Describe the process you would have used to recrystallize the naphthalene.
To recrystallize naphthalene, here is a step-by-step process you can follow:
1. Begin by selecting a suitable solvent for recrystallization. In the case of naphthalene, a common and effective solvent is ethanol. It is important to choose a solvent in which the compound is soluble at high temperatures but insoluble or only slightly soluble at low temperatures.
2. Measure a specific quantity of naphthalene that you wish to recrystallize. This can be done by weighing it on a balance.
3. Transfer the measured amount of naphthalene into a heat-resistant container, typically a beaker or Erlenmeyer flask.
4. Add a small volume of the selected solvent (ethanol) to the container containing naphthalene. The volume of the solvent should be enough to dissolve the compound when heated, but not excessive.
5. Set up a heating apparatus, such as a hot plate or Bunsen burner, and place the container with naphthalene and solvent on it. Warm it gradually until the naphthalene dissolves completely. Stirring the mixture gently with a glass stirring rod can help to facilitate dissolution.
6. Once all the naphthalene has dissolved, remove the heat source and allow the solution to cool slowly at room temperature. Avoid rapid cooling, as it may lead to the formation of tiny crystals or impurities trapping within the crystal lattice.
7. As the solution cools, the solubility of naphthalene in ethanol decreases, causing it to recrystallize. Crystals will start to form. For faster crystallization, you can induce nucleation by scratching the inside surface of the container with a glass rod. The newly formed crystals act as seeds for further crystallization.
8. After complete cooling, collect the formed crystals by filtration. Using a Büchner funnel or filter paper placed in a funnel, filter the solution to separate the crystals from the solvent. The crystals will be collected on the filter paper, while the solvent (ethanol) passes through.
9. Rinse the collected crystals with a small amount of cold ethanol to remove any impurities or residual solvent. This rinse step helps to improve the purity of the crystals. Be cautious not to over rinse, as it may cause loss of desired product.
10. Lastly, dry the crystals to remove any remaining traces of ethanol. This can be done by placing the crystals on a watch glass or in an oven set at a low temperature until they are completely dry.
Congratulations! You have successfully recrystallized naphthalene, isolating pure crystals through this purification technique.