The total pressure in the container is <u>2.02</u> atm.
<em>Step</em> 1. Calculate the<em> total number of moles.
</em>
Moles of He = 1.00 g He × (1.00 mol He/4.003 g He) = 0.2498 mol He
Moles of F₂ = 14.0 g F₂ × (1 mol F₂/38.00 g F₂) = 0.3684 mol F₂
Moles of Ar = 19.00 g Ar × (1 mol Ar/39.95 g Ar) = 0.4756 mol Ar
<em>Total moles</em> = (0.2498 + 0.3684 + 0.4756) mol = <em>1.094 mol
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<em>Step </em>2. Calculate the <em>total pressure</em>.
Use the <em>Ideal Gas Law</em>: <em>pV = nRT
</em>
We can solve the equation to get the pressure:
<em>p</em> = (<em>nRT</em>)/<em>V</em>
<em>n</em> = 1.094 mol
<em>R</em> = 0.082 06 L·atm·K⁻¹mol⁻¹
<em>T</em> = (20.0 + 273.15) K = 293.15 K
<em>V</em> = 13.0 L
∴ <em>p</em> = (1.094 mol × 0.082 06 L·atm·K⁻¹mol⁻¹ × 293.15 K)/13.0 L = 2.02 atm