How to Calculate the Mass of Steam in a Closed Vessel?

Calculating the Mass of Steam

To calculate the mass of steam in the vessel, we need to first calculate the volume occupied by the steam and then use the ideal gas law to find the mass of the steam.

The dryness fraction (x) is defined as the ratio of the mass of the steam to the total mass of the wet steam. Using the given dryness fraction of 0.71 and total volume of the vessel as 1.07 m3, we can calculate the volume of the steam as 0.7597 m3.

Next, we can use the ideal gas law equation PV = mRT to calculate the mass of the steam. Given that the pressure of the steam is 8 MPa (which is converted to 8 * 10^6 Pa), volume as 0.7597 m3, and assuming a temperature of 373.15 K (100°C), we can find the mass of the steam in moles.

Finally, converting the mass in moles to kilograms by multiplying it with the molar mass of steam (approximately 18.01528 g/mol) and rounding the result to the nearest gram, we can determine the mass of steam in the closed vessel.