Decomposition
Complete and balance the following equations:
1.MgCO3 ---> +
2.HgO ---> +
3. PCl5 ---> +
4. (NH4)2Cr2O7 ---> + + N2
5. CuO ---> +

sorry bud. No one's going to sit here and do your homework for you. I mean... would you do 20+ problems for someone for poops and giggles?

We're more than glad to help you out if you have a question about some of them.

Here's a website to get you started on balancing equations

http://richardbowles.tripod.com/chemistry/balance.htm

You should know that

Metal carbonates decompose into their respective oxides, plus carbon dioxide
Metal oxides decompose into the metal itself and oxygen
And so on. Of course, there are exceptions that you should also keep in mind to minimise errors for exams.

Now, all that remains is balancing, and that, ISneezyFunny gave you a nice link for understanding that.

Hope it helped!