Is My Compound Pure Despite Low Percent Recovery?

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The discussion centers on the purity assessment of a recrystallized carboxylic acid, where a narrow melting point range suggests purity, yet a low percent recovery (< 40%) indicates significant impurities. The user seeks clarification on reconciling these conflicting results and understanding which metric is more indicative of purity. It is noted that percent recovery is calculated as the mass of pure compound divided by the mass of impure compound, which differs from percent yield. The conversation highlights the importance of both melting point and percent recovery in evaluating compound purity. Ultimately, understanding the context of these measurements is crucial for accurate purity assessment.
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Homework Statement


I recrystallized an unknown carboxylic acid, then found the melting point of the dried compound and identified it. The melting point range was narrow and that said to me that the compound was pure, but the percent recovery was very low (< 40 %). Indicating there was still a significant amount of impurities. I just wanted to know how to resolve these conflicting results and/or which contribution is the most important in determining purity. Forgive me if this question is stupid.



Homework Equations





The Attempt at a Solution

 
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yungwun22 said:

Homework Statement


I recrystallized an unknown carboxylic acid, then found the melting point of the dried compound and identified it. The melting point range was narrow and that said to me that the compound was pure, but the percent recovery was very low (< 40 %). Indicating there was still a significant amount of impurities. I just wanted to know how to resolve these conflicting results and/or which contribution is the most important in determining purity. Forgive me if this question is stupid.



Homework Equations





The Attempt at a Solution



By the " recovery " do you mean ( experimental yield / theoretical yield ) x 100 %?
 
No, the percent recovery. (mass of pure compound)/(mass of impure compound) x 100 %. I'd only heard of percent yield before this class, but this formula is what was given. Only to be used in purification processes.
 
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