How are the element oxygen and sulphur detected in an organic compound?

The most commonly occurring elements in organic compounds are carbon, hydrogen, oxygen, nitrogen, sulphur and halogen elements. There is no direct method for the detection of oxygen. For detecting nitrogen, sulphur and halogens, we can use the sodium fusion test (Lassaigne’s test).

How will you detect the presence of nitrogen and sulphur in an organic compound?

Lassaigne’s test is the general test for the detection of halogens, nitrogen and sulphur in an organic compound. In order to detect them, these have to be converted into their ionic forms.

How can you detect the presence of sulfur in a compound using the Lassaigne test?

To confirm the presence of sulphur in a mixture, its sodium fusion extract is prepared. If sulphur is present, when sodium extract is made, it forms sodium sulphide, which when reacted with lead acetate we get a black precipitate of lead sulphide. The formation of black precipitate confirms the presence of sulphur.

How do you detect sulphur element?

Crush the contents with a glass rod and heat to boiling. Remove the insoluble matter by filtration. The filtrate is called Lassaigne’s extract. Nitrogen, sulphur and halogens present in an organic compound are detected by making use of Lassaigne’s extract.

How is oxygen detected in an organic compound?

Oxygen in compounds of carbon, hydrogen, and oxygen can be determined by heating the sample with an excess of strontium oxide and graphite in. Carbon in organic compounds can be determined by heating the sample with barium nitrate, and subsequently determining carbonate in the mixture.

What other tests are used to detect the presence of halogens in an organic sample?

Presence of halogen in organic compounds can be detected using:

• A. Liebig’s test.
• B. Duma’s test.
• C. Kjeldahl test.
• D. Beilstein test.

How is sulphur detected using the sodium fusion extract of the given organic compound?

The presence of sulphur can be identified by the precipitation of Lead Ethanoate or Sodium Nitroprusside. The presence of sulphur can be indicated if there is a black precipitate of lead sulphide. This can be done when the clean fusion solution is added to the diluted Acetic acid, producing a lead acetate solution.

Which of the following complex formation indicates presence of sulphur in the organic compound when sodium nitroprusside is added to sodium extract of the compound?

Detection of Sulphur During the preparation of Lassaigne’s extract, sulphur from the organic compound reacts with sodium to form sodium sulphide. It gives a purple colour with sodium nitroprusside due to the formation of sodium thionitroprusside.

How much sulphur is present in an organic compound?

Percentage of sulphur = (32×1.158×100)/(233×0.53)=30\%

How can you detect sulphur color?

ii) Sulphur can also be detected by adding lead acetate to SFE, acidified with acetic acid. The formation of a black precipitate (PbS) indicates the presence of sulfur.