I cant quite figure out these chemistry problems

Question

Consider the following reaction.  

Zn + NO3- → Zn2+ + NH3

(a) Identify the oxidation number of each atom in the reaction above. Based on the oxidation numbers, explain how you know this is a redox reaction.

(b) Separate the reaction into the two half-reactions that occur. Identify each half-reaction as oxidation or reduction.  

(c) Write the balanced equation for this reaction if it occurs in basic solution.

(d) Identify the reducing agent and the oxidizing agent in the reaction.

Answer 1

Zn + NO₃^- ==> Zn²⁺ + NH₃

a) Zn goes from oxidation number of zero on the left to 2+ on the right. It has lost electrons

N in NO₃^- goes from oxidation number of 5+ on the left to 3- on the right. It has gained electrons

Because one substance loses electrons and another gains electrons, this is a redox reaction.

b) Zn ==> Zn²⁺ + 2e- This is the oxidation half reaction

NO₃^- + 8e- ==> NH₃ This is the reduction half reaction

c)Zn ==> Zn²⁺ + 2e- This is the oxidation half reaction

NO₃^- + 6H2O + 8e- ==> NH₃ + 9OH^- This is the reduction half reaction in basic conditions

Multiply oxidation reaction by 4 to equalize the electrons and add the two half reactions to get...

4Zn + NO₃^- + 6H₂O ==> 4Zn⁺² + NH₃ + 9OH^- ... balanced equation (without combination)

d) The reducing agent is Zn and the oxidizing agent is NO₃^-