61.24 is the molar mass of a gas which has a density of 0.00249 g/mL at 20.0 degrees celcius and 744.0 mm Hg.
Explanation:
given that:
density = 0.00249 g/ml ([tex]\frac{mass}{volume}[/tex]) or 2.49 grams/litre
P = 744 mm Hg OR 0.978 atm
T = 20 Degrees or 293.15 Kelvin
R = 0.08206 Litre atm/mole K
molar mass =?
Formula used/
PV = nRT equation 1
here n is number of moles:
n = [tex]\frac{mass}{atomic mass}[/tex]
putting the value of n and value of density in the equation 1:
PV = [tex]\frac{mass}{molar mass}[/tex] x RT
molar mass = [tex]\frac{mass}{volume}[/tex] x [tex]\frac{RT}{P}[/tex]
= density x [tex]\frac{RT}{P}[/tex]
= [tex]\frac{2.49 x 0.08276 x 293.15}{0.978}[/tex]
= 61.24 is the molar mass of the gas.
