I have and unknown compound(color is a light brown) that is a low mw carboxcylic

Question

I have and unknown compound(color is a light brown) that is a low mw carboxcylic acid but it is impure. The lab didn't have the right solvent to do a recrystallization, so I used 1 gram of unknown in 10ml of water. Some of the water evaporated off and I collected the crystals (still light brown). I want to get the unknown pure. Should I do an extraction(my compound is still dissolved in water)? And if so, what are the steps to get back my unknown in pure form? I need to get an accurate melting point. I have and unknown compound(color is a light brown) that is a low mw carboxcylic acid but it is impure. The lab didn't have the right solvent to do a recrystallization, so I used 1 gram of unknown in 10ml of water. Some of the water evaporated off and I collected the crystals (still light brown). I want to get the unknown pure. Should I do an extraction(my compound is still dissolved in water)? And if so, what are the steps to get back my unknown in pure form? I need to get an accurate melting point.

Explanation / Answer

If the compound is soluble in water, remove impurities by adding aqueous alkali and decolourize using charcoal, filter off the charcoal and extract it using diethyl ether. Dry the extract with sodium sulphate and then allow the ether layer to evaporate off. repeated cryatallization could give pure compound so that we can get accurate melting point

If water is the only reagent available, dissolve the compound in water add charcoal stirr and heat it for a while. Filter off charcoal evaporate water on a water bath till cryatallization point is reached then all to crystalize. Repeatd crystallization gives pure crystals of the carboxylic acid.

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