Organic Chemistry

Question 1

What is the general formula for an alcohol?

Answer 1

CnH2n+1OH

Question 2

What happens to the boiling point of an alcohol as the chain length increases?

Answer 2

The boiling point increases

Question 3

Why does the boiling point of an alcohol increase as the chain length increases?

Answer 3

• There is a greater surface area

- Therefore a stronger induced dipole

Question 4

What happens to the solubility of an alcohol as the chain length increases?

Answer 4

The solubility decreases

Question 5

How can alcohols be used as fuels?

Answer 5

They can be combusted

Question 6

What is used to oxidise primary/secondary alcohols?

Answer 6

Acidified potassium dichromate

Question 7

What can primary alcohols be oxidised to?

Answer 7

• Aldehydes (distilled straight away)

- Carboxylic acids (heated under reflux)

Question 8

How can we distinguish between primary and secondary alcohols?

Answer 8

Use Fehling’s solution, only primary alcohols will react

Question 9

What can secondary alcohols be oxidised to?

Answer 9

Ketones

Question 10

How can alcohols be dehydrated?

Answer 10

• Water molecule eliminated by using concentrated sulphuric acid/phosphoric acid
• Heated and passed over aluminium oxide
• Alkene formed

Question 11

What is the general formula for an alkane?

Answer 11

CnH2n+2

Question 12

What are the two factors that affect the boiling point of an alkane?

Answer 12

• Chain length

- Branching

Question 13

How is the boiling point of an alkane affected by chain length?

Answer 13

• Longer chain = greater surface area

- Larger dipole-dipole forces

Question 14

How is the boiling point of an alkane affected by branching?

Answer 14

• More branching = lower boiling point
• Smaller surface area
• Fewer dipole-dipole forces

Question 15

What are the three steps of radical substitution?

Answer 15

• Initiation
• Propagation
• Termination

Question 16

What are the two types of bonds that alkenes can have?

Answer 16

• Pi bonds: overlap of p-orbitals above and below carbon atoms
• Sigma bonds: direct overlap of electron clouds

Question 17

What is Markownikoff’s rule?

Answer 17

Hydrogen attaches to the carbon with the most hydrogens attached to it

Question 18

What is fission?

Answer 18

The breaking of covalent bonds

Question 19

What is bond formation?

Answer 19

Bond formation is when two oppositely charged ions/radicals collide

Question 20

How can diols be formed?

Answer 20

Alkene + potassium manganate (VIII)

Question 21

What are free radicals?

Answer 21

Very reactive species with an unpaired electron

Question 22

What are halogenoalkanes?

Answer 22

• Saturated organic compounds

- Contain carbon and at least one halogen atom

Question 23

What are nucleophiles?

Answer 23

• Electron pair donors
• Will attack electron poor areas
• Usually has some type of negative charge

Question 24

Why is radical substitution limited in its use of the production of halogenoalkanes?

Answer 24

• Further substitution reactions may occur
• Mixture of wanted and unwanted products form
• Have to undergo further separation processes

Question 25

What is reformation?

Answer 25

Reformation is the process of converting straight chain alkanes to branched chain or cyclic alkanes using a platinum catalyst.