Alcohols

Question 1

What are the conditions for the direct hydration of ethene?

Answer 1

Conc. phosphoric acid catalyst
300*C
6500kPa
Continuous process

Question 2

Direct hydration of ethene produces a low yield. How can you increase the yield?

Answer 2

Recycling unreacted ethene several times

Question 3

What are the raw materials needed for the direct hydration of ethene?

Answer 3

Ethene (from crude oil)

Question 4

What are the conditions for the industrial fermentation of ethene?

Answer 4

Enzymes from yeast
35*C
Limited oxygen
Batch process

Question 5

What is an advantage and disadvantage of using industrial fermentation rather than direct hydration to produce ethene?

Answer 5

Ad- more cost efficient

Disad - slow process

Question 6

What are biofuels?

Answer 6

The fuels made from a renewable biological source

Question 7

If you partially oxidise a primary alcohol what is produced?

Answer 7

An aldehyde

Question 8

If you fully oxidise a primary alcohol what is produced?

Answer 8

A carboxylic acid

Question 9

How do you get an aldehyde from a primary alcohol?

Answer 9

Partially oxidise. If you use an excess of alcohol and distil off the aldehyde as soon as it forms. Separates from oxidising agent

Question 10

How do you get a carboxylic acid from a primary alcohol?

Answer 10

Fully oxidise
Alcohol heated under reflux with an excess of the oxidising agent
Carboxylic acid distilled off once the reaction is complete

Question 11

Why, when making in aldehydes, is the product distilled off as soon as it forms?

Answer 11

To remove it from the oxidising agent to prevent it from being oxidised further into a carboxylic acid

Question 12

How are alcohols produced industrially?

Answer 12

The hydration of alkenes in the presence of an acid catalyst

Question 13

What is the name of the reaction whereby alcohols are converted to alkenes?

Answer 13

Elimination reaction

Question 14

What is a suitable catalyst for the elimination reaction of alcohols to produce alkenes?

Answer 14

Hot concentrated sulphuric acid

Question 15

What can the product of an elimination reaction of alcohols be used for?

Answer 15

Can supply alkene monomers for polymerisation from a renewable raw material

Question 16

Describe and explain the elimination mechanism

Answer 16

A strong acid catalyst adds a proton (H+) to the OH group to create water and a better leaving group
As this group leaves, a C=C bond can form along with the loss of an H+ to regenerate the catalyst

Question 17

What is a suitable oxidising agent?

Answer 17

Acidified potassium dichromate (VI)

Question 18

What are secondary alcohols oxidised to?

Answer 18

Ketones