posted by kellie on .
Determine the density of methane (CH4) in g/L at 24.7oC and 1.1 atm
ideal gas eqn: P = (rho)RT, where:
pressure: P = 1.1 atm
specific gas constant: R, R = |R / M, where
|R = 0.0821 L-atm / K-mol and,
molecular weightCH4: M = 0.016 kg/mol
R = 0.0821/0.016 = 5.13 and
temp. T = 24.7 + 273 = 291 K, therefore,
density: (rho) = P / RT = 1.1 / (5.13)(291)
(rho) = 62.4 g/L
please tell me if this is correct if not help me to correct my work
No, it isn't correct. First, since you know T to the tenth, I would use 273.2 + 27.4 for T and that gives 297.9 K and not 291 K. Then if I wanted density in g/L I would use the molar mass in grams.
PM = rho*RT and
rho = PM/RT = (1.1*16)/(0.0821*297.9) = 0.7196 g/L which I would round to 0.720 g/L.