My Chemistry Tutor
March 12, 2010, 03:36:13 PM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with username, password and session length
Unlimited Game Rentals Delivered - Free Trial
News:
 
   Home   Help Search GoogleTagged Login Register  


Pages: [1]
  Print  
Author Topic: Finding Vapor Pressure Question (Raoult's Law?)  (Read 128 times)
ArtemisFei
Labrat
*
Posts: 2


View Profile
« on: February 03, 2010, 01:45:46 PM »

Alright, so for a problem in my class, it seems I'm pretty much stuck.

10g of a certain non-volatile non-electrolyte was dissolved in 100g of water at 20.0 degrees Celcius. The V.P. was lowered from 17.535 mm Hg to 17.235 mm Hg. What is the molar mass of the solute?

Alright, now, I'm assuming that Raoult's Law is used for this equation. Since the VP was given with the solute added, I'm assuming I use 17.235 mm Hg. So that takes care of the P1°. However, what do I use to plug in for the particle pressure if I'm effectively solving for the mol ratio, and therefore the molar mass?

Do I use the other given 17.535?

Or...is this even a Raoult's Law Question at all?
Logged
ArtemisFei
Labrat
*
Posts: 2


View Profile
« Reply #1 on: February 03, 2010, 02:16:59 PM »

Whoa whoa. I think I may have solved it. Go go perseverance.

So...what I did for the setup was:
17.235 = (5.55/5.55+x)(17.535)

Then I got 0.097 for the mol of the unknown and by diving that by the 10g, I got the molar mass as 103.09.

It...sounds correct. Haha.
Logged
Pages: [1]
  Print  

 
Jump to:  

* Share this topic...
In a forum
(BBCode)
In a site/blog
(HTML)

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!