Chemistry quandaries?

Question

The folowing questions are questions I was given for a review for my final assessment in my Chemistry class. I wanted some help to make sure I was studying the correct answers and ways of answering these questions. Any helpful input is very much appreciated.
1. What is the difference between an oxidizing agent and a reducing agent?
2. When first learning to balance equations, we learned that the number of atoms of each element in the products and reactants must be equivalent. What are some additional factors that must be taken into account when balancing equations for redox reactions?
3. What are half reactions?
4. What two aspects of the half-reaction equations must be balanced?
5. For the equation Ag + NO3 -  Ag + + NO
This reaction takes place in an acidic solution.
What substance is reduced?
What substance is oxidized?
What is the half reaction for oxidation?
What is the half reaction for reduction?
What is the net balanced equation?
What is the reduced equation?

Answer 1

An oxidizing agent is the chemical which is reduced (gains electrons) in the reaction while a reducing agent is oxidized (loses electrons) in the reaction.

For balancing redox RXNs you must consider the oxidation states of each element. You must realize that the e- must also be balanced on both sides of the equation.

Half RXNs are considering just the oxidation or reduction part of the equation. Separate the oxidation and write and equation then write another equation using only the reduction.

Ag --> Ag 1+ + e- oxidation
7 e- + N 7- --> N 2- reduction