Table of Contents
- 1 Why is it necessary to boil the sodium extract with hno3 before the detection of halogens?
- 2 Why do we boil the extract with concentrated hno3 in Lassaignes test for halogens?
- 3 Why is dilute HNO3 added to sodium extract?
- 4 What is the role of HNO3 in nitration of benzene?
- 5 Why Lassaigne extract is acidified?
- 6 Which of the following compound is added to the sodium extract before?
Why is it necessary to boil the sodium extract with hno3 before the detection of halogens?
Why is it necessary to boil the sodium extract with conc. HNO3 before testing the halogen? It is boiled with concentrated nitric acid to decompose any sodium cyanide or sodium sulphide present in the compound containing nitrogen or sulphur also.
Why do we boil the extract with concentrated hno3 in Lassaignes test for halogens?
Explanation: In case of Lassaigne’s test of halogens, it is necessary to remove sodium cyanide and sodium sulphide from the sodium extract if nitrogen and sulphur are present. This is done by boiling the sodium extract with conc. HNO3.
What is the role of conc hno3 in the detection of halogen?
Conc. HNO3 is added to sodium extract before adding silver nitrate for testing halogens, to decompose any NaCN or Na2S if present.
What is added to sodium extract before testing for halogens?
Why is nitric acid added to sodium extract before adding silver nitrate for testing halogens?
Why is dilute HNO3 added to sodium extract?
In the test of halogens from sodium extract, a small amount of dilute HNO3 is added. This is because in testing the halogen from the Lassigne’s extract, it contains halogens. Nitric acid decomposes sodium cyanide and sodium halide. else, they precipitate in test and misguide the result.
What is the role of HNO3 in nitration of benzene?
HNO3 acts as a base in the nitrating mixture and provides the electrophile NO2+ .
Which acid is used to acidify the sodium fusion extract in the test for Sulphur?
acetic acid
Test for Sulphur Na-extract is acidified by acetic acid and lead acetate is added to it. Black precipitate of lead sulphide is formed along with Sodium acetate.
Why do we prepare sodium fusion extract?
In order to detect the elements in organic compounds, they have to be converted into their ionic forms. This is done by fusing the organic compound with sodium metal. The extract is called sodium fusion extract or Lassaigne’s extract.
Why Lassaigne extract is acidified?
It has sodium sulfide in the extraction when the extraction is acidified with $C{H_3}COOH$ and on the addition of lead acetate it forms Lead acetate (black precipitate) which confirms the presence of sulfur. Hence option (A) is correct.
Which of the following compound is added to the sodium extract before?
(1) Nitric acid For testing of halogens, Nitric acid is added to the sodium extract because if CN– or S2– are present then they will be oxidised and removed before the test of halides.
Why is acetic acid necessary?
Hence, it is necessary to use acetic acid for acidification of sodium extract for testing sulphur by lead acetate test. In the estimation of sulphur by Carius method, 0.468 g of an organic sulphur compound afforded 0.668 g of barium sulphate.
What is the role of HNO3?
Nitric acid is a nitrogen oxoacid of formula HNO3 in which the nitrogen atom is bonded to a hydroxy group and by equivalent bonds to the remaining two oxygen atoms. It has a role as a protic solvent and a reagent. It is a conjugate acid of a nitrate.