A storage Tank at STP

1. The problem statement, all variables and given/known data[/B]





a Storage tank at STP contains 18,5kg of nitrogen (N2). a) What is the volume of the tank? b) What is the pressure if an additional 15.kg of nitrogen is added without changing the temperature.





2. Relevant equations

n= m/molar mass

P= nRT/V



3. The attempt at a solution



For a) I got n= m/molar mass --> 18.5 X 1000 / 28 = 660.71 mol

1 mole occupies 22.4 L

--> V= 660.71 X 22.4 = 14 799.99 L 14.8 m^3



For b) I have T= 273.15 n= (18.5 +15) x 1000 /28= 1196 mol

i think for some reason V is assumed to be constant and doesnt change so ,

--> P= nRT/V, wich gives me 183.44 N/m^2



However in b the answerr is suppose to be 1.83 X10^5 Pa, or 183 X 10^ 3 Pa, ans I thought n/m^2 is the same units as Pa. I would like clarification, thanks