How is nitrogen prepared in the laboratory ?
Write the chemical equations of the reactions involved.

Explanation

Preparation of di Nitrogen :
`to` Very pure nitrogen is obtained by the thermal decomposition of sodium (or) barium a-zide.
`"Ba"(N_(3))_(2)to"Ba"+3N_(2)`
`to` In the laboratory dinitrogen is prepared by treating an aqueous solution of `"NH"_(4)Cl` with `"NaNO"_(2)`
`"NH"_(4)Cl_(("aq"))+"NaNO"_(2("aq"))toN_(2_((g)))+2H_(2)O_((1))+"NaCl"_(("aq"))`
`to` Nitrogen can also be obtained by the thermal decomposition of ammonium dichromate.
`(NH_(4))_(3)"Cr"_(2)O_(7)overset(Delta)toN_(2)+4H_(2)O+"Cr"_(2)O_(3)`