What pressure will be exerted by 109 grams of fluorine gas in a 3,4000mL cylinder at 20degree celcius?

Convert 109g F2 to moles.

Convert 3,4000mL(?) to liters.
Convert 20ºC to degrees Kelvin
R = 0.0821 L.atm/ºK.mol
Substitute into PV = nRT
Solve for P