1. Esterification and dehydration of alcohols
Keywords:
Esterification, elimination, ester, dehydration
Starter:
Use molecular models to make various alcohol molecules

2. A B C Learning Objectives
Model the esterification of alcohols with carboxylic acids B
Describe the elimination of H2O from alcohols to form alkenes. C
Name the esters formed by esterification reactions

3. Esterification – the reaction of an alcohol with a carboxylic acid to produce an ester and water Elimination – breaking up 1 molecule into 2 molecules Dehydration – an elimination reaction in which water is removed from a saturated molecule to make an unsaturated molecule

4. Esterification
An ester is formed when an alcohol is warmed with a carboxylic acid in the presence of an acid catalyst
The reaction is known as esterification
Concentrated sulfuric acid is often used as the acid catalyst

5. The esterification reaction between Propanoic acid and Methanol

6. In the reaction, the O-H bond in the alcohol is broken and water is formed. The water molecule comes from the OH of the carboxylic acid group and the H in the alcohol group

7. Naming esters X-yl X-anoate Alcohol Carboxylic acid
Choose an alcohol and a carboxylic acid card. Name the ester and draw its structure.

8. Esters are used as adhesives and solvents in the chemical industry
Esters are used as adhesives and solvents in the chemical industry. The flavours and fragrances of different esters are widely used to produce food flavourings and perfumes.

9. Place tube in a water bath (80C) for 5 mins
Preparing an ester
In a boiling tube add 1cm3 carboxylic acid to 1cm3 alcohol and add the catalyst (H2SO4)
Place tube in a water bath (80C) for 5 mins
Pour the product into a beaker of cold water
The oil on the surface will be the ester

10. Dehydration of an alcohol
An alcohol can be dehydrated to form an alkene in the presence of an acid catalyst (Conc phosphoric acid or conc sulphuric acid)
This is an elimination reaction
Alcohol is heated under reflux with the catalyst for 40 minutes.

11. The dehydration of cyclohexanol is seen below. What is the product?

12. Plenary
Pg 155
Questions 1, 2 and 3

13. Methanol
Methanoic acid
Ethanol
Ethanoic acid
Propanol
Propanoic acid
Butanol
Butanoic acid
Pentanol
Pentanoic acid
Hexanol
Hexanoic acid