The compound in question is called Ammonium Perchlorate, and is abbreviated AP in the pyrotechnics/amateur rocket field. It is a powerful oxidizer and is used in the solid rocket fuel boosters that the space shuttle uses to drive into space. It is mixed with powdered Al as fuel, and a tad of iron oxide as a catalyst (think 'suped-up' thermite). A large amount of this fuel was stored in a Nevada desert site, and was the cause of a massive explosion. You can look it up online if you're interested.
The best ways to tell how powerful an oxidizer an ion is are:
- Look at an electromotive series in the back of a chem book; ions that are strongly reducing are on one end of the table (along with sodium metal, etc.), and the strongly oxidizing ones are on the other end (along with fluorine gas, etc.).
- In the back of most inorganic chem textbooks are charts that depict the reduction potentials for different oxidation states of elements. The larger the potential, the more reactive and depending on the sign, is either a hot reduction agent or oxidizing agent.
- You can also add up the oxidation states on the periodic table for polyatomic ions and find out what the oxidation state of a particular atom is. For example, in Cl2, chlorine has a 0 oxidation state, but in ClO4-, it has an oxidation state of +7. That basically means it wants electrons badly; since it will take electrons away from another atom, the other atom will be oxidized.
Some common oxidizing agents are:
- bleach (NaOCl)
- perchlorates (ClO4-)
- chlorates (ClO3-)
- nitrates (NO3-)
This is just the tip of the iceberg, and I'm sure you'll get more detailed posts and more information from others.