This is an archived, read-only copy of the United-TI subforum , including posts and topic from May 2003 to April 2012. If you would like to discuss any of the topics in this forum, you can visit Cemetech's Technology & Calculator Open Topic subforum. Some of these topics may also be directly-linked to active Cemetech topics. If you are a Cemetech member with a linked United-TI account, you can link United-TI topics here with your current Cemetech topics.

Math and Science => Technology & Calculator Open Topic
Author Message
Newbie

Bandwidth Hog

Joined: 23 Jan 2004
Posts: 2247

 Posted: 25 Apr 2010 04:09:23 pm    Post subject: I'm having a tough time understanding Entropy. The question I'm having difficulty with is: 10 kg of water at 0 C is mixed with 10 kg of water at 100 C. The change in entropy (in cal/K) of the system is? Is there a general equation to this? Edit: The equation I found was the integration of T1 to T2 dQr/T. Now I'm just a little confused on dQ.Last edited by Guest on 25 Apr 2010 04:36:39 pm; edited 1 time in total
thornahawk
μολών λαβέ

Active Member

Joined: 27 Mar 2005
Posts: 569

 Posted: 25 Apr 2010 07:05:41 pm    Post subject: Well, the trick of course is how you'd express dQ in terms of dT. You might find the heat capacity of water (for which phase(s) of water, you'll have to figure out, but what is so special about those given temperatures?) to be a useful quantity in your calculations. However, it is the change in entropy that is being asked of you, so think about whether you should be integrating or not. (What is a differential, anyway?) Finally, don't forget that all temperatures be in absolute units! Hope this helps. thornahawk P.s. Bonus exercise: what is the final temperature of your mix?
 Display posts from previous: All Posts Oldest FirstNewest First
Register to Join the Conversation
Have your own thoughts to add to this or any other topic? Want to ask a question, offer a suggestion, share your own programs and projects, upload a file to the file archives, get help with calculator and computer programming, or simply chat with like-minded coders and tech and calculator enthusiasts via the site-wide AJAX SAX widget? Registration for a free Cemetech account only takes a minute.

»
 Page 1 of 1 » All times are UTC - 5 Hours