Alcohols

Question 1

What’s the functional group for alcohols?

Answer 1

OH

Question 2

What’s the general formula for alcohols?

Answer 2

CnH2n+1 OH

Question 3

What are the properties of alcohols?

Answer 3

• Flammable (complete combustion in air produces CO2 and H2O)
• Soluble (neutral pH)
• Oxidise to form carboxylic acids (-COOH functional group)
• React with reactive metals

Question 4

What are the uses for alcohols?

Answer 4

Fuels - they release lots of energy when burned (use spirit burner)
Solvents in industry - alcohols can dissolve things that water can’t (e.g. hydrocarbons and lipid compounds)

Question 5

Explain the production of ethanol

Answer 5

• Seeds contain carbohydrate STARCH
• Starch needs to be broken down into sugars
• Seeds are germinated (enzymes in seeds turn starch into sugars)
• Plant material containing sugars is mixed with water and yeast
  THEN CARRY OUT FERMENTATION…

Question 6

Explain the process of Fermentation for the production of ethanol

Answer 6

• Glucose produces ethanol and carbon dioxide
• This is done by the enzymes in the yeast, and 30’C temperatures in anaerobic conditions
• Distillation should then be carried out to remove the water (ethanol is in aqueous solution)

Question 7

What are the Pro’s and Con’s of Fermentation?

Answer 7

PRO’S: Low temperatures requires low amounts of energy, sugar used comes from plants which make it renewable
CON’S: Product is aqueous solution of ethanol and water, so we need to purify using distillation which requires energy

Question 8

What are organic molecules?

Answer 8

Organic molecules have a framework of carbon atoms to
which hydrogen and other atoms are attached.

Question 8

What’s the formula for methanol?

Answer 8

CH3OH

Question 9

What’s the word equation for the complete combustion of ethanol?

Answer 9

ethanol + oxygen –> carbon dioxide and water

Question 10

Why does fermentation have to be anaerobic?

Answer 10

The ethanol would react with the oxygen to form a carboxylic acid (vinegar)