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formaldehyde reacts with oxidised indole ring to give coloured complex .mercuric sulphate in sulphuric acid acts as the oxidising agent

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What is the principle of heat coagulation test for proteins?

The principle of the heat coagulation test for proteins is based on the denaturation and coagulation of proteins when exposed to heat. By heating a solution containing proteins, the proteins unfold and aggregate, forming a visible clot or precipitate. This test is commonly used to assess the presence of specific proteins by noting the formation of a clot or precipitate upon heating.


What test is used to show the reducing property of an aldehyde and a ketone?

The Tollens' test is commonly used to show the reducing property of an aldehyde. In this test, an aldehyde will reduce silver ions in Tollens' reagent to form a silver mirror. Ketones do not show this reaction.


What substances give a positive tollens test?

When adding the aldehyde or ketone to Tollens' reagent, the test tube is put in a warm water bath. If the reactant under test is an aldehyde, Tollens' test results in a silver mirror. If the reactant is a ketone, it will not react because a ketone cannot be oxidized easily. A ketone has no available hydrogen atom on the carbonyl carbon that can be oxidized - unlike an aldehyde, which has this hydrogen atom.


What is the principle of tollen's test for aldehydes?

The reagent is reduced to metallic silver by aldehydes, which in turn are oxidized to the corresponding acides. Silver deposits at the bottom of the test tube as a mirror. - U of Toronto chm lab manual =>both aliphatic and aromatic aldehydes are form silver mirror but ketones not.


Is vanillin positive in DNPH test?

No, vanillin is not positive in the DNPH (2,4-dinitrophenylhydrazine) test. The DNPH test is used to detect the presence of carbonyl (aldehyde or ketone) functional groups in compounds and vanillin does not contain a carbonyl group.

Related Questions

What is the name of the test for proteins?

The test for proteins is called the Biuret test. This test is based on the principle that proteins react with copper sulfate in an alkaline solution to produce a violet color.


What is the principle of heat coagulation test for proteins?

The principle of the heat coagulation test for proteins is based on the denaturation and coagulation of proteins when exposed to heat. By heating a solution containing proteins, the proteins unfold and aggregate, forming a visible clot or precipitate. This test is commonly used to assess the presence of specific proteins by noting the formation of a clot or precipitate upon heating.


What test is used to show the reducing property of an aldehyde and a ketone?

The Tollens' test is commonly used to show the reducing property of an aldehyde. In this test, an aldehyde will reduce silver ions in Tollens' reagent to form a silver mirror. Ketones do not show this reaction.


What is principle of schiffs test?

The Schiff's reagent, which is a mixture of fuchsin-sulfurous acid, is used to detect the presence of aldehydes or compounds with free aldehyde or ketone groups in a sample. When the reagent reacts with the aldehyde group, it forms a magenta-colored complex due to the reduction of the fuchsin dye. This color change is the basis of the Schiff's test, indicating the presence of aldehydes in the sample.


Principles of colour reaction of protein?

1. biuret test 2. xhenthoproteic test 3. millon's test 4. Cole's aldehyde test 5. sakaguchi test 6. lead acetate test 7. ninhydrin test 8. gram negative bacteria test 9. phenolphthalein test


How you test if foods have proteins?

The Biuret test allows one to test for proteins.


What substances give a positive tollens test?

When adding the aldehyde or ketone to Tollens' reagent, the test tube is put in a warm water bath. If the reactant under test is an aldehyde, Tollens' test results in a silver mirror. If the reactant is a ketone, it will not react because a ketone cannot be oxidized easily. A ketone has no available hydrogen atom on the carbonyl carbon that can be oxidized - unlike an aldehyde, which has this hydrogen atom.


What is the principle of tollen's test for aldehydes?

The reagent is reduced to metallic silver by aldehydes, which in turn are oxidized to the corresponding acides. Silver deposits at the bottom of the test tube as a mirror. - U of Toronto chm lab manual =>both aliphatic and aromatic aldehydes are form silver mirror but ketones not.


What are the principles involved in xanthoproteic test?

The xanthoproteic test is a test for the detection of proteins. If proteins are present, concentrated nitric acid reacts with the proteins to form a yellow color that turns orange-yellow by the addition of alkali. This is called the xanthoproteic reaction.


Is vanillin positive in DNPH test?

No, vanillin is not positive in the DNPH (2,4-dinitrophenylhydrazine) test. The DNPH test is used to detect the presence of carbonyl (aldehyde or ketone) functional groups in compounds and vanillin does not contain a carbonyl group.


Why pyrrole-2-aldehyde does not respond to tollens reagent?

Pyrrole-2-aldehyde does not respond to Tollens reagent because it is not a reducing sugar. Tollens reagent (silver nitrate) is used to test for the presence of aldehyde groups, which are commonly found in reducing sugars. Reducing sugars contain aldehyde groups and are capable of donating electrons to Tollens reagent, forming a silver mirror on the test tube wall. Pyrrole-2-aldehyde does not contain aldehyde groups, and therefore is not a reducing sugar. As a result, it does not react with Tollens reagent.


What is the equation for the reaction of modified furter-meyer test?

The reaction for the modified Fehling's test involves the oxidation of an aldehyde to a carboxylic acid in the presence of copper(II) ions. This reaction results in the formation of a brick-red precipitate of copper(I) oxide, which indicates a positive test for the presence of an aldehyde group.