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As part of an at-home lab, my chemistry class is creating cooling baths to measure the freezing point of different solutions. We have to determine the molar mass of the solutes in these solutions by observing the freezing point. The cooling bath is constructed from ice and salt inside a 500 mL beaker, into which are placed test tubes of solutions (one at a time). A thermometer sticking out of the test tube hypothetically measures the freezing point. The problem is that the ice bath is taking hours to freeze the solution.

To speed up this process, can I just stick the whole apparatus in the freezer and check it every 10 minutes or so to see the temperature at which the solutions freeze?

Will the freezing point of salt water and calcium chloride water (the solutions in question) be radically different if frozen in an ice bath vs. frozen inside a kitchen freezer?

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The freezing point remains the same, but its measured value may depend on the way of measurement.

In case the solution freezing point is too close to the ice/salt 3:1 bath temperatures, it may be the reason for too long freezing time. The bath ice/$\ce{CaCl2 . 6 H2O}$ bath 1:2 could help, if applicable.

Note that fast freezing may lead to biased value, especially, if supercooling occurs. E.g. a PET bottle with water can get supercooled in a freezer deep below the freezing point.

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