Alcohol - Uses

Question 1

How is ethanol produced?

6

Answer 1

By fermentation

Fruits such as grapes contain the sugar glucose, C6H12O6

When yeast is added, the sugar forms a solution of ethanol and carbon dioxide

C6H12O6—yeast–>2C2H5OH + 2CO2

Glucose —yeast–> Ethanol + carbon dioxide

Yeast is a micro-organism that contains an enzyme called zymase which catalyses the above reaction

Question 2

What is the chemical formula for glucose?

Answer 2

C6H12O6

Question 3

What is the chemical formula for ethanol?

Answer 3

C2H5OH

Question 4

What enzyme is found in yeast which catalyses the fermentation of glucose into ethanol and carbon dioxide?

Answer 4

Zymase

Question 5

What is the concentration of ethanol in wines?

Answer 5

About 10-12% v/v

Question 6

Why is it impossible to create alcoholic drinks with an ethanol % v/v over 12% by fermentation?

Answer 6

Once the ethanol content reaches this level, it kills the yeast and fermentation is stopped

Question 7

What is the concentration of ethanol in beers and cider?

Answer 7

4-5% v/v

Question 8

How can alcoholic drinks with a percentage v/v over 12 be achieved?

Answer 8

To produce drinks of higher alcohol concentration, fermented liquids are distilled

Question 9

What is formed when wine is distilled?

Answer 9

It produces brandy

Question 10

What alcoholic drinks can be formed through distillation?

Answer 10

Spirits such as whiskey, gin, vodka and brandy

Question 11

What is the ethanol % v/v of distilled drinks?

Answer 11

About 40% v/v

Question 12

What alcohol is particularly toxic?

Answer 12

Methanol

Question 13

What is added into industrial alcohol to prevent people dinking it?

Answer 13

Methanol

Question 14

Why is methanol added into industrial alcohol?

Answer 14

To prevent people drinking it

Question 15

What is methanol added into to prevent people drinking it?

Answer 15

Industrial alcohol

Question 16

What is the addition of methanol to industrial alcohol called?

Answer 16

Denaturation

Question 17

What is methanol referred to as when it is added to industrial alcohol to prevent people drinking it?

Answer 17

It is referred to as a denaturing agent

Question 18

What is the combination of methanol and industrial alcohol called?

Answer 18

Methylated spirits

Question 19

Describe the composition of methylated spirits.

Answer 19

It is 90% ethanol and 10% methanol

Question 20

What is often added to methylated spirits as a warning?

Answer 20

Purple dye

Question 21

What can drinking methanol lead to?

Answer 21

Blindness and death

Question 22

What can excess ethanol consumption cause?

2

Answer 22

It can cause unconsciousness and vomiting

It can lead to death as a result of drowning in vomit as well as liver failure

Question 23

How does ethanol slow one’s reaction time?

Answer 23

Ethanol is a drug that depresses the activity of the central nervous system

Question 24

Ethanol is a drug that depresses the activity of the central nervous system, what affects does this have?
(3)

Answer 24

It slows reaction time

It makes us less vigilant

It impairs our judgement

Question 25

What is the legal limit of ethanol per 100 cm3 of blood?

Answer 25

The legal limit is 20mg per 100cm3 of blood

Question 26

What is the only commonly used drug that is sufficiently volatile to pass from the blood to the air in the lungs?

Answer 26

Ethanol

Question 27

How can ethanol concentration in the blood be measured?

2

Answer 27

Ethanol is the only commonly used drug that is sufficiently volatile to pass from the blood to the air in the lungs

Hence, a measurement of the ethanol concentration in one’s breath gives an indication of the concentration of alcohol in the blood

Question 28

Other than in alcoholic drinks, what are the main uses of ethanol?
(2)

Answer 28

It can be used as a fuel

It can be used as a solvent

Question 29

Give some examples of where ethanol can be used as a solvent.
(7)

Answer 29

Perfumes

After-shave lotions

Deodorants

Hair sprays

Polishes

Varnishes

Dyes