Identify the reactions in which N₂ is liberated 

a) ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{SO}}_4 + \mathrm{NaOH}\to$

b) ${\mathrm{NH}}_3\left(\mathrm{excess}\right)+{\mathrm{Cl}}_2 \to$

c) ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{Cr}}_2{\mathrm{O}}_7\stackrel{∆}{\to }$

d) ${\mathrm{NH}}_4{\mathrm{NO}}_3\stackrel{∆}{\to }$

e) ${\mathrm{NH}}_4{\mathrm{Cl}}_{\left(\mathrm{aq}\right)} + {\mathrm{NaNO}}_{2\left(\mathrm{aq}\right)}\to$

(NH₄)₂SO₄+2NaOH→ Na₂SO₄+2H₂O+2NH₃.

3Cl_2​+8NH₃​(excess)→6NH_4​Cl+N_2​

(NH₄​)₂​Cr₂​O₇​→N_2​+Cr₂​O_3​+4H₂​O

NH₄​NO₃​(s)⟶N_2​O(g)+2H₂​O(l)

NH₄​Cl(aq)+NaNO₂​(aq)→N_2​(g)+2H₂​O(l)+NaCl(aq)