What will be the partial pressure of gas in the mixure if the temp is constant

Question

a 2.0L container,full of helium at 2.5atm pressure is connected to a 3.0L container full of oxygen at 3.0atm pressure. the gases are aloud to mix freely what will be the partial pressure of gas in the mixture if the temp is constant?

Answer 1

For helium p v = p' v'  or  2 L x 2.5 atm = p' (2+3)L.

p' = 1 atm.