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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: ale1998 on December 14, 2016, 01:05:55 PM

Title: Zinc freezing point depression
Post by: ale1998 on December 14, 2016, 01:05:55 PM

Hello,
I did an experiment on how different concentrations of ZnCl₂ affect the freezing point of demi water. My results were that till a concentration of about 10 mol dm^-3 the freezing point decreased (more or less in a linear manner). After that at concentrations of 15mol dm^-3 the freezing point started to increase again (approach 0 degrees Celsius again).

Attached in the file is a graph of the freezing point depression vs. the concentration of ZnCl₂ in demi water.
X-axis: concentration of ZnCl₂ in mol dm^-3
Y-axis: freezing point depression in Kelvin

Does anybody know why the freezing point depression initially decreases, and then past a certain concentration increases again?

Thanks in advance!

Ale1998

Title: Re: Zinc freezing point depression
Post by: mjc123 on December 14, 2016, 01:17:16 PM

Google "eutectic mixture"

Title: Re: Zinc freezing point depression
Post by: Vidya on December 15, 2016, 09:21:42 AM

Eutectic point or temperature
https://en.wikipedia.org/wiki/Eutectic_system