Answer
Verified
370.8k+ views
Hint: Lassaigne’s test is used to determine the foreign elements in the presence of organic compounds like carbon and nitrogen. These foreign elements are nitrogen, sulfur and halogen.
Complete answer:
Lassaigne’s test is also known as sodium fusion test. The halogen, Nitrogen and Sulfur are covalently bonded to the organic compound and in order to detect them the element first need to converted into ionic form and this is extracted in the aqueous solution and further easily be detected by simple chemical test and the extract is called sodium fusion extract or Lassaigne’s extract. In this reaction first sodium fuses with carbon and nitrogen and forms sodium cyanide and further it reacts with sulphur to form sodium thiocyanate.
The reaction is-
\[{\text{Na + C + N + S }}\xrightarrow{{fuse}}{\text{NaSCN }}\left( {{\text{Sodium Thiocyanate}}} \right)\]
\[{\text{NaCN}}\] and \[{\text{N}}{{\text{a}}_2}{\text{S}}\] is not possible because only one product will be formed by fusion , first \[{\text{Na}}\] reacts with \[{\text{N}}\] and \[{\text{C}}\] to form \[{\text{NaCN}}\] and then it again fuses with the Sulfur to form \[{\text{NaSCN}}\] . In the same way other two products like\[{\text{NaN}}{{\text{H}}_2}\], \[{\text{N}}{{\text{a}}_2}{\text{S}}{{\text{O}}_4}\], \[{\text{NaN}}{{\text{O}}_3}\] and \[{\text{N}}{{\text{a}}_2}{\text{S}}\]are not possible. Therefore, the correct answer is \[{\text{NaSCN}}\]
Hence the correct answer is option ‘C’.
Note:In Lassaigne’s test for nitrogen, Prussian blue colour is obtained due to formation of ferriferous cyanide complex. Violet colour indicates presence of sulphur. White precipitate indicates the presence of chlorine.
Complete answer:
Lassaigne’s test is also known as sodium fusion test. The halogen, Nitrogen and Sulfur are covalently bonded to the organic compound and in order to detect them the element first need to converted into ionic form and this is extracted in the aqueous solution and further easily be detected by simple chemical test and the extract is called sodium fusion extract or Lassaigne’s extract. In this reaction first sodium fuses with carbon and nitrogen and forms sodium cyanide and further it reacts with sulphur to form sodium thiocyanate.
The reaction is-
\[{\text{Na + C + N + S }}\xrightarrow{{fuse}}{\text{NaSCN }}\left( {{\text{Sodium Thiocyanate}}} \right)\]
\[{\text{NaCN}}\] and \[{\text{N}}{{\text{a}}_2}{\text{S}}\] is not possible because only one product will be formed by fusion , first \[{\text{Na}}\] reacts with \[{\text{N}}\] and \[{\text{C}}\] to form \[{\text{NaCN}}\] and then it again fuses with the Sulfur to form \[{\text{NaSCN}}\] . In the same way other two products like\[{\text{NaN}}{{\text{H}}_2}\], \[{\text{N}}{{\text{a}}_2}{\text{S}}{{\text{O}}_4}\], \[{\text{NaN}}{{\text{O}}_3}\] and \[{\text{N}}{{\text{a}}_2}{\text{S}}\]are not possible. Therefore, the correct answer is \[{\text{NaSCN}}\]
Hence the correct answer is option ‘C’.
Note:In Lassaigne’s test for nitrogen, Prussian blue colour is obtained due to formation of ferriferous cyanide complex. Violet colour indicates presence of sulphur. White precipitate indicates the presence of chlorine.
Recently Updated Pages
Basicity of sulphurous acid and sulphuric acid are
Three beakers labelled as A B and C each containing 25 mL of water were taken A small amount of NaOH anhydrous CuSO4 and NaCl were added to the beakers A B and C respectively It was observed that there was an increase in the temperature of the solutions contained in beakers A and B whereas in case of beaker C the temperature of the solution falls Which one of the following statements isarecorrect i In beakers A and B exothermic process has occurred ii In beakers A and B endothermic process has occurred iii In beaker C exothermic process has occurred iv In beaker C endothermic process has occurred
What is the stopping potential when the metal with class 12 physics JEE_Main
The momentum of a photon is 2 times 10 16gm cmsec Its class 12 physics JEE_Main
How do you arrange NH4 + BF3 H2O C2H2 in increasing class 11 chemistry CBSE
Is H mCT and q mCT the same thing If so which is more class 11 chemistry CBSE
Trending doubts
Difference Between Plant Cell and Animal Cell
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
Change the following sentences into negative and interrogative class 10 english CBSE
Summary of the poem Where the Mind is Without Fear class 8 english CBSE
Give 10 examples for herbs , shrubs , climbers , creepers
Write an application to the principal requesting five class 10 english CBSE
What organs are located on the left side of your body class 11 biology CBSE
What is the z value for a 90 95 and 99 percent confidence class 11 maths CBSE