LECTURE 2: ALCOHOLS

Question 1

Are alcohols polar or non-polar

Answer 1

polar

Question 2

Why do alcohols have a higher BP than alkanes of similar mass?

Answer 2

• polar -OH group, stronger h-bond
• alkanes only have weak dispersion forces

Question 3

Justify the solubility of alcohols

Answer 3

• higher solubility than alkanes
• strong H-bonds with water (also polar)
  -dissolves via dipole-dipole or H-bonding

Question 4

Why are alcohols soluble in non-polar solvents?

Answer 4

hydrophobic end interacts with non-polar molecule (not the -OH bit)
- dissolves via dispersion forces

Question 5

What is the catalyst for an addition reaction of an alcohol?

Answer 5

dilute H+

Question 6

What happens when an asymmetrical alkene is hydrated?

Answer 6

in the presence of dilute H+, two alcohols are produced

Question 7

Qualitatively and quantitatively describe the process of fermentation

Answer 7

sugars + yeast = fermentation (alcohol + CO2)

C6H12O6 (aq) (yeast)/ 2C2H5OH (aq) +2CO2(g) + heat

Question 8

What functional group do aldehydes have

Answer 8

C=O bonded to a H atom at the end of chain

Question 9

suffix for aldehydes

Answer 9

-al

Question 10

whats the difference between aldehyde and ketone

Answer 10

its the same C=O but aldehydes have it bonded on the end carbon whereas ketones can have it anywhere in the chain

Question 11

suffix for ketone

Answer 11

-one

Question 12

dehydration reaction of alcohol

Answer 12

concentrated H2SO4, copy paste, put a double bond, +H2O

Question 13

substitution reaction with hydrogen halide

Answer 13

alcohol + halide –> R–X +H2O

(if the halide is HCL, the catalyst is ZnCl2)

Question 14

redox

Answer 14

oxidation - gain oxygen, lose hydrogen
reduction - gain hydrogen, lose oxygen

Question 15

what is the catalyst used in oxidation reaction

Answer 15

acidified potassium dichromate - K2Cr2O7

Question 16

Secondary alcohols are oxidised to…?

Answer 16

ketones