Question

4) A sealed glass container contains 1.61 moles of He gas and 2.64 moles of Ar gas. If the total pressure inside the container is 0.872 atm what is the partial pressure of He in the glass container? Keep answer with 3 decimal places

Answer 1

`P_(He)=0.330\text{ }atm`

Procedure

The total pressure of a mixture of gases can be defined as the sum of the pressures of each individual gas:

`P_(total)=P_1+P_2+...+P_n`

The partial pressure of an individual gas is equal to the total pressure multiplied by the mole fraction of that gas.

`P_i=P_(total)x_i`

The molar fraction of He is determined by dividng the moles of He over the total moles

`x_(He)=(1.61)/((1.61+2.64))=0.3788`

Finally, the total pressure of He is

`P_(He)=0.872\text{ atm}(0.3788)=0.330\text{ }atm`