Find mass of steam using the 'Ideal Gas Equation'.

[Lenstonbain]

Show that there is a mass of (4.8 x 10^-3)kg of steam above the water when the temperature is 122 celsius?

Volume of Steam = 4.2 x 10^-3 (metres cubed)

Pressure of steam= 2.1 x 10^-5 (Pa)

molar mass of water = 18g per mole

molar gas constant = 8.3 Joules/mol/K

Homework Equations

pV= nRT

The Attempt at a Solution

The mass of steam given in the question doesn not come out of this equation whenever I input the numbers and I do not know why. I have made sure I used the correct units, i.e. 122 celsius is 395 Kelvin, and 18g is 0.018 kg, but the answer still does not work out.

Could somebody please show me the working that gives the correct steam mass as given in the question.

Thanks in advance for any help

 

[rock.freak667]

Post your working on how you did the problem. Perhaps you just made an error in calculation, without posting what you did, we won't know whether or not you were on the right track.