The total pressure in the container is 2.02 atm.
Step 1. Calculate the total number of moles.
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
Total moles = (0.2498 + 0.3684 + 0.4756) mol = 1.094 mol
Step 2. Calculate the total pressure.
Use the Ideal Gas Law: pV = nRT
We can solve the equation to get the pressure:
p = (nRT)/V
n = 1.094 mol
R = 0.082 06 L·atm·K⁻¹mol⁻¹
T = (20.0 + 273.15) K = 293.15 K
V = 13.0 L
∴ p = (1.094 mol × 0.082 06 L·atm·K⁻¹mol⁻¹ × 293.15 K)/13.0 L = 2.02 atm
