Tell how each of the following experimental errors will affect your ex- perimental results (yield, purity,...

Tell how each of the following experimental errors will affect your ex- perimental results (yield, purity, or both), and explain why. (a) You failed to dry the product completely. (b) You used enough water to recrystal- lize phenacetin, but your unknown was acetanilide. (c) In Experiment 2, you didn’t extract all of the aspirin from the dichloromethane solution. please answer the following questions with good explantion and structure if there are sturcutres.

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Expert Solution

a) If the product is not dried properly, then water will remain trapped in the product. Therefore, the product will definitely register a higher mass (higher yield) and hence, the percent purity (defined as the actual mass of the product divided by the theoretical mass) will be high.

b) The structures of phenacetin and acetanilide are given below.

phenacetin

acetanilide

Due to the presence of –OCH₃ group in phenacetin, phenacetin is less soluble in water than acetanilide. Consequently, if more water is used to re-crystallize the product (which was actually acetanilide), a greater proportion acetanilide will dissolve in water and will be lost. Thus, the yield of the product will be lower than expected.

c) Aspirin is an organic acid and hence, more soluble in water. However, being an organic compound, aspirin is soluble in dichloromethane as well. Consequently, if aspirin is not completely extracted from dichloromethane, then some amount of aspirin is lost with dichloromethane. Thus, the product will have a lower yield and hence, purity.

queen_honey_blossom answered 1 year ago

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