CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317499
Assertion : During the test for nitrogen with Lassaigne extract, on adding \(\mathrm{FeCl}_{3}\) solution sometimes a red precipitate is obtained. Reason : Sulphur is also present.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
During test for nitrogen with Lassaigne extract, on adding \(\mathrm{FeCl}_{3}\) solution a red precipitate is obtained when both nitrogen and sulphur are present. \(\begin{gathered}\mathrm{Na}+\underbrace{\mathrm{C}+\mathrm{N}+\mathrm{S}}_{\begin{array}{c}\text { from organic } \\\text { compound }\end{array}} \rightarrow \mathrm{NaCNS} \\3 \mathrm{NaCNS}+\mathrm{FeCl}_{3} \rightarrow \mathrm{Fe}(\mathrm{CNS})_{3}+3 \mathrm{NaCl} \\\text { blood red colouration }\end{gathered}\)
AIIMS - 2007
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317500
In which of the following compounds, presence of nitrogen cannot be detected by Lassaigne's method?
1 Hydrazine
2 Aniline
3 p-toluidine
4 Picric acid
Explanation:
\(\mathrm{N}_{2} \mathrm{H}_{4}\) has no carbon. So, it can't form \(\mathrm{NaCN}\) in Lassaigne's test.
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317501
0.1 g of an organic comound containing phosphorus gave 0.20 g of \({\rm{M}}{{\rm{g}}_{\rm{2}}}{{\rm{P}}_{\rm{2}}}{{\rm{O}}_{\rm{7}}}\) by the usual analysis. Percentage of phosphorus in the compound is ____.
1 92
2 46
3 54
4 66
Explanation:
Percentage of phosphorus \(\begin{aligned}& =\dfrac{62}{222} \times \dfrac{\text { Mass of } \mathrm{Mg}_{2} \mathrm{P}_{2} \mathrm{O}_{7}}{\text { Mass of compound }} \times 100 \\& \dfrac{62}{222} \times \dfrac{0.20}{0.1} \times 100=54 \%\end{aligned}\)
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317502
The formula of the compound which gives violet colour in Lassaigne's test for sulphur with sodium nitroprusside is
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317499
Assertion : During the test for nitrogen with Lassaigne extract, on adding \(\mathrm{FeCl}_{3}\) solution sometimes a red precipitate is obtained. Reason : Sulphur is also present.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
During test for nitrogen with Lassaigne extract, on adding \(\mathrm{FeCl}_{3}\) solution a red precipitate is obtained when both nitrogen and sulphur are present. \(\begin{gathered}\mathrm{Na}+\underbrace{\mathrm{C}+\mathrm{N}+\mathrm{S}}_{\begin{array}{c}\text { from organic } \\\text { compound }\end{array}} \rightarrow \mathrm{NaCNS} \\3 \mathrm{NaCNS}+\mathrm{FeCl}_{3} \rightarrow \mathrm{Fe}(\mathrm{CNS})_{3}+3 \mathrm{NaCl} \\\text { blood red colouration }\end{gathered}\)
AIIMS - 2007
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317500
In which of the following compounds, presence of nitrogen cannot be detected by Lassaigne's method?
1 Hydrazine
2 Aniline
3 p-toluidine
4 Picric acid
Explanation:
\(\mathrm{N}_{2} \mathrm{H}_{4}\) has no carbon. So, it can't form \(\mathrm{NaCN}\) in Lassaigne's test.
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317501
0.1 g of an organic comound containing phosphorus gave 0.20 g of \({\rm{M}}{{\rm{g}}_{\rm{2}}}{{\rm{P}}_{\rm{2}}}{{\rm{O}}_{\rm{7}}}\) by the usual analysis. Percentage of phosphorus in the compound is ____.
1 92
2 46
3 54
4 66
Explanation:
Percentage of phosphorus \(\begin{aligned}& =\dfrac{62}{222} \times \dfrac{\text { Mass of } \mathrm{Mg}_{2} \mathrm{P}_{2} \mathrm{O}_{7}}{\text { Mass of compound }} \times 100 \\& \dfrac{62}{222} \times \dfrac{0.20}{0.1} \times 100=54 \%\end{aligned}\)
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317502
The formula of the compound which gives violet colour in Lassaigne's test for sulphur with sodium nitroprusside is
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317499
Assertion : During the test for nitrogen with Lassaigne extract, on adding \(\mathrm{FeCl}_{3}\) solution sometimes a red precipitate is obtained. Reason : Sulphur is also present.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
During test for nitrogen with Lassaigne extract, on adding \(\mathrm{FeCl}_{3}\) solution a red precipitate is obtained when both nitrogen and sulphur are present. \(\begin{gathered}\mathrm{Na}+\underbrace{\mathrm{C}+\mathrm{N}+\mathrm{S}}_{\begin{array}{c}\text { from organic } \\\text { compound }\end{array}} \rightarrow \mathrm{NaCNS} \\3 \mathrm{NaCNS}+\mathrm{FeCl}_{3} \rightarrow \mathrm{Fe}(\mathrm{CNS})_{3}+3 \mathrm{NaCl} \\\text { blood red colouration }\end{gathered}\)
AIIMS - 2007
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317500
In which of the following compounds, presence of nitrogen cannot be detected by Lassaigne's method?
1 Hydrazine
2 Aniline
3 p-toluidine
4 Picric acid
Explanation:
\(\mathrm{N}_{2} \mathrm{H}_{4}\) has no carbon. So, it can't form \(\mathrm{NaCN}\) in Lassaigne's test.
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317501
0.1 g of an organic comound containing phosphorus gave 0.20 g of \({\rm{M}}{{\rm{g}}_{\rm{2}}}{{\rm{P}}_{\rm{2}}}{{\rm{O}}_{\rm{7}}}\) by the usual analysis. Percentage of phosphorus in the compound is ____.
1 92
2 46
3 54
4 66
Explanation:
Percentage of phosphorus \(\begin{aligned}& =\dfrac{62}{222} \times \dfrac{\text { Mass of } \mathrm{Mg}_{2} \mathrm{P}_{2} \mathrm{O}_{7}}{\text { Mass of compound }} \times 100 \\& \dfrac{62}{222} \times \dfrac{0.20}{0.1} \times 100=54 \%\end{aligned}\)
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317502
The formula of the compound which gives violet colour in Lassaigne's test for sulphur with sodium nitroprusside is
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317499
Assertion : During the test for nitrogen with Lassaigne extract, on adding \(\mathrm{FeCl}_{3}\) solution sometimes a red precipitate is obtained. Reason : Sulphur is also present.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
During test for nitrogen with Lassaigne extract, on adding \(\mathrm{FeCl}_{3}\) solution a red precipitate is obtained when both nitrogen and sulphur are present. \(\begin{gathered}\mathrm{Na}+\underbrace{\mathrm{C}+\mathrm{N}+\mathrm{S}}_{\begin{array}{c}\text { from organic } \\\text { compound }\end{array}} \rightarrow \mathrm{NaCNS} \\3 \mathrm{NaCNS}+\mathrm{FeCl}_{3} \rightarrow \mathrm{Fe}(\mathrm{CNS})_{3}+3 \mathrm{NaCl} \\\text { blood red colouration }\end{gathered}\)
AIIMS - 2007
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317500
In which of the following compounds, presence of nitrogen cannot be detected by Lassaigne's method?
1 Hydrazine
2 Aniline
3 p-toluidine
4 Picric acid
Explanation:
\(\mathrm{N}_{2} \mathrm{H}_{4}\) has no carbon. So, it can't form \(\mathrm{NaCN}\) in Lassaigne's test.
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317501
0.1 g of an organic comound containing phosphorus gave 0.20 g of \({\rm{M}}{{\rm{g}}_{\rm{2}}}{{\rm{P}}_{\rm{2}}}{{\rm{O}}_{\rm{7}}}\) by the usual analysis. Percentage of phosphorus in the compound is ____.
1 92
2 46
3 54
4 66
Explanation:
Percentage of phosphorus \(\begin{aligned}& =\dfrac{62}{222} \times \dfrac{\text { Mass of } \mathrm{Mg}_{2} \mathrm{P}_{2} \mathrm{O}_{7}}{\text { Mass of compound }} \times 100 \\& \dfrac{62}{222} \times \dfrac{0.20}{0.1} \times 100=54 \%\end{aligned}\)
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317502
The formula of the compound which gives violet colour in Lassaigne's test for sulphur with sodium nitroprusside is
