Question #777e2

1 Answer
May 12, 2016

Answer:

The pressure is unknown. The partial pressure is a multiple of the mole fraction of each component.

Explanation:

We have volume, and amount of substance; we do not have temperature, which we require if pressure is to be calculated. I assume that the temperature is #298*K#.

#"Moles of helium:"# #(32.6*g)/(4.0*g*mol^-1)=8*mol#

#"Moles of dioxygen:"# #(51.2*g)/(32.0*g*mol^-1)=1.6*mol#

The total pressure #P=(nRT)/V# #=#

#((8.0+1.6)*molxx0.0821*L*atm*K^-1*mol^-1xx298*K)/(0.150*L)# #=# #P_T#

The partial pressure of dioxygen #P_(O_2)=(P_(O_2))/P_T# #=# #(1.6*mol)/((8+1.6)*mol)xxP_T#.

This sounds like a deep sea diving mix, where helium replaces dinitrogen in order to avoid the narcotic effect of dinitrogen.