I have a low molecular weight phenol unknown that is impure (light brown in colo

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Explanation / Answer

If it's a low molecular weight phenol and soluble in water, means that your unknown phenol is very polar and so water can actually disolve it. So if the phenol is polar, then you just need to use a non polar solvent like CCl4, or even hexane to recrystallize this compound.

The principle for recristallizing, is to find a solvent which your compound is insoluble at room temperature but at high temperatures is soluble. This is the ideal solvent.

The active carbon is used only to absorbs impurities if they are colored in the sample once you recristallize the compound. If iyou don't have a coloured impurity, then, the recristallization process should be fine.

Now, what will happen if you use non polar solvent, and your compound does not solve at high temperatures? just don't worry, this just mean that your compound has another behavior. To solve this, just use a solvent mix between the solvent in which is insoluble and the solvent in which is soluble. For example water-hexane or water-CCl4. You can also try with methanol - hexane. In that way, your compound will cristallize and you will get a more accurate melting point.

Hope this helps

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