Oxidation Reduction Reactions HELP!

Question

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

(Note: This reaction takes place in an acidic solution.)

Step 1: What substance is reduced?

Step 2: What substance is oxidized?

Step 3: What is the half reaction for oxidation?

Step 4: What is the half reaction for reduction?

Step 5: What is the net balanced equation?

Step 6: What is the reduced equation?

Answer 1

1. Oxidizing agent oxidizes an atom, while reducing agent reduces the atom. This is defined by oxidation number. I'm not sure if you know all this but Alkali Metals are 1+, Alkaline Earth Metals are 2+, Oxygen group is 2-, Halogens is 1-, Carbon group generally 4+ or 4-, etc.

O2 + Mg2 <--> 2MgO

Here the numbers are easy: natural and pure elements have an oxidation number of 0. So O2 and Mg2 have charges of 0. However, in Magnesium Oxide, because of the placement in the periodic table, Mg now has an oxidation number of 2+, and O has 2-.

To oxidize something is to raise the oxidation number. To reduce is to...reduce that number.

So Oxygen was reduced, and Magnesium was raised/oxidized. And therefore O is the oxidizing agent, and Mg is the reducing agent.

2. True. You also have to take into account charges to make sure that nothing's funny. In the previous equation O2 + Mg2 <--> 2MgO, you need to make sure that MgO does not have a weird charge. Just make sure everything's neutral, unless otherwise noted.

3. Half Reactions deal with electrons coming off or on, usually with products involving e-

Again: O2 + Mg2 --> 2MgO

Half Reactions using the oxidation numbers

O2 + 2e- --> 2O-

Mg2 --> 2Mg + 2e-

4. -----

A. No missing or added material

B. Correct oxidation numbers and charges on molecules

5. I'm not sure what your equation says because there's a weird symbol floating around. But I guess I could take a stab. But it might be hard. The number of reactants doesn't match up with the number of products.

1. O3 = -2 x 3 = -6

N = -3

Since the molecule is neutral, the charge of Ag (let's say x) and the rest must equal 0

x + -3 + -6 = 0

x = 9 (wow that's big. seems weird)

But in AgNO,

O = -2 x 1 = -2

N = -3

x + -3 + -2 = 0

x = 5

So Ag went from 9 --> 5, meaning that it was reduced.

And that's about all I can help you with since I can't find your true reaction.

Hope this helps.

Enjoy.