Phenols do not respond to which of these tests?a)Schiff’s reagent testb)FeCl3testc)Br2water testd)Litmus testCorrect answer is option 'A'. Can you explain this answer?

Question

Phenols do not respond to which of these tests?a)Schiff&#8217;s reagent testb)FeCl3testc)Br2water testd)Litmus testCorrect answer is option 'A'. Can you explain this answer?

Answer

Phenols respond to all the above mentioned tests except Schiff’s reagent test, which is shown by aldehydes.

Answer

Schiffs reagent test is shown by aldehydes...phenols doesn't respond to this test

Answer

Bcz  its use as a qualitative test for aldehydes, the unknown sample is added to the decolorized Schiff reagent; when aldehyde is present a characteristic magenta color develops. Schiff-type reagents are used for various biological tissue staining methods, e.g. Feulgen stain and periodic acid-Schiffstain.

Answer

Phenols are a class of organic compounds that contain a hydroxyl (-OH) group attached directly to an aromatic ring. They are characterized by their acidic properties due to the presence of the hydroxyl group. Phenols can undergo various chemical reactions and tests to determine their presence or identify specific functional groups attached to the aromatic ring. However, there are certain tests that phenols do not respond to, and one of them is the Schiff's reagent test.

Schiff's reagent is a solution of fuchsin acid, which is a dye that can react with primary amines to produce a colored compound. The test involves adding Schiff's reagent to the compound and observing if a color change occurs. If the compound contains a primary amine, a pink to purple color is formed. However, phenols do not contain primary amines and therefore do not respond to Schiff's reagent test.

To further understand why phenols do not respond to Schiff's reagent test, let's explore the other tests that phenols do respond to:

FeCl3 test:
- Phenols react with ferric chloride (FeCl3) to form a colored complex. This test is commonly used to distinguish phenols from other compounds. When FeCl3 is added to a phenol, a color change from colorless to purple, green, or blue occurs, depending on the specific phenolic compound.

Br2 water test:
- Phenols react with bromine water (Br2 water) to form a white precipitate. This test is used to confirm the presence of phenols in a compound. When Br2 water is added to a phenol, a white precipitate of 2,4,6-tribromophenol is formed.

Litmus test:
- Phenols are acidic in nature due to the presence of the hydroxyl group. When phenols are dissolved in water, they turn blue litmus paper red, indicating their acidic properties.

In summary, phenols do not respond to the Schiff's reagent test because they do not contain primary amines. However, they do respond to other tests such as the FeCl3 test, Br2 water test, and litmus test due to their acidic nature and ability to form colored complexes or precipitates.

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