Reactions of alcohols

Question 1

What is the equation for the combustion of ethanol?

Answer 1

C₂H₅OH(l) + 3O₂(g) —–> 2CO₂(g) + 3H₂O(l)

Question 2

What is an elimination reaction?

Answer 2

A reaction where a small molecule leaves a larger molecule it was previously bonded to

Question 3

What type of reaction is the elimation of alcohols?

Answer 3

dehydration

Question 4

What group is lost from the alcohol molecule in a dehydration reaction?

Answer 4

Water

Question 5

What are the 2 products of a dehydration reaction?

Answer 5

An alkene and water

Question 6

What are the 2 ways an alcohol can be dehydrated?

Answer 6

1. Excess hot sulphuic acid
2. Passing their vapours over heated aluminium oxide

Question 7

Why may it be considerred more environmentally friendly to produce alkenes/polymers through the elimination of alcohols?

Answer 7

Addition polymers can be produced without deriving monomers from crude oil

Question 8

Is the combustion of ethanol an elimination or oxidation reaction?

Answer 8

Oxidation

Question 9

What are primary alcohols oxidised into?

Answer 9

Aldehydes

Question 10

What are aldehydes further oxidised into?

Answer 10

Carboxylic acids

Question 11

What are secondary alcohols oxidised into?

Answer 11

Ketones

Question 12

Why can’t tertiary alcohols and ketones be oxidised easily?

Answer 12

Oxidation of these molecules would need a C-C bond to break rather than a C-H

Question 13

What is a suitable oxidising agent for the oxidation of ethanol?

Answer 13

Potassium dichromate acidified with sulfuric acid

Question 14

In the oxidation of alcohols do aldehydes act as oxidising or reducing agents?

Answer 14

Reducing

Question 15

What is observed if an alcohol is oxidised?

Answer 15

Colour change from orange to green