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Detection of Elements: Lassaigne's Test
1)When sodium nitroprusside is added to Lassagne’s extract, a violet colour is formed. It indicates the presence of ______________.
  
2)Which compound does not give a positive result in the Lassaigne’s test for nitrogen?
  
3)Which one of the following elements in an organic compound cannot be detected by Lassaigne’s test?
  
4)Which one of the following statements is not applicable to Lassaigne’s test?
  
5)In the Lassaigne’s test for the detection of nitrogen in an organic compound, the Prussian blue colour is due to the formation of _______________.
  
6)During the detection of sulphur in an organic compound, the violet colour formed by the addition of sodium nitroprusside to Lassaigne’s extract is due to _____________.
  
7)For the detection of sulphur in an organic compound, Lassaigne’s extract is acidified with acetic acid. Lead acetate solution is then added to it. The black precipitate formed is due to the formation of _______________.
  
8)Which of the following compounds is formed when an organic compound containing nitrogen is fused with sodium?
  
9)Which compound is formed when sodium is fused with an organic compound containing iodine?
  
10)A student added few drops of silver nitrate into Lassaigne’s extract of an organic compound containing bromine. Which one of the following is the correct observation?