Go Back   Student Doctor Network Forums > Pre-Medical Forums > MCAT Discussions > MCAT Study Question Q&A

Notices

MCAT Study Question Q&A Subforum specifically for asking questions when studying for the MCAT.
Please no actual MCAT questions.
RSS: Feed Icon


Reply
 
Thread Tools Display Modes
Old 05-05-2012, 06:15 PM   #1
Senior Member
 
Join Date: May 2009
Posts: 125
SDN 2+ Year Member
Default BR question. Confusing~~


SDN Members don't see this ad. (About Ads)
Solute X does not dissociate once in solution. If another impurity were chosen instead that can dissociate into two particles in solution, how would the freezing point be affected?
A.) the freezing point will decrease by twice as much as expected, if the impurity does not dissociate.
B.) the FP would decrease by as much as expected, if the impurity does not dissociate.
C.) the freezing point would decrease by half as much as expected, if the impurity does not dissociate.
D.) the FP would be constant.


Anyone want to give an answer and their reason??

Last edited by chaser0; 05-05-2012 at 07:24 PM.
chaser0 is offline   Reply With Quote
Old 05-05-2012, 07:10 PM   #2
Senior Member
 
Join Date: Apr 2011
Posts: 193

Default

.

Last edited by Dasypus; 05-25-2012 at 07:27 AM.
Dasypus is offline   Reply With Quote
Old 05-05-2012, 07:20 PM   #3
Senior Member
 
Join Date: May 2009
Posts: 125
SDN 2+ Year Member
Default

Wait what? That doesnt make any sense.

A says it does NOT dissociate, meaning that the new solute has the same effect as the original solute X.
The FP shouldnt be any different at all between X and the new.
chaser0 is offline   Reply With Quote
Old 05-05-2012, 07:22 PM   #4
Senior Member
 
Join Date: May 2009
Posts: 125
SDN 2+ Year Member
Default

Oh and sorry I wrote the answer choices wrong.

Fixed it
B and C are exclusive
chaser0 is offline   Reply With Quote
Old 05-05-2012, 07:24 PM   #5
Senior Member
 
Join Date: Apr 2011
Posts: 193

Default

.

Last edited by Dasypus; 05-25-2012 at 07:28 AM.
Dasypus is offline   Reply With Quote
Old 05-05-2012, 07:27 PM   #6
Senior Member
 
Join Date: May 2009
Posts: 125
SDN 2+ Year Member
Default

Oh wait i think ur right.

The wording of the answer Choices are funny.
What they mean to say is:
The FP would decrease by twice as much compared to another experiment where the impurities did not dissociate.




So yeah, A haha
chaser0 is offline   Reply With Quote
Old 05-05-2012, 07:27 PM   #7
Banned
 
Status: Pre-Podiatry
MDApps: View Profile
Join Date: Dec 2011
Posts: 18,777

Default

Going with B. FP is a colligative property meaning that only the number of particles matters. If something doesn't dissociate then the vant hoff factor is 1. If something that can dissociate into two things, but doesn't dissociate in the solution given then the van't hoff factor is still 1.
MedPR is offline   Reply With Quote
Old 05-05-2012, 07:30 PM   #8
Senior Member
 
Join Date: May 2009
Posts: 125
SDN 2+ Year Member
Default

Yeah answer is A, the problem is just worded extremely poorly~~

I thought it was B too
chaser0 is offline   Reply With Quote

Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -7. The time now is 08:03 PM.


Comments are closed.