# Search results

1. ### Quantum Chemistry/Mechanics Graduate Study

Hi all, I've been studying chemical engineering for three years now and will be entering my senior and final year next year. This year I found my quantum chemistry/mechanics course very interesting and enjoyable. I also found that I'm pretty good at it. I feel like I might be more...
2. ### Enthalpy of Formation

its possible but you need to use another enthalpy term that accounts for the latent heat which is from the phase transfer of liquid to gas
3. ### Molar Volume and Molal Volume

The exact question I have to answer isn't about Molar and Molal volume but I need molal volume to plug into the equation for diffusivity coefficients. I have the molar volume of vitamin E 603cm^3/mol and its MW 430.7 and I need to find its molal volume cm^3/(g*mol) but I'm getting pretty...
4. ### Thermodynamics Entropy +2nd law problem

although pressure cannot be specific is this calculation of pressure correcT? what I mean is will the pressure calculated here work for the rest of the problem? also how do I know this is an isentropic process
5. ### Thermodynamics Entropy +2nd law problem

thank you very much I got it.
6. ### Thermodynamics Entropy +2nd law problem

Homework Statement Propane at 350 degrees Celsius and 600cm^3 / mol is expanded in a turbine. The exhaust is atmospheric. What is the lowest possible exhaust temperature? How much work is obtained? You may assume ideal gas behavior and the heat transfer to the surroundings is negligible...
7. ### Making money

to the person saying the real world is a piece of cake you should really think about that, just because your job is so accommodating don't think everyone is so fortunate. Trying working 2 jobs to support your family, and I don't mean office jobs I mean manual labor or construction see how...
8. ### Thermodynamics Entropy question

thanks a lot !
9. ### Thermodynamics Entropy question

so to get Q i do use the integral of C from 373 to 280 and then i take that and put it over T and do an integral from 373to 280 dT right?
10. ### Thermodynamics Entropy question

I worked out a solution let me see what you think(i was thinking something sorta like what you said) I said change in internal = Q and changein internal is the integral from 373 to 280 of the C for copper which is 2.723/8.314(which is R) in my book dT (my book gives C's in Cp/R for some reason)...
11. ### Thermodynamics Entropy question

Homework Statement A 10-kg block of copper is initially 100 degrees celsius. It is thrown into a very large lake that is 280K. What is the entropy change of the piece of copper. What is the entropy change of the universe? Homework Equations The Attempt at a Solution I know that...
12. ### Wronskian help

...wow I am an idiot! thanks I got it to simplify to 0 now haha sigh.
13. ### Wronskian help

Homework Statement take the wronskian of [cos(theta)]^2 and 1+cos(2theta) Homework Equations The Attempt at a Solution so I set up the determinant [cos(theta)]^2 1+cos(2theta) as my y1 and y2 respectively and -2cos(theta)sin(theta) and -sin(2theta) as my y1 and y2 prime...
14. ### Thermodynamic pressure/temperature question

Homework Statement Consider filling a cylinder of compressed argon from a high-pressure supply line. Before filling, the cylinder contains 10 bar of argon at room temperature the valve is then opened, exposing the tank to a 50 bar line at room temperature until the cylinder reaches 50bar...
15. ### Quality and percent volume

Homework Statement A rigid container of volume 1 m^3 contains saturated water at 1MPa. If the quality is .10, what is the volume occupied by the vapor. Homework Equations The Attempt at a Solution I wanted to use the equation v=(1-x)(v_l)+x(v_v) where all v's are specific...
16. ### Boiling point on top of mount everest

its from a problem in my book engineering and chemical thermodynamics by milo koretsky its in a homework problem it just says remember hte equation for pressure based on altitude is : and has it but i have never seen it before.
17. ### Boiling point on top of mount everest

hey I understand to use the equation for pressure but I'm just confused on what Temperature to put into it can anyone help?
18. ### Boiling point on top of mount everest

what temperature would i put in though 373 K? (normal boiling temp of water?)
19. ### Boiling point on top of mount everest

Homework Statement At what temperature does water boil on the top of mount everest, elevation z = 8848m? Recall that the dependence of pressure with altitude is give by: P=P_atm * exp(-MWgz/RT) MW=molecular weight of the gas, P_atm =atmospheric pressure, g is the gravitational...
20. ### Confusion in Stoke's theorem!

oh that makes sense thanks the other definitions I found online I couldn't really understand but this clears it up well.
21. ### Confusion in Stoke's theorem!

thanks a lot for clearing this up one more thing, just exactly how could I tell the differnece between a scalar function and a vector function?
22. ### Confusion in Stoke's theorem!

Homework Statement Hello, this isn't a specific problem but a part I am confused about in Stoke's theorem. In my text the section on Line integrals (if C(t) is the parameterization of the curve) as the integral of F(C(t))*C'(t) but for vector fields the formula becomes the integral of...
23. ### Surface Integrals of Vector Fields question

ooo, sigh you are correct thanks a lot for the help I feel really stupid now hahah
24. ### Surface Integrals of Vector Fields question

oh by the way the book got sin(phi)*<cos(theta)sin(phi),sin(theta)sin(phi),cos(phi)> for the cross product.
25. ### Surface Integrals of Vector Fields question

ah ok well that makes me feel better than because my prof won't care about simplification, I had the same feeling as you about me not seeing it so I just went ahead and calculated the integral out but I got a different answer. And I got the other problems in the set correct, I just wanted to be...
26. ### Surface Integrals of Vector Fields question

Sorry if I caused confusion I typed that mess up fast cause I didn't want you to think I wasn't going to respond, I am saying mine and the text's answer vary because of what we got for the cross products. I have the same exact thing as the text for the Parametrization and the Vector field...
27. ### Surface Integrals of Vector Fields question

hey thanks, my surface I have parameterized as (3cos(theta)sin(phi),3sin(theta)sin(phi),3cos(phi)) 0<theta<2pi 0<phi<pi/2 the cross product came out to 9sin(phi)*<cos(theta)sin(phi),sin(theta)sin(phi),cos(phi)> I didn't actually do this cross product but in the chapter of my text the normal...
28. ### Surface Integrals of Vector Fields question

Homework Statement F=<0,3,x^2> computer the surface integral over the hemisphere x^2 + y^2 + z^2 = 9 z greater than or equal to 0, outward pointing normal. Homework Equations The Attempt at a Solution I don't know why I keep getting this problem wrong. The general formula for...
29. ### Does Better Memory=Better Grades?

hahah oh wow I did not see the date! which brings me to the question of how I ended up at this topic at all...oh well
30. ### Is there a liquid which is attracted by magnet at room temp.

do you mean the liquid is at room temperature? I'm pretty sure liquid oxygen is but that would be very cold :-/