You work in a small-scale manufacturing facility that uses salicylic acid as the

Question

You work in a small-scale manufacturing facility that uses salicylic acid as the starting material for the synthesis of aspirin. Your company buys ~95% pure salicylic acid from a major manufacturer and purifies it in-house prior to its use in the synthesis of aspirin. You are given the job to purify 250g of the impure salicylic acid. You realize you know very little about this substance, so you decide to look it up. What specific information would you look for that would help you in devising your strategy for completing your purification task? Explain your strategy and the relevant rationale underlying this strategy.

Explanation / Answer

ok first, to purify any compound, I can actually do it in two ways. One by distillation (liquids) and the other by recristallization (solids). In this case, I'll do the recristallization technique.

recrystallization is a technique used to purify chemicals. By dissolving both impurities and a compound in an appropriate solvent, either the desired compound or impurities can be coaxed out of solution, leaving the other behind. It is named for the crystals often formed when the compound precipitates out.

So the first information I'll look for this acid is the solvent to use so I can dissolve the acid. The second I'll look is in waht solvent it can not dissolve at room temperature, but in hot temperatures it dissolves: This is actually the best thing because the method of recristallization states that one compound should be soluble in hot temperatures and remain insoluble in cold.

The third thing I'll look, in case I can't find one single solvent to recristallize the acid, I'll look for the solvents that this acids is not soluble, and then, do a mixing solvent that behaves like a single solvent.

Once I find that, I'll dissolve the acid in the solvent I found (or mix). Put it some heat so it can finish dissolve, and then, once is dissolved completely, I'll stop the heating and then, put it in an ice bath to cool down. This will actually works, because the solid will recristallyze pure, leaving any impurity behind. Then, I'll filter and use the acid to to the synthesis of the aspirin.

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