Chemical Reactions and Stoichiometry Problems
I found myself completely lost for these five chem questions. I would really like very detailed answers for these, given the fact my teacher is out of town for the next week. I'd love to be able to see a step to step process for solving these, that way when I come across problems similar to this in the future and then, I don't get lost again.

1. 2Mn02 + 4KOH + O2 + CL2 ---> 2KMnO4 + 2KCL + 2H2O
For the reaction above, there is 100.0 g of each reactant available. Which reagent is the limiting reagent?

2. The reaction of 7.8 g of benzene (C6H6) with excess nitric acid resulted in 0.90 g of H2O. What is the percentage yield?
Molar mass (g/mol): C6H6=78, HNO3=63, C6H5NO2=123, H2O=18
C6H6 + HNO3 ----> C6H5NO2 + H2O

3. 6H+ + 5H2O + 2MnO4- ----> 5O2 + 2Mn2+ + 8H2O
According to the balanced equation above, how many moles of permanganate ion are required to react completely with 25.0 ml of .100 M hydrogen peroxide?

4. How many grams of water will be formed when 32.0 g of hydrogen is allowed to react with 16.0 g of oxygen according to the following reaction:
2H2 + O2 = 2H2O

5. What mass of Aluminum is produced when 0.5 mole of Al2S3 is completely reduced with excess H2?