A Helium filled balloon has volume of 1.0 L at 23 degrees Celsius and is at 1.18 bar. It is released into the air at which point the pressure becomes 220 Torr. Calculate the change in volume that occurs.
A Helium filled balloon has volume of 1.0 L at 23 degrees Celsius and is at 1.18 bar. It is released into the air at which point the pressure becomes 220 Torr. Calculate the change in volume that occurs.
PV=nRT
Calculate the amount of moles (n) initially (the only value you don't have from the equation). This value will stay the same for the final phase. Pressure becomes 220 Torr and I'm assuming P and T are at STP for the final phase. Use the PV=nRT formula again with the new variables to calculate V. Obviously R is constant.
I'm assuming since you are asking this question you are in basic Chemistry, so PV=nRT should be the equation for you to use and not a modification of it. Also, make sure you notice the change of units from bars (initially) to Torr (final stage).
As always in Chemistry, there are various methods to solving an equation. This one should be easiest for you.
Yea I did this and ended up getting 4.04. So the change is 4.04 - 1 = 3.04 L?
I just wanted to confirm with someone I did it right. I thought that T is 23 + 273 like it was initially.
That answer sounds reasonable. I got 3.01L, but I wasn't keeping track of sig figs. I guess since it is in a balloon it would be at the same temperature, you're right. I tend to over-think things sometimes.
Also, like I was saying before, you could have solved it differently. Moles, R, and T all stay constant. So you could have just simply solved it as P1V1=P2V2, no moles even involved.