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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: Computerized on August 23, 2009, 07:08:17 PM

Title: Which has the lowest freezing point?
Post by: Computerized on August 23, 2009, 07:08:17 PM
18. Which of the following solutions has the lowest freezing point?

(A) 0.20 m C6H12O6, glucose
(B) 0.20 m NH4Br
(C) 0.20 m ZnSO4
(D) 0.20 m KMnO4
(E) 0.20 m MgCl2 

Title: Re: Which has the lowest freezing point?
Post by: Borek on August 24, 2009, 02:48:34 AM
Please read forum rules (http://www.chemicalforums.com/index.php?topic=33740.0).
Title: Re: Which has the lowest freezing point?
Post by: Computerized on August 24, 2009, 09:28:36 PM
Well, I thought it was E because it dissolves into 3 ions, whereas all the others dissolve into 2 or less. Am I correct?
Title: Re: Which has the lowest freezing point?
Post by: MrTeo on August 25, 2009, 01:24:37 AM
Right, in fact when you work with the same kind of solutions (same solvent, so same Kcr and same molality) the only thing that varies the final value is the number of ions got from dissociation ((https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fwww.forkosh.dreamhost.com%2Fmimetex.cgi%3F%7B+%5Calpha+%7D&hash=46de7177512cb8002a15acfc27ce7c4a))

(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fwww.forkosh.dreamhost.com%2Fmimetex.cgi%3F%7B+%5CDelta+t%3DK_%7Bcr%7D+%5Ccdot+m+%5Ccdot+%5Cleft%28+%7B1+%2B+%5Calpha+%7D+%5Cright%29+%7D&hash=64a6eba9896d307ba0f68b78182dc62e)