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 05-05-2012, 06:15 PM #1 Senior Member   Join Date: May 2009 Posts: 125 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.
 05-05-2012, 07:10 PM #2 Senior Member   Join Date: Apr 2011 Posts: 193 . Last edited by Dasypus; 05-25-2012 at 07:27 AM.
 05-05-2012, 07:20 PM #3 Senior Member   Join Date: May 2009 Posts: 125 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.
 05-05-2012, 07:22 PM #4 Senior Member   Join Date: May 2009 Posts: 125 Oh and sorry I wrote the answer choices wrong. Fixed it B and C are exclusive
 05-05-2012, 07:24 PM #5 Senior Member   Join Date: Apr 2011 Posts: 193 . Last edited by Dasypus; 05-25-2012 at 07:28 AM.
 05-05-2012, 07:27 PM #6 Senior Member   Join Date: May 2009 Posts: 125 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
 05-05-2012, 07:27 PM #7 Banned   Status: Pre-Podiatry MDApps: View Profile Join Date: Dec 2011 Posts: 18,777 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.
 05-05-2012, 07:30 PM #8 Senior Member   Join Date: May 2009 Posts: 125 Yeah answer is A, the problem is just worded extremely poorly~~ I thought it was B too

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