iGCSE Alcohols

The catalyst in the production of ethanol from ethene and steam is

• potassium dichromate (VI)

• phosphoric acid

• enzymes in yeast

• dilute sulfuric acid

The optimum temperature for the fermentation of glucose to produce ethanol is

• 50C

• 15C

• 30C

• 100C

An advantage of producing ethanol by fermentation rather than hydration of ethene is that you use lower temperature and pressure, so ____ energy is needed.

Fermentation needs to be anaerobic or else the following would be formed instead of ethanol:

• water and carbon dioxide

• hydrogen and carbon dioxide

• water and oxygen

• carbon dioxide

Ethanol is made by reacting ethene with steam in the presence of a phosphoric acid catalyst.

Which row gives the correct conditions of temperature and pressure for this reaction?

• Temp: 35C

  Pressure: 300 atmospheres

• Temp: 65C

  Pressure: 300 atmospheres

• Temp: 300C

  Pressure: 65 atmospheres

• Temp: 300C

  Pressure: 35 atmospheres

The functional group for carboxylic acids is:

• H⁺

• C-C

• -OH

• -COOH

Ethanol can be manufactured by the fermentation of a solution of glucose.

Complete the word equation for this reaction.

glucose --> ethanol + ______ _______

What are the two conditions required for the fermentation of glucose to produce ethanol?

• room temperature

  1 atmosphere

• 30C

  absence of air

• 300C

  65 atmospheres

• 65C

  yeast

Ethanol can be oxidised to produce a carboxylic acid.

Give the names of the two reagents used in this oxidation reaction.

• glucose

  yeast

• alkane

  chlorine

• potassium dichromate (VI)

  dilute sulfuric acid

• ethene

  steam

Ethanol can be oxidised to produce a carboxylic acid using acidified potassium dichromate (VI).

This is the colour change for the reaction:

• green to orange

• orange to green

• orange to colourless

• colourless to orange