Question

What mass, in grams, of fluorine gas (F2) is contained in a 10.3 liter tank at 29.8 degrees Celsius and 1.23 atmospheres? HELP PLEASE

Answer 1

You will be using: PV = nRT, the Ideal Gas Law, with a few unit conversions.

Does this sound familiar?

Answer 2

Looking for mass in grams, we'll first solve for number of moles and then convert.

Also, convert temperature units:
29.8 Celsius + 273.15 = 302.95 Kelvin

PV = nRT,
where P (Pressure) = 1.23 atmospheres
where V (Volume) = 10.3 liters
where n (moles) = ?
where R (Universal Gas Constant) = 0.08206 Latm/molK
where T (Temperature) = 29.8 Celsius + 273.15 = 302.95 Kelvin
(we need to convert into Kelvin otherwise the formula doesn't work)

n = PV/RT
n = (1.23 atm)(10.3 L) / (0.08206 Latm/molK)(302.95 K)
n = 0.50961 moles

m = (n)(mu)
where m = mass (in grams)
where n = number of moles
where mu = molar mass of F2 = 19 + 19 = 38 grams/mole

mass = (0.50961 moles)(38 grams/mole)
mass = 19.36527 ~ 19.3 grams