What could impact both the purity and percent recovery of the recrystallized product?

What could impact both the purity and percent recovery of the recrystallized product?

• A. Using the wrong solvent
• B. Not drying the crystals completely
• C. Heating the crystals too long
• D. Cooling the solution too fast

Answer: (B)

The statement regarding the impact of not drying the crystals completely on both the purity and percent recovery of the recrystallized product is accurate. When crystals are not dried thoroughly, solvent remnants can alter their weight, leading to an inflated percent recovery figure. This also affects purity, as the presence of solvent can contribute to the presence of impurities or dilute the desired product, thus compromising the overall quality. In recrystallization, achieving high purity typically involves careful drying. If any solvent remains, it could mask the true amount of product obtained, making it seem like more product was recovered than was actually isolated. Additionally, residual solvent can introduce contaminants that might not be present in the pure compound, thereby negatively impacting the purity. Similar impacts are seen from the improper choice of solvent, excessive heating, or rapid cooling, but these factors primarily affect the ultimate purity through different mechanisms. For instance, using the wrong solvent could prevent proper crystallization or solvent characteristics (like solubility) could affect purity but might not directly alter recovery measurements as dramatically as incomplete drying. Thus, complete drying is crucial as it directly ties into both the quantitative and qualitative aspects of the recrystallized product.

The statement regarding the impact of not drying the crystals completely on both the purity and percent recovery of the recrystallized product is accurate. When crystals are not dried thoroughly, solvent remnants can alter their weight, leading to an inflated percent recovery figure. This also affects purity, as the presence of solvent can contribute to the presence of impurities or dilute the desired product, thus compromising the overall quality.

In recrystallization, achieving high purity typically involves careful drying. If any solvent remains, it could mask the true amount of product obtained, making it seem like more product was recovered than was actually isolated. Additionally, residual solvent can introduce contaminants that might not be present in the pure compound, thereby negatively impacting the purity.

Similar impacts are seen from the improper choice of solvent, excessive heating, or rapid cooling, but these factors primarily affect the ultimate purity through different mechanisms. For instance, using the wrong solvent could prevent proper crystallization or solvent characteristics (like solubility) could affect purity but might not directly alter recovery measurements as dramatically as incomplete drying. Thus, complete drying is crucial as it directly ties into both the quantitative and qualitative aspects of the recrystallized product.