Test for Nitrogen

Put a piece of burning calcium into a jar of the unknown gas. If the calcium continues to burn, treat the product with water. If a pungent gas which turns moist red litmus paper to blue, the unknown gas would contain nitrogen.

This is because nitrogen reacts with burning calcium to give calcium nitride, which will react with water to give ammonia gas.
3Ca(s) + N2(g) → Ca3N2(s)
Ca3N2(s) + 6H2O(l) → 3Ca(OH)2(aq) + 6NH3(g)

The above reactions are out of HKCE and HKAL syllabus.

In glowing splint test, you know that oxygen gas will be relight it but goes out quickly, as the same test, carbon dioxide will go out at once. If the test at N2, because there is no oxygen, so as CO2 and go out.
In hydrogencarbonate indicator, oxygen will change to purple and carbon dioxide will change to yellow, but N2 will remain red.
In lime water test, oxygen will remain colourless and carbon dioxide will change it milky. At the same case, N2 will remain colourless.

另外有一個答案,請自上 :
http://hk.knowledge.yahoo.com/question/?qid=7006091702329