3Mg N2 Mg3N2 oxidation half reaction Mg Mg2 e reducti

3Mg + N2 --> Mg3N2

oxidation half reaction

(?) Mg --> (?) Mg2 + (?) e-

reduction half reaction

(?) N2 + (?) e- --> (?)N3-

What is the oxidizing agent?

a.     Mg

b.     Mg2+    

c.     N3-

d.     N2

What is the reducing agent?

a.     Mg

b.     Mg2+    

c.     N2

d.     N3-

Solution

Oxidation half reaction :

3Mg - - - - -> 3Mg2+ + 6 e-

Reduction half reaction :

N2 + 6e- - - - - - > 2N3-

Oxidizing agent are those which make other oxidized and itself got reduced, so, N2 here is the oxidizing agent.

Reducing agents are those which make others reduced but itslelf got oxidized, so, here Mg is the reducing agent.