Well, that’s the problem. I mean with you’re balloon analogy. My mind knows instinctively what happens to the balloon. It will lose volume. But, according to Boyle’s law, the pressure in the balloon will increase, because P and V are inversely proportionate.

I found the answer to the problem, but I found it through trial and error. I will state the problem, and give my answer. My answer was derived by the fact that I knew that as the pressure decreased by a value of four, then the volume must increase by four. This turned out not to be exactly true. I figured this as an inverse property. And then there’s the temp thing. Gay-Lussacs law says as the temp increases, the pressure increases, which makes sense. But that’s not what happens in this particular question. So, I will quote the question verbatim from the text and give my answer.

A 25.0 ml bubble is released from a divers air tank at a pressure of 4.00 atm and a temp of 11*C. What is the volume (ml) of the buble when it reaches the ocean surface, where the pressure is 1.00 atm and the temp is 18*C?

So, I took the change in P1 & P2 as a value of 4, and knew that V2 was close to 100 ml.

Actually I thought it was 100 ml. But, when I ran it through the original equation (combined gas law) the numbers were close, but not the same.

My answer for V2 was 102.464789. In other words 102. But that took quite a bit of calc work to derive; I guess maybee because my algebra is a little rusty. I’m actually better in the back of the textbook than I am here, and was gonna skip this stuff, but I know it’s gonna come up at the university, if I ever make it there.

Sorry for the long post, but you’re response made me open my eyes. I’ve realized that I’m gonna have to learn up to Calculus 3 for the degree I want, but I don’t see that happening on my own. I’m trying to teach myself everything I can on my own, and thought I was doing good until now

I still don’t understand how to manipulate the equation to come up with the second equation. Like I said, I found the answer through trial & error. Maybe I need to dig my algebra tombs out and dust them off a little. I know this is basic stuff here.