Question

A mixture of three noble gases has a total pressure of 1.25 atm. The individual pressures exerted by neon and argon are 0.68

atm and 0.35 atm, respectively. What is the partial pressure of the third gas, helium?
Use Py=P+P 2+P3+ +Pm

Answer 1

First of all, as you seen the gases are noble which means that will not react with each other and in this case each gas create individual pressure.

P
`_(T)`= total pressure

P
`_(Ne)` = pressure of neon

P
`_(Ar)` = pressure of argon

P
`_(He)` = pressure of helium {which is required}

P
`_(T)` = P
`_(Ne)` + P
`_(Ar)` + P
`_(He)`

1.25 = 0.68 + 0.35 + P
`_(He)`

P
`_(He)` = 1.25 - [0.68 + 0.35] = 0.22 atm