2) Alkanes Flashcards
What are alkanes?
Saturated hydrocarbons containing single C-C and C-H bonds.
What are Sigma (σ) bonds?
Overlap of orbitals directly between the bonding atoms.
What is the shape and bond angle around each carbon atom?
- Tetrahedral.
- 109.5º.
What is the effect of chain length on boiling point?
- Increased chain length.
- Greater surface area of contact.
- Stronger London forces.
- Boiling point increases.
What is the effect of branching on boiling point?
- More branching.
- Less surface area of contact.
- Weaker London forces.
- Boiling point decreases.
Why do alkanes not react with common reagents?
- C-C and C-H σ bonds are strong.
- C-C bonds are non-polar.
- C-H bond can be considered to be non-polar.
In a plentiful supply of oxygen, what do alkanes completely burn to produce?
Carbon dioxide and water.
In incomplete combustion, what do alkanes produce?
Carbon monoxide ( or solid carbon ) and water.
Use this card to test the knowledge of the complete combustion of propane from the ‘Alkanes’ card.
Rate knowledge 1-5.
Use this card to test the knowledge of the incomplete combustion of heptane from the ‘Alkanes’ card.
Rate knowledge 1-5.
Why is carbon monoxide so dangerous?
- Prevents oxygen from being transported around the body.
- Is odourless and colourless therefore the victim would be unaware of the poisoning.
Use ‘Alkanes’ card to test knowledge of the bromination of methane (radical substitution).
Rate knowledge 1-5.
What are the 2 limitations of radical substitution?
- Further substitution.
- Reactions at different positions in a carbon chain.
Name the process used to obtain kerosene from crude oil and explain why the process works.
- Fractional distillation.
- Because fractions have different boiling points.
Explain why the straight chain isomer of C10H22 has a higher boiling point than any of its branched chain structural isomers.
- Decane has more surface contact.
- Decane has more London forces.
