What is the purpose of adding phosphoric acid in the synthesis of aspirin?

Phosphoric acid acts as a catalyst to accelerate the reaction. (Catalyst is a substance that can be added to a reaction and helps speed up the reaction without getting caught in the process.

What is the purpose of adding water after you react salicylic acid with acetic anhydride?

The mixture is heated to form the acetylsalicylic acid (C9H8O4) and acetic acid (C2H4O2). After the reaction takes place, water is added to destroy the excess acetic anhydride and cause the product to crystallize.

What is the purpose of sulfuric acid or phosphoric acid used in the acetylation reaction?

The purpose of the sulfuric acid or phosphoric acid in the acetylation reaction is to act as a catalyst.

Why is the synthesized aspirin in the laboratory Cannot be used for commercial and pharmaceutical purposes?

In this laboratory activity you will synthesize aspirin, a derivative of salicylic acid. Salicylic acid and its derivatives are antipyretics. Salicylic acid itself is not used for these purposes because it has an irritating effect on the stomach. The most common salicylate used in medicine today is aspirin.

What is the purpose of the phosphoric acid added after the acetic anhydride?

Concentrated phosphoric acid will be used to keep everything in the acidified, protonated state. Acetic anhydride is the preferred acid derivative to synthesize aspirin commercially because the acetic acid produced in this reaction can be used again, by converting it back into acetic anhydride.

Why do we use acetic anhydride instead of acetic acid?

Acetyl chloride and acetic anhydride are often used instead of acetic acid because they are more reactive and give better yields of product.

How does salicylic acid react with acetic anhydride?

Salicylic acid interacts with acetic anhydride in presence of few drops of concentrated sulphuric acid to produce aspirin and a molecule of acetic acid.

What is the purpose of the concentrated phosphoric acid used in the first step?

The concentrated phosphoric acid was used as a catalyst; it was added to increase the rate of the reaction between salicylic acid and acetic anhydride.

Why is sulfuric acid added to salicylic acid and acetic anhydride?

The purpose of adding sulphuric acid (catalyst) is to aid and augent the process of detaching the acetate ion (CH3COO–) from acetic anhydride which ultimately gets associated with H+ ion from phenolic hydroxy group in salicylic acid to be eliminated as a mole of acetic acid.

What is the purpose of using sulfuric acid in this experiment?

Reaction of sulfuric acid and H₂O When conducting chemical experiments, one must always add sulfuric acid to water, not the other way around. Sulfuric acid is a strong dehydrating substance, and concentrated sulfuric acid forces water out of various compounds. It is often used as a drying agent.

Why is acetic anhydride used instead of acetic acid in the synthesis of aspirin?

Acetic anhydride is the preferred acid derivative to synthesize aspirin commercially because the acetic acid produced in this reaction can be used again, by converting it back into acetic anhydride. (Avoid breathing any of the vapors, which contain acetic acid, and are irritating).

Why might your synthesized aspirin be less pure than the commercial aspirin products?

The synthesis reaction of aspirin is shown below: Since acetic acid is very soluble in water, it is easily separated from the aspirin product. If impurities are present in your crude sample, the melting point range for your product will be lower than the range of pure aspirin.

Why does acetic anhydride need heat to work?

It doesn’t work too quickly though, so the heat is needed to speed it up. The acetic anhydride essentially ends up transferring its acetyl group to 2-hydroxybenzoic acid. The mechanism is as follows:

Why is acetic anhydride a good leaving group in aspirin?

Because acetyl salicylic acid, aka Aspirin, has an acetate group, and acetic anhydride has one that is a good leaving group.

How do you get rid of acetic anhydride?

As a result, it’s easy to get rid of all the acetic anhydride when you’re done with it. It makes cleaning up easier, because although acetic anhydride is actually quite hazardous, dilute acetic acid is pretty harmless, and it’s generally easy to find DI water nearby to further dilute the acetic acid if necessary.

How do you make acetic anhydride and sulphuric acid?

Add 8.5 ml acetic anhydride and 3-4 drops of concentrated sulphuric acid to the flask carefully and mix thoroughly. Warm the mixture on water bath at 60 degrees about 20 min with frequent stirring. Allow the contents in the flask to cool and pour into 100 ml cold water in 250 ml beaker with constant Stirring.