Thanks Robin. I think the H2O formation enthalpy figure I quoted is for 1 atm and 25°C as I wrote (someone kindly confirm), but indeed those conditions are not STP (which is 1atm and 0°C as you say), my mistake.
Replace 'STP' by 'reference'. Michel ----- Original Message ----- From: "Robin van Spaandonk" <[EMAIL PROTECTED]> To: <vortex-l@eskimo.com> Sent: Thursday, March 15, 2007 10:28 PM Subject: Re: [Vo]: Re: JHS questions on evolved gas energy in CF In reply to Michel Jullian's message of Wed, 14 Mar 2007 11:19:31 +0100: Hi, [snip] >Please note that the -285.83 kJ/mol reaction enthalpy this calculation is >based on is for STP conditions 1atm and 25°C, so for different conditions e.g. >1atm and 100°C the appropriate reaction enthalpy must be used and will yield a >different thermo-neutral voltage value. Most definitions of STP that I am aware of use 0 C as the temperature, though according to Wiki, there is an old US version that uses 60 F (15.56 C). See http://en.wikipedia.org/wiki/Standard_conditions_for_temperature_and_pressure Regards, Robin van Spaandonk http://users.bigpond.net.au/rvanspaa/ Competition (capitalism) provides the motivation, Cooperation (communism) provides the means.
