Question

The specific volume of water vapor at 150 kpa and 120 c is 1.188 m3/kg. determine the molar-specific volume and the density of the water vapor

Answer 1

Given:
Specific volume = 1.188 m³/kg
Pressure, p = 150 kPa
Temperature, T = 120 C

The mass density is
ρ = 1/(1.188 m³/kg) = 0.8418 kg/m³

The ideal gas law is
pV = nRT
where
V = volume,
p = pressure,
n = numbe pf moles,
T = temperature
R = 8.314 J/(mol-K), the gas constant

The molar specific volume is

`V_(n) = (V)/(n) = (RT)/(p) \\ = ((8.314 \, (J)/(mol-K))(120+273 \, K) )/(150 * 10^(3) \, (N)/(m^(2)) ) \\ = 0.0234 \, (m^(3))/(mol)`

Answer:
The molar specific volume is 0.0234 m³/mol.
The density is 0.842 kg/m³