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Question
Esters are sweet-smelling substances and are used in making perfumes. Describe an activity for the preparation of an ester with the help of a well labelled diagram. Write an equation for the chemical reaction involved in the formation of the ester. Also write the names of all the substances involved in the process of esterification.
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Solution
Esters are sweet-smelling substances which are used to make perfumes. The process in which a carboxylic acid reacts with an alcohol to form an ester is called esterification.
An ester is formed when ethanol (alcohol) reacts with ethanoic acid, on heating, in the presence of a few drops of concentrated sulphuric acid. The name of the ester formed is ethyl ethanoate.
Let's prepare an ester.
(1) In a test tube, take 1 ml of ethanoic acid and add some ethanol to it along with a few drops of concentrated sulphuric acid.
(2) Warm the test tube in a beaker, containing hot water, for 5 minutes.
(3) Take about 50 ml of water in another beaker and pour the contents of the test tube into it. When you smell it, a sweet fragrance is obtained indicating the formation of an ester.
The diagrammatic representation of the above process is as follows:
The chemical equation involved in the formation of ester is as follows:
`CH_3 COOH + C_2 H_5 OH` 
`CH_3 COOC_2 H_5 + H_2 O`
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RELATED QUESTIONS
A student adds a spoon full of powdered sodium hydrogen carbonate to a flask containing ethanoic acid. List two main observations, he must note in his note book, about the reaction that takes place. Also write chemical equation foe the reaction.
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(a) C5H10O2
(b) C6H12O2
(c) C7H14O2
(d) C8H16O2
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What do you notice when acetic acid reacts with metals?
What do you notice when acetic acid reacts with alkalies?
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On adding 2 mL acetic acid to 2 mL of water in a test tube, it was observed that
(A) a clear and transparent solution is formed
(B) a white precipitate is formed almost immediately
(C) two separate layers were formed
(D) a colourless and odourless gas is evolved
Explain the following term with an example.
Oxidant
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Ethene to acetic acid
State how the following conversions can be carried out:
Ethyl alcohol to Ethane
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Ethyne is more reactive than ethane
Give balanced chemical equations for the following conversion :
Ethanoic acid to ethyl ethanote
Identify the term or substance based on the descriptions given below:
Ice like crystals formed on cooling an organic acid sufficiently.
Assertion (A): Esterification is a process in which a sweet-smelling substance is produced.
Reason (R): When esters react with sodium hydroxide an alcohol and sodium salt of carboxylic acid are obtained.
Which of these is not an organic acid?
The reaction between acetic acid and sodium carbonate is shown in the following figure.
Answer the questions with the help of a diagram.
- Which gas does come out as effervescence in the big test tube?
- What is the colour change in the lime water present in the small test tube?
- Write the related reaction.
Give the balanced chemical equation of the following reaction:
Neutralization of NaOH with ethanoic acid.
