2.7 Alcohols and Carboxylic acids

Question 1

Describe what conditions are needed for the hydration of ethene:

Answer 1

1. 300 degrees (Forward reaction is exothermic, therefore a low temperature would achieve a higher yield, however this gives a slower rate of reaction so there must be a compromise)
2. 60-70 atmospheres (two to one moles of gas so a high yield is favoured by high pressure, however equipment is expensive to carry higher pressure)
3. Catalyst= phosphoric acid

Question 2

Describe the advantages of using biofuels:

Answer 2

1. Renewable= plants can be grown each year
2. Carbon neutral?= overall the carbon dioxide produced is lower than burning fossil fuels as plants take it in through photosynthesis
3. Economic security= countries that do not have fossil fuels as a natural resource are less dependant on changes in price and availability

Question 3

Describe the disadvantages of using biofuels:

Answer 3

1. Land use= Land that is used to produce plants for biofuels cannot be used to produce food
2. Use of resources= growing the necessary crops require farming resources like water which can strain local resources
3. Carbon neutrality?= the factories needed to make biofuels and transport will use alot of fuel which isnt carbon neutral

Question 4

What is a dehydrating agent used to dehydrate alcohol?

Answer 4

concentrated sulfuric acid or heated aluminium oxide

Question 5

Give the summary of oxidation reactions:

Answer 5

1. Primary-> aldehydes-> carboxylic acids
2. Secondary-> ketones
3. Tertiary-> not oxidised

Question 6

What is the colour change to test for primary, secondary, tertiary alcohols? What agent is used to test these?

Answer 6

agent= Acidified potassium dichromate
Colour change= orange to green

Question 7

What is the catalyst used in esterification?

Answer 7

Concentrated sulfuric acid