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प्रश्न
Explain the following reaction with an example.
Saponification
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उत्तर
When an ester is heated with dilute sodium hydroxide (an alkali) solution, it gets converted back to the original alcohol and sodium salt of the original carboxylic acid. Such a reaction is known as saponification.
\[\ce{Ester + Sodium hydroxide ->[Heat] Sodium carboxylate + Alcohol}\]
E.g. Ethyl ethanoate and sodium hydroxide react to give sodium ethanoate and ethanol.
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संबंधित प्रश्न
A student puts a drop of reaction mixture of a saponification reaction first a blue litmus paper and then on a red litmus paper. He may observe that:
(a) There is no change in the blue litmus paper and the red litmus paper turns white.
(b) There is no change in the red litmus paper and the blue litmus paper turns red.
(c) There is no change in the blue litmus paper and the red litmus paper turns blue.
(d) No change in colour is observed in both the litmus papers
In order to study saponification reaction, we first prepare 20% solution of sodium hydroxide. If we record the temperature of this solution just after adding sodium hydroxide flakes to water and also test its nature using litmus, it may be concluded that the process of making this solution is
(A) exothermic and the solution is alkaline
(B) endothermic and the solution is alkaline
(C) endothermic and the solution is acidic
(D) exothermic and the solution is acidic
How esters are prepared ?
Draw the structure for the following compound:
Propanoic acid
The organic acid present in vinegar is ______.
What type of compound is formed when a carboxylic acid reacts with an alcohol in the presence of conc. H2SO4?
On adding NaHCO3 to acetic acid, a gas is evolved which turns lime water milky due to the formation of:
(1) Calcium bicarbonate
(2) Calcium hydroxide
(3) Calcium carbonate
(4) Calcium acetate
Write the molecular formulae and structure formula of ethanic acid?
How will you carry out the following conversions?
Ethene to acetic acid
Fill in the blank with appropriate word/words.
Vinegar is a solution of about ________per cent ________in water.
State how the following conversions can be carried out:
Ethene to Ethyl alcohol.
Give reason for the following :
Ethyne is more reactive than ethane
Vinegar is a solution of ______.
Which of these is not an organic acid?
Draw the structural diagram of:
Ethanoic acid
Bubbles are seen in the test tube during the preparation of lime water.
Shristi heated Ethanol with a compound A in presence of a few drops of concentrated sulphuric acid and observed a sweet smelling compound B is formed. When B is treated with sodium hydroxide it gives back Ethanol and a compound C.
- Identify A and C
- Give one use each of compounds A and B.
- Write the chemical reactions involved and name the reactions.
Write the chemical equation for the following:
Saponification Reaction
A spatula full of sodium carbonate is taken in a test tube and 2 mL of dilute ethanoic acid is added to it.
Write a chemical equation for the reaction.
How is ethanol to ethanoic acid an oxidation reaction different from the reaction in which ethanol burns in the presence of oxygen?
