Alcohols

Question 1

How are alcohols produced

Answer 1

Industrially by the hydration of alkenes in the presence of a catalyst

Question 2

state the conditions for forming alcohols

Answer 2

Essential Conditions
high temperature 300 °C
high pressure 70 atm
strong acidic catalyst of conc H3PO4

Question 3

How is ethanol produced?

Answer 3

Fermentation of glucose

Question 4

What are the conditions for the fermentation of glucose and why are they used?

Answer 4

Yeast
No air
temperatures 30-40C

At lower temperatures the reaction is too slow.
At higher temperatures the yeast dies and the enzymes denature.
Fermentation is done in an absence of air because the presence of air can cause extra reactions to occur- It oxidises the ethanol produced to ethanoic acid (vinegar).

Question 5

write equations to support the statement that ethanol produced by fermentation is a carbon neutral fuel

Answer 5

Removal of CO2 by photosynthesis
6CO2 + 6H2O➜ C6H12O6 + 6O2
Production of CO2 by fermentation and combustion
C6H12O6 ➜ 2CH3CH2OH + 2CO2
2CH3CH2OH + 6O2➜ 4 CO2 + 6 H2O

*NO NET RELEASE OF CO2

Question 6

discuss the environmental issues linked to decision making about biofuel use.

Answer 6

This does not take into account any energy needed to irrigate plants, fractionally distil the ethanol from the reaction mixture or process the fuel. If the energy for these processes comes from fossil fuels then the ethanol produced is not carbon neutral.

Question 7

What are alcohols classified into

Answer 7

Primary, secondary and tertiary alcohols

Question 8

What can primary alcohols be oxidised into

Answer 8

Aldehydes

Question 9

What can primary alcohols be further oxidised into

Answer 9

carboxylic acid

Question 10

What can secondary alcohols be oxidised into

Answer 10

ketones

Question 11

can tertiary alcohols be oxidised?

Answer 11

no - would requirea free C-C bond to break but there is non