Please help with this Chemistry assignment. Please show all work.

3 A solution contains 2.0x10-8 moles of H+ ion in 10.0 liters
A.What is the pH? B. What is the [OH-] C. What is the pOH ?
D. Is the solution acidic or basic ?
4. What is the pressure in atmospheres of 512g of N2 gas in an 12.00L
container at 37.0oC ?
5. Considering the auto airbag reaction:
2NaN3 ? 2Na + 3N2
How many liters of N2 gas result when 95.0 grams of NaN3 react
at 25.0oC and 0.95 atmosphere?
6..A. An isotope of atomic number 84 and a mass number of 212 emits an alpha
particle. What are the atomic number and mass number of the product?
B. An isotope of atomic number 48 and mass number 113 emits a beta particle.
What are the atomic number and mass number of the product?
7 Well A has a concentration of 0.011 ppm(parts per million) of Pb2+
Well B contains 6.5x10-4 grams of Pb2+ in 5.00 liters. Which well has the
smaller concentration of Pb2+ ? Show how you arrive at your answer.
8. If you initially have 275g of a radioactive isotope, how many grams remain
after 4 half lives?
9. A natural body of water has an O2 content of 8.00 milligrams per liter.
How many liters of it are required to decompose the organic matter in
1.00 liter of wastewater with a biological oxygen demand (BOD) of
137milligrams per liter. ?
10. Why is O3 (ozone) considered harmful on earth, but desirable in the
upper atmosphere? 

Additional Requirements 
Level of Detail: Show all work