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Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: o0CY0o on February 15, 2009, 03:53:42 AM

Title: 1st law of thermodynamic
Post by: o0CY0o on February 15, 2009, 03:53:42 AM

I'm an undergraduate yr 1 student.
I'm facing some problem in studying physical chemisty.
The part for thermodynamic.
I clearly understand how the things are derived.
Yet, I cannot figure the situation problems.
Can practise help?




I got a question which i found on the web and want to share with you guys.

The value of C(constant pressure) for a sample of a perfect gas was found to vary with temperature according to the expression C=20.17+0.3665T where T is tempreature in Kelvin. Calculate q,q,delta U and delta H for 1 mol of gas raised from 25 degree C to 200 degree C at constant pressure

Title: Re: 1st law of thermodynamic
Post by: Yggdrasil on February 15, 2009, 01:07:38 PM

Well, since the process occurs at constant pressure, you can immediately say something about q, ΔU and ΔH.  Also, to solve for one of these quantities, because C_p varies with temperature, you'll need to convert one of your formulas into an integral over dT.