Thermodynamics Quiz: Check Your Understanding

[Shackleford]

This is an open-whatever take-home homework quiz. Could someone check my work? Thanks.

www.freebibleproject.com/quiz.html[/URL]

 

[dynamicsolo]

Sorry, but your link is giving a 403 message. The site may not be permitting direct linking to .jpgs (tried both clicking and copy-and-pasting...).

You may need to link to a specific page at the site or use some other free-host...

 

[Shackleford]

Sorry, but your link is giving a 403 message. The site may not be permitting direct linking to .jpgs (tried both clicking and copy-and-pasting...).

You may need to link to a specific page at the site or use some other free-host...

That's my site. Try it again. I just made an html page. Thanks.

 

[dynamicsolo]

OK, now I'm getting the page, but a "red X", instead of your .jpg . (That could be a problem with my browser, though...)

 

[Shackleford]

OK, now I'm getting the page, but a "red X", instead of your .jpg . (That could be a problem with my browser, though...)

Could you do right click and save as?

http://www.freebibleproject.com/quiz.jpg

 

[dynamicsolo]

All right, still isn't working for me. I'm on a Mac, so I don't "right-click", but I can download and save to the desktop. It downloaded 8K of something, but I can't read it. Are you sure the image is formatted as a .jpg ? (Just giving something a .jpg file extension doesn't make it one...).

If you have set it up correctly, I may have to bow out, as my antique home machine may not be dealing with this... (If so, my apologies.)

 

[Shackleford]

All right, still isn't working for me. I'm on a Mac, so I don't "right-click", but I can download and save to the desktop. It downloaded 8K of something, but I can't read it. Are you sure the image is formatted as a .jpg ? (Just giving something a .jpg file extension doesn't make it one...).

If you have set it up correctly, I may have to bow out, as my antique home machine may not be dealing with this... (If so, my apologies.)

It's a jpeg. Shoot me an email address, and I'll just send it to you, or something. I have AIM, too.

 

[dynamicsolo]

Shoot me an email address, and I'll just send it to you, or something. I have AIM, too.

If you click on my name on my posts, you will get taken to my "profile page". Try sending the image as an attachment on a private message AND go to the Contact Info near the bottom of the page and click on the link to send me an e-mail. We'll see (if only for future reference) if that works...

 

[Shackleford]

If you click on my name on my posts, you will get taken to my "profile page". Try sending the image as an attachment on a private message AND go to the Contact Info near the bottom of the page and click on the link to send me an e-mail. We'll see (if only for future reference) if that works...

I didn't see the option to attach an image in the PM.

Try this.

https://www.physicsforums.com/attachment.php?attachmentid=14379&d=1213489081

 

[dynamicsolo]

The forum didn't like your attachment...

And sorry about the PM: attachments work for some forum types, but not this one, I guess.

Go to my profile and try the e-mail link (I'm curious to see what works around here...).

 

[Shackleford]

The forum didn't like your attachment...

And sorry about the PM: attachments work for some forum types, but not this one, I guess.

Go to my profile and try the e-mail link (I'm curious to see what works around here...).

That's weird. I see the attachment.

I just tried to send an email through the forums.

 

[dynamicsolo]

I got your e-mail. Try sending your image there.

 

[Shackleford]

I send it.

 

[dynamicsolo]

OK, I've looked over your answers. The only question I have about #1 is that you calculated that 150 gm. of Na2O2 is 1.92 mole, but then multiplied the 143.5 kJ/mole by half that amount. Am I not understanding the definition?

#2, 3, and 4 looked fine.

I'm going to suggest that you post this also to the 'Other Sciences' section of the Homework Forum because #5, 6, and 7 are really chemical thermodynamics. While I understand the basic idea for those calculations, I'd have to take your word for the delta_S's involved and how the results of calculations are interpreted. I think for those problems, you'd be safer in consulting with someone more familiar with the chemistry.

For convenience (so you don't have to go through yesterday's adventure again), I've uploaded your image to my album on ImageCave. You are welcome to post the link in your other post:

http://usera.imagecave.com/dynamicsolo/shacklefordquiz.jpg

 

[Shackleford]

From the equation, the change in enthalpy of 143.5 kJ/mole is for two moles of Na2O2. That's why I multiplied (1.92/2) times the given change in enthalpy value to reflect that. Four moles would give twice the change in enthalpy value and so on.

Heh. I actually did post this in Other Sciences first, but someone has still yet to respond. Thanks for your help. I'll probably be posting these as we get them.

 

[dynamicsolo]

From the equation, the change in enthalpy of 143.5 kJ/mole is for two moles of Na2O2. That's why I multiplied (1.92/2) times the given change in enthalpy value to reflect that. Four moles would give twice the change in enthalpy value and so on.

I guess that's what puzzles me. The delta_H is given in kJ/mole , not kJ for the entire reaction. Perhaps I should ask what it is that the enthalpy change is being given per mole of.

Heh. I actually did post this in Other Sciences first, but someone has still yet to respond. Thanks for your help. I'll probably be posting these as we get them.

I don't know offhand how many helpers read that section of the Forum. It may be that you didn't get responses because of the problem with the link to your quiz image. You're welcome to use my link in your post over there; maybe you'll get a bite this time...

 

[physixguru]

The 90 percent of post has turned from a chemistry quiz to computer e-mailing skills.