of the hydrocarbons in crude oil are hydrocarbons called alkanes.
Full specification wording
Crude oil, hydrocarbons and alkanes: Most of the hydrocarbons in crude oil are hydrocarbons called alkanes.
Alkanes are a family of hydrocarbons that contain only single covalent bonds between carbon atoms.
Checked against the AQA 8462 specification (opens in a new tab) on .
- Point 4 of 4
Study notes
From the checked teaching notes for this specification point.
The idea
Alkanes are a family of hydrocarbons that contain only single covalent bonds between carbon atoms. They are described as saturated hydrocarbons because each carbon atom is bonded to the maximum number of hydrogen atoms possible. Most of the hydrocarbons found in crude oil are alkanes. The general formula for alkanes is CₙH₂ₙ₊₂, where n is the number of carbon atoms. For example, methane has one carbon atom and four hydrogen atoms (CH₄), ethane has two carbon atoms and six hydrogen atoms (C₂H₆), propane has three carbon atoms and eight hydrogen atoms (C₃H₈), and butane has four carbon atoms and ten hydrogen atoms (C₄H₁₀). Alkanes are relatively unreactive but burn well, making them useful as fuels.
What earns the marks
- Alkanes are hydrocarbons that contain only single covalent bonds between carbon atoms.
- Alkanes are described as saturated hydrocarbons.
- Most of the hydrocarbons in crude oil are alkanes.
- The general formula for alkanes is CₙH₂ₙ₊₂.
- Examples include methane (CH₄), ethane (C₂H₆), propane (C₃H₈) and butane (C₄H₁₀).
- Alkanes burn well and are used as fuels.
Common mistakes and how to put them right
Describing alkanes as unsaturated.
Put it right by stating they are saturated because they contain only single bonds.
Applying the general formula CₙH₂ₙ to alkanes.
Put it right by using CₙH₂ₙ₊₂ for alkanes.
Stating that alkanes contain double bonds.
Put it right by explaining that alkanes have only single covalent bonds.
Exam tips
- Use the term 'saturated' and explain that it means only single bonds are present.
- Apply the general formula CₙH₂ₙ₊₂ to work out the formula of an alkane from its carbon number.
- Name the first four alkanes correctly: methane, ethane, propane and butane.
Try the lesson
The start of the Crude oil, hydrocarbons and alkanes: Most of the hydrocarbons in crude oil are hydrocarbons called alkanes. lesson, made from checked teaching notes for this specification point.
Have a go first
Crude oil is a mixture of many different compounds. What name is given to the family of hydrocarbons that makes up most of crude oil?
Listen
Alkanes are a family of hydrocarbons that contain only single covalent bonds between carbon atoms. They are described as saturated hydrocarbons because each carbon atom is bonded to the maximum number of hydrogen atoms possible. Most of the hydrocarbons found in crude oil are alkanes. The general formula for alkanes is CₙH₂ₙ₊₂, where n is the number of carbon atoms. For example, methane has one carbon atom and four hydrogen atoms (CH₄), ethane has two carbon atoms and six hydrogen atoms (C₂H₆), propane has three carbon atoms and eight hydrogen atoms (C₃H₈), and butane has four carbon atoms and ten hydrogen atoms (C₄H₁₀). Alkanes are relatively unreactive but burn well, making them useful as fuels. A strong answer earns marks for these points. Alkanes are hydrocarbons that contain only single covalent bonds between carbon atoms. Alkanes are described as saturated hydrocarbons. Most of the hydrocarbons in crude oil are alkanes. The general formula for alkanes is CₙH₂ₙ₊₂. A common slip: Describing alkanes as unsaturated. Instead, stating they are saturated because they contain only single bonds. Exam tip: Use the term 'saturated' and explain that it means only single bonds are present.
See it
Label the diagram
Some boxes have lost their names. Pick the right name for each number.
1Box 1
2Box 2
3Box 3
There is more to this lesson
The full lesson goes on to check your understanding and help you earn the marks. Create a free account to carry on, with your progress saved.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge
Test your understanding of Crude oil, hydrocarbons and alkanes: Most of the hydrocarbons in crude oil are hydrocarbons called alkanes.
Active recall beats re-reading. Take an instant quiz now to test what you’ve learned and lock it into long-term memory.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge