The pressure exerted by a gas can be calculated using the ideal gas law, which states that PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the gas constant, and T is the temperature in kelvins.
Plugging in the given values, we get:
P = (nRT) / V
P = (1.35 mol * 8.31 J/mol*K * 320.0 K) / (2.50 L * 10^-3 m^3)
P = (4460.8 J) / (0.0025 m^3)
P = 17843.2 Pa
To convert from pascals to atmospheres, we divide by 101325 Pa/atm:
P = 17843.2 Pa / 101325 Pa/atm
P = 0.176 atm
So, the pressure exerted by 2.50 L of HF containing 1.35 mol at 320.0 K is approximately 0.176 atm.