A 5.15L balloon has a pressure of 1.35 atm. If compressed to 3.43L,
what will be the resulting pressure?

Solution:

Using Ideal Gas law:

 P1 = 1.45 atm

V1 = 5.15 L

P2 = ?

V2 = 3.43 L

Using Ideal Gas Law, PV = nRT:

Now, the number of moles (n) is the same independent of pressure and distance, so let's say that the temperature is stable since there is no details on the issue. As a consequence,

P1V1 = nRT = P2V2

P1V1 = P2V2

Solve for P2 and you're going to get 2.03 atm. It makes sense as you decrease the amount of the gas by compressing it, which implies that you raise the heat.

2) P = 1.5 atm

 T = 301 K

 n = 0.785 moles  

PV = nRT

 V = nRT/P

 R = 0.0821 (L*atm)/(mol * K)

 Therefore,  

 V = (0.785 * 0.0821 * 301)/1.5 = 19.4 L