5: Alcohols

Question 1

What is the general formula for alcohols?

Answer 1

CnH2n+1

Question 2

If there are 2 or 3 OH groups in an alcohol, what will the suffix be?

Answer 2

Diol
Triol

Question 3

What is a primary alcohol?

Answer 3

An alcohol where the OH is attached to one carbon only.

Question 4

What is a secondary alcohol?

Answer 4

The carbon that the alcohol is attached to is bonded to 2 other carbons

Question 5

What is a tertiary alcohol?

Answer 5

An alcohol where the carbon that the OH is bonded to is bonded to 3 other carbons.

Question 6

How can we make alkenes from alcohols?

Answer 6

By eliminating water

Question 7

Name the reaction where water is eliminated from an alcohol to form alkenes.

Answer 7

Dehydration

Question 8

What conditions are needed for dehydration of alcohols?

Answer 8

Concentrated H2SO4 catalyst
Warm

Question 9

1. In dehydration, name the substance that attacks the lone pairs on oxygen.
   What charge does this give the oxygen?

Answer 9

H+
This gives the oxygen a positive charge.

Question 10

2. In dehydration, why does H2O break off?

Answer 10

The positive oxygen draws electrons from the carbon onto it, so H2O breaks off the alcohol.

Question 11

3. In dehydration, what type of molecule remains once the H2O breaks off?

Answer 11

Carbocation

Question 12

4. In dehydration, what atom does the carbocation lose to form an alkene?

Answer 12

H

Question 13

Why does dehydration of unsymmetrical alcohols lead to more than one product?

Answer 13

The double bond can go either side of the carbon that had the OH group on it.