posted by Rachelle on .
What pressure would have to be applied to steam at 325°C to condense the steam to liquid water (ÄH vap = 40.7 kJ/mol)?
Dr bob please! Chemistry - GK, Friday, November 28, 2008 at 11:47pm
Use the Clausius-Clapeyron Equation to calculate the vapor pressure at 325°C. That is the pressure that must be applied to condense the steam at 325°C.
Ln(P2/P1) = (∆H/R)[(T2-T1)/T2T1]
P1 = 1 atm
∆H = 40700J
R = 8.3145 J/°K.mol
T2 = (325+273) = 598°K
T1 = (100+273) = 373°K
P2 = (unknown)
[NOTE: The pressure needed is quite high]
Dr bob please! Chemistry - Rachelle, Sunday, November 30, 2008 at 10:06pm
i solved for lnx=4,852,725
whats next? and i relaly cant put it into the calc. it says (overflow)
You must be punching the calculator wrong somewhere. By the way that was GK that gave you that answer in such nice detail. I worked the problem and end up with
ln P2 = 4.93777 and when I click on ex I get an answer. Your digits are about the same but the decimal point is way different.
If you want to type in your set up and the follow through I will check it for you step by step.