JEE MainChemistryp Block Elements (Group 15, 16, 17 & 18)
Which of the following methods is specifically used to obtain very pure dinitrogen gas?
Options
- AThermal decomposition of ammonium dichromate
- BThermal decomposition of barium azide
- CTreating an aqueous solution of ammonium chloride with sodium nitrite
- DThermal decomposition of ammonium nitrate
Correct answer
B. Thermal decomposition of barium azide
Step-by-step solution
In the laboratory, dinitrogen is generally prepared by treating an aqueous solution of ammonium chloride with sodium nitrite, but the gas obtained contains small amounts of NO and HNO ₃ as impurities. Thermal decomposition of ammonium dichromate also yields dinitrogen, but it is not the preferred method for obtaining the gas in a highly pure state. Very pure dinitrogen is obtained by the thermal decomposition of sodium or barium azide. Ba(N ₃ ) ₂ Ba + 3 N ₂ Thermal decomposition of ammonium nitrate yields nitrous o