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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: dja01 on September 13, 2019, 02:11:12 PM

Title: Separating components of mixture
Post by: dja01 on September 13, 2019, 02:11:12 PM

Just wondering, using the solutes of cold water, hot water, HCL (3M) and NaOH (3M), how could I separate AND recover the components of a mixture of benzoic acid and sodium sulfate? I have a few ideas, but I'm mostly looking to see if someone knows for sure.

Title: Re: Separating components of mixture
Post by: dja01 on September 13, 2019, 02:14:32 PM

Thought i should add my idea. Since Sodium sulfate and benzoic acid are both soluble in hot water, add the mixture to hot water. As the water cools down, the solubility of benzoic acid becomes poor, and would thus separate, while the sodium sulfate would remain in solution. My main confusion is that since all 3 things, the 2 solutes and the solvent, are liquids, how would you go about separating?

Title: Re: Separating components of mixture
Post by: AWK on September 13, 2019, 04:07:54 PM

Just check solubilities of both compounds at 0 C or RT (if you can't use the fridge) and 100 C. The addition of a small amount of strong acid will reduce the solubility of the weak acid. By the crystallization method, you will lose about 2-3 g of benzoic acid per liter of solution.