{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

EMon08MW

# EMon08MW - Thermodynamics CH 3510 Monday September 8 Law of...

This preview shows pages 1–10. Sign up to view the full content.

1 Thermodynamics CH 3510 Monday September 8 Law of Corresponding States Introduction to the FLOT

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
2 The Equation We said the pressure predicted by the ideal gas equation is too high because of attractive forces and the volume is too low because of molecule size. To make the ideal gas equation more accurate we can include two terms: ( 29 nRT nb V V an P = - + ) 2 2 a is the proportionality constant for the attractive force term. b is a measure of the excluded volume and is dependent on the amount of gas n. It should be emphasized that the constants a and b are empirical. When V is large, the equation becomes PV = nRT
3 “So what difference does it make?” “William, it was really nothing” The Smiths If 1 mole of methane occupies 250 mL at 0 °C what is the pressure? (a = 0.2273 Pa m 6 mol -2 , b = 4.307 x 10 -5 m 3 mol -1 ) ( 29 Pa 10 33 . 7 10 64 . 3 10 0969 . 1 10 25 . 0 2273 . 0 10 307 . 4 10 25 . 0 273 314 . 8 6 6 7 2 3 5 3 2 × = × - × = × - × - × × = - - = - - - P V a b V RT P Pa 10 08 . 9 10 25 . 0 273 314 . 8 6 3 × = × × = = - V nRT P Ideal gas van der Waals

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
4 The Critical Point Thomas Andrews (1813-1885) investigated the liquefaction of gases. He determined that there was a temperature above which a gas could not be liquefied. Increasing the pressure does not liquefy the gas. Experimentally it is observed that the boundary between the gas and the liquid disappears. The state of matter is called a super critical fluid. On the next slide you can see that at this temperature there is a point of inflection in the PV curve.
5 Experimental Isotherms for Carbon Dioxide See section 16.3 McQ. & S These lines are called isotherms In the blue shaded region gas and liquid coexist with each other. At any point outside of this region only one phase exists.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
6
7 Van der Waals Isotherms Figure 16.8 McQ. & S.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
8 1 (29 P T V dT 2 ( 29 P V T dV
9 van der Waals Equation and the Critical Temperature At the critical temperature there is a point of inflection in the P V curve.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 26

EMon08MW - Thermodynamics CH 3510 Monday September 8 Law of...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online