Activity Card, Part 2

Now for some serious PROBLEM SOLVING.

  The Activity Card is divided into two parts, the first one is an experiment and the other is pure solving.

Now, to prove what you have learned over the past lessons. Kindly answer the following questions, and see how you have learned so far! 

Questions:
1. A balloon contains 0.1 moles of oxygen and 0.4 moles of nitrogen. If the balloon is at standard temperature and pressure, what is the partial pressure of the nitrogen?

2. A gas in a cylinder occupies a volume of 0.065 m3 at room temperature (T = 293 K). The gas is confined by a piston with a weight of 100 N and an area of 0.65 m2. The pressure above the piston is atmospheric pressure.
(a) What is the pressure of the gas? 

(b) The gas is heated, expanding it and moving the piston up. If the volume occupied by the gas doubles, how much work has the gas done?
(c) What is the final temperature of the gas?

Source: http://www.pharmacology2000.com/physics/Chemistry_Physics/gas_law_problems1.htm               http://water.me.vccs.edu/pressure2.htm