Question

two flasks are connected with a stopwingspan. flask #1 has a volume of 2.5L and contains oxygen gas at a pressure of .7atm. Flask #2 has a colume of 3.8L and contains hydrogen gas at a pressure of 1.25atm. when the stopwingspan between the two flasks is opened and the gases mix, what will the resulting pressure of the gas mixture be?

Answer 1

how you do this is add the 2 volumes
2.5+3.8=6.3
and call this V2

and then use the formula
P1V1=P2V2

for flask 1
P1 = .7atm
V1 = 2.5L
Pf1 = ?
V2 = .63L

rearranging the formula

Pf1= (.7)(2.5)/6.3 = ?

the same for
flask2
P1 = 1.25atm
V1 = 3.8L
Pf2 = ?
V2 = 6.3L

Pf2=(1.25)(3.8)/6.3

lastly

Pf1 + Pf2 = Ptot

Ptot -= ?

Answer 2

I feel like this is more of a math question but at the same time im not sure. @zpupster explained this well.