2) Alkanes Flashcards Preview

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Flashcards in 2) Alkanes Deck (19)
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1
Q

What are alkanes?

A

Saturated hydrocarbons containing single C-C and C-H bonds.

2
Q

What are Sigma (σ) bonds?

A

Overlap of orbitals directly between the bonding atoms.

3
Q

What is the shape and bond angle around each carbon atom?

A
  • Tetrahedral.

- 109.5º.

4
Q

What is the effect of chain length on boiling point?

A
  • Increased chain length.
  • Greater surface area of contact.
  • Stronger London forces.
  • Boiling point increases.
5
Q

What is the effect of branching on boiling point?

A
  • More branching.
  • Less surface area of contact.
  • Weaker London forces.
  • Boiling point decreases.
6
Q

Why do alkanes not react with common reagents?

A
  • 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.
7
Q

In a plentiful supply of oxygen, what do alkanes completely burn to produce?

A

Carbon dioxide and water.

8
Q

In incomplete combustion, what do alkanes produce?

A

Carbon monoxide ( or solid carbon ) and water.

9
Q

Use this card to test the knowledge of the complete combustion of propane from the ‘Alkanes’ card.

A

Rate knowledge 1-5.

10
Q

Use this card to test the knowledge of the incomplete combustion of heptane from the ‘Alkanes’ card.

A

Rate knowledge 1-5.

11
Q

Why is carbon monoxide so dangerous?

A
  • Prevents oxygen from being transported around the body.

- Is odourless and colourless therefore the victim would be unaware of the poisoning.

12
Q

Use ‘Alkanes’ card to test knowledge of the bromination of methane (radical substitution).

A

Rate knowledge 1-5.

13
Q

What are the 2 limitations of radical substitution?

A
  • Further substitution.

- Reactions at different positions in a carbon chain.

14
Q

Name the process used to obtain kerosene from crude oil and explain why the process works.

A
  • Fractional distillation.

- Because fractions have different boiling points.

15
Q

Explain why the straight chain isomer of C10H22 has a higher boiling point than any of its branched chain structural isomers.

A
  • Decane has more surface contact.

- Decane has more London forces.

16
Q

Why does incomplete combustion sometimes take place?

A

Limited oxygen supply.

17
Q

What is meant by the term radical?

A

A species with an unpaired electron.

18
Q

State the conditions necessary to bring about the formation of the chlorine free radicals from Cl2.

A

UV light/high temperature.

19
Q

State the type of bond fission involved in the formation of the chlorine radicals.

A

Homolytic fission.