Chemistry Help with Stoichiometry + Measurement of Gases?

[yerdamonkeysofdoom]

My chemistry teacher did a horrible job teaching the lesson of Stoichiometry and Measurement of Gases. I would be grateful if someone could post a very helpful explanation of how to solve these two sample problems. Thanks very much in advance.

() means subscript

Ammonia, NH(3), is the most important commercial compound of nitrogen. It can be produced by reacting nitrogen with hydrogen gas. This is the process used to produce ammonia commercially and is known as the Haber process.

The equation given is:

N(2)(g) + 3H(2)(g) ----> 2NH(3)(g)

1. Ammonia is kept at 15 degrees Celsius in a 10.0-L flask with a pressure of 1.95 atm. What is the pressure in the flask if the temperature is increased to 25 degrees Celsius?
2. Ammonia is kept in a cylinder with a movable piston at 25 degrees Celsius and 2.50 atm pressure. What is the pressure in the cylinder if the temperature is increased to 45 degrees Celsius and the piston is raised so that the volume occupied by the gas is doubled?

THANKS!