Answer:
[tex]P_{He}=9.06torr[/tex]
Explanation:
Hello there!
In this case, we can identify the solution to this problem via the Dalton's rule because the partial pressure of helium is given by:
[tex]P_{He}=x_{He}P_T[/tex]
Whereas the mole fraction of helium is calculated by firstly obtaining the moles and then the mole fraction:
[tex]n_{He}=8.00g\frac{1mol}{4.00g}=2.00mol\\\\ x_{He}=\frac{n_{He}}{n_{He}+n_{Ar}} \\\\ x_{He}=\frac{2.00mol}{2.00mol+8.60mol}\\\\x_{He}=0.189[/tex]
Then, we calculate the partial pressure as shown below:
[tex]P_{He}=0.189 *48.0torr\\\\P_{He}=9.06torr[/tex]
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