Thermodynamics and Fluid Mechanics Thermodynamics and Fluid Mechanics Physics Help Forum Oct 1st 2014, 02:29 PM #1 Junior Member   Join Date: Oct 2014 Posts: 2 Thermo: Calculate molar volume using steam tables and ideal gas law For water vapour, calculate the molar volume at 572 ºF and 145 psi(g), using the following two methods, steam tables and the ideal gas law. Is the water vapour acting ideally? Molar mass of 18 g/mol for water SOLUTION. 1. The problem statement, all variables and given/known data Given T=572 ºF, pressure= 145 psi (g) using the steam tables and ideal gas law Molar Mass= 18 g/mol for water Find: Is the water vapour acting ideally? 2. Relevant equations Ideal Gas Law: PV=nRT P is the pressure =145 psi (g) V is the molar volume n= mol R= Ideal gas constant 8.314 J(K^-1)(mol^-1) T is temperature in kelvin, so temperature in farenheit= 572 ºF =573.15 ºK How can I calculate the molar volume using the steam tables? and how can I know if the water vapour is acting ideally? 3. The attempt at a solution Ideal gas law: PV= nRT so: V= nRT/P= (18 mol)(8.314 JK^-1mol^-1)(573.15 ºK)= 85773.04=8.5x10(^4) metres cube where: P= 145 psi (g)= 999739.80705 Pascals 1 Psi = 6 894.75729 Pascals Last edited by ariana; Nov 13th 2014 at 03:06 AM. Reason: ADD INFO  Tags thermodynamics Thread Tools Show Printable Version Email this Page Display Modes Linear Mode Switch to Hybrid Mode Switch to Threaded Mode Similar Physics Forum Discussions Thread Thread Starter Forum Replies Last Post abcde Advanced Thermodynamics 2 Sep 12th 2014 02:43 PM KAJ0989 Advanced Thermodynamics 1 Dec 24th 2012 07:44 PM CNM DESIGN Thermodynamics and Fluid Mechanics 0 Aug 22nd 2010 04:35 PM cowcow8866 Thermodynamics and Fluid Mechanics 0 Mar 6th 2010 05:53 AM AJEY Thermodynamics and Fluid Mechanics 1 Dec 15th 2009 10:12 PM