So a crystallization experiment was performed using an impure sample of biphenly, it weights 0.5g and contains about 5% impurity. Benzene is used as the solvent but after crystallization only about 0.02g were found. If everything was performed correctly, there are no spills, and very little solid was lost why is the recovery so low?
The low recovery in this crystallization experiment could be attributed to a few possible reasons:
1. Inefficient Solubility: Biphenyl may have low solubility in the solvent (benzene) at the chosen temperature. This could result in only a small amount of biphenyl actually dissolving in the solvent during the experiment.
2. Selective Crystallization: If the impurities have higher solubility in benzene compared to biphenyl, they may have remained in solution while the biphenyl crystallized out. This could result in a lower recovery of biphenyl.
3. Loss during Filtration: It is possible that some of the biphenyl crystals were lost during the filtration process. This can occur if the filtration apparatus is not properly set up or if some crystals accidentally pass through the filter.
4. Human Error: Despite your statement that everything was performed correctly, there is always a possibility of human error. This may include incorrect measurements, incorrect temperature control, or errors in the experimental procedure, which can lead to a lower recovery.
Overall, the low recovery in this crystallization experiment could be due to inefficient solubility, selective crystallization, loss during filtration, or human error.
The low recovery of the biphenyl crystals in the experiment can be attributed to a few possible reasons:
1. Solubility of impurities: Biphenyl is the desired compound to be recovered, while impurities are present in the impure sample. However, it is possible that the impurities have higher solubility in the solvent (benzene) compared to biphenyl. As a result, during the crystallization process, the impurities may have remained dissolved in the solvent, leading to a lower recovery of biphenyl.
2. Loss during filtration: Filtration is often employed to separate the solid crystals of the desired compound from the solution. If the crystals are very small or fragile, they may be lost or dissolved in the solvent during the filtration process. This can result in a lower recovery of biphenyl.
3. Loss during drying: After filtration, the crystals are typically dried to remove any residual solvent. If the crystals are not handled carefully or exposed to excessive heat, they may be lost or decompose, leading to a lower recovery of biphenyl.
4. Experimental error: Despite careful execution of the experiment, human error can sometimes occur. This may include incorrect measurements, improper technique during crystallization, or inaccurate weighing of the final product, which can contribute to a lower recovery.
To further investigate the cause of low recovery in this specific experiment, it would be useful to review the experimental details, such as the procedure followed, any observations during the process, and ensure that accurate measurements were taken throughout.