Combined+Law+R.+Stacey

D. Combined Gas Law: The combined gas law expresses the relationship between pressure, volume and temperature of a fixed amoutn of gas. Equation :

Sample Problem: A helium-filled balloon has a volume of 50.0 L at 25 C and 1.08 atm. What volume will it have at .855 atm and 10.0 C?   Given: V1 of He = 50.0 L   P1 of He = 1.08 atm T1 of He = 25 C = 273 K = 298 K  T2 of He = 10 C = 273 = 283 K   Unknown: V2 of he in L    So we have to re-arrange the equation again, to isolate V2: __ T2 P1V1 __ = __P2____V2 x 1 x T2__ P2 T1 T2  P2     Now this is WAY too messy! So, when we clean it up, it looks like this: V2 = __P1V1T2__ P2T1 then, plug the values in: V2 = __(1.08 atm) (50.0l He) (283 K)__ = 60.0 L He (0.855 atm) (298 K)  main page.........