Answer:
138.57 g/mol.
Explanation:
The following data were obtained from the question:
Temperature (T) = 23.8 °C
Pressure = 432 mmHg
Density (D) = 3.23 g/L
Next, we shall obtain an expression for the density in relation to molar mass, pressure and temperature.
This can be obtained by using the ideal gas equation as shown below:
PV = nRT.... (1)
Recall:
Mole (n) = maas(m) /Molar mass (M)
n = m/M
Substituting the value of n into equation 1
PV = nRT
PV = mRT/M
Divide both side by P
V = mRT/MP
Divide both side by m
V/m = RT/MP
Invert the above equation
m/V = MP /RT..... (2)
Recall:
Density (D) = mass(m) /volume (V)
D = m/V
Replace m/V with D in equation 2
m/V = MP /RT
D = MP /RT
Thus, with the above formula we can obtain the molar mass of chlorofluorocarbon (CFC) as shown below:
Temperature (T) = 23.8 °C = 23.8 °C + 273 = 296.8 K
Pressure = 432 mmHg = 432/760 = 0.568 atm
Density (D) = 3.23 g/L
Gas constant (R) = 0.0821 atm.L/Kmol
Molar mass (M) =..?
D = MP /RT
3.23 = M x 0.568 / 0.0821 x 296.8
Cross multiply
M x 0.568 = 3.23 x 0.0821 x 296.8
Divide both side by 0.568
M = (3.23 x 0.0821 x 296.8) / 0.568
M = 138.57 g/mol
Therefore the molar mass of CFC is 138.57 g/mol.
