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Esters. The smelly compounds. What are Esters?. A group of compounds that are responsible for some natural and synthetic flavours They are often found in ice-creams, lollies, flowers, perfumes and fruits. What are esters?. Some contain small molecules.
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Esters The smelly compounds
What are Esters? • A group of compounds that are responsible for some natural and synthetic flavours • They are often found in ice-creams, lollies, flowers, perfumes and fruits.
What are esters? • Some contain small molecules. • Predict the boiling point and volatility of small esters from this information.
What are esters? • Small esters ability to evaporate easily allows them to reach your nose! • Larger esters are oils and waxes.
How are Esters made? • Condensation reaction • This is between a carboxylic acid and an alcohol • It produces an ester and water
carboxylic acid + alcohol ester + water -COOH + -OH -COO + H20 The functional group of an ester is -COOH
Condensation Example: C2H3OOH + C2H5OH CH3COOCH2CH3 + H2O Ethanoic acid + ethanol ethyl ethanoate + water The OH from the alcohol and the H from the OH on the carboxylic acid break away to form water. The affected carbons from the alcohol and the carboxylic acid join together and form the ester
Naming Esters • The name of the esters produced has 2 parts: • Derived from the name of the alcohol with -yl replacing –anol • Derived for the name of the carboxylic acid where –ic acid is replaced with –ate E.g. ethanol and ethanoic acid react to form ethyl ethanoate and water
Have a go! What is the name of the Ester that would be produced from the condensation of methanol and propanoic acid? Methyl propanoate
Have a go! What is the name of the Ester that would be produced from the condensation of butanol and heptanoic acid? Butyl heptanoate
Questions: • Write reactions to show the production of: Methyl ethanoate Ethyl propanoate • Write the equation for the formation of the following esters: • CH3COOCH2CH3 • CH3CH2COOCH2CH3