Making and using alcohol Keywords: Hydration, catalyst, fermentation, ethanol, methanol Starter: Write the equation for the hydration of ethene Include necessary conditions

A B C Learning Objectives Compare the efficiency of methods used to make ethanol B Describe the industrial production of ethanol from both sugars and ethene C Outline the uses of ethanol and methanol

The hydration of ethene Ethanol is manufactured industrially by the catalytic hydration of ethene using steam in the presence of phosphoric acid catalyst

The hydration of ethene is reversible so conversion of ethene is incomplete. Each time the reagents pass through the reactor, only 5% of the ethene is converted into ethanol. Any unreacted gases are recycled and passed through the reactor again. Overall 95% conversion is achieved

In the fermentation of alcohol, carbohydrates are converted into ethanol and carbon dioxide. Sugar or starch is usually used as the carbohydrate source Ethanol solution produced in this way has a concentration of up to 14% alcohol by volume (ABV)

Fermentation reactions are slow at temperatures below 25C, while at temperatures above 37C the enzyme starts to denature and lose its efficiency Fermentation is carried out in solution at relatively low temperatures, in the presence of yeast. The reaction is catalysed by an enzyme in the yeast called zymase

The toxicity of the alcohol limits the concentration of ethanol that can be made by fermentation. This is because the enzyme ceases to function above an alcohol concentration of 14% Fermentation of carbohydrates to ethanol is anaerobic (it does not require oxygen). It is therefore important that fermentation is carried out in the absence of air. Such conditions prevent the oxidisation to undesirable compounds such as ethanal or ethanoic acid, which would affect the flavour of the product

How much units is recommended a day for you? Draw a graph to compare the ABV of these alcoholic beverages

Plenary Write down 2 things you have learned this lesson on one side of the card and 1 question about the lesson on the other side Homework: Research the uses of alcohol (specifically ethanol and methanol. Produce a short report or poster

1. Name the 2 chemical processes that can be used to make ethanol 2. Write the balanced symbol equation for the hydration of ethene (include conditions) 3. What is the percentage conversion of ethene to ethanol? How is this conversion achieved? 4. Write the balanced symbol equation for the fermentation of ethanol from carbohydrates 5. IN terms of alcohol, what does ABV stand for? 6. Describe the conditions needed for fermentation of ethanol 7. Explain the importance of the conditions used during fermentation 8.What are the uses of ethanol and methanol?