Question

Purification: Vacuum Filtration: order steps

a) Using cold distilled water, wash the remaining crystals out of the beaker into the Buchner funnel and rinse the crystals in the funnel.
b) Wet filter paper in the Buchner funnel with distilled water and turn the vacuum on.
c) After the vacuum has been on for a few minutes, turn off the vacuum, save the filtrate in case you need to precipitate more crystals.
d) Cool a wash bottle of distilled water in an ice bath.

Answer 1

The steps for vacuum filtration include wetting the filter paper and turning on the vacuum, dissolving and cooling the mixture to form crystals, washing the crystals with cold distilled water, and turning off the vacuum while saving the filtrate. Fractional crystallization and distillation are methods of purification based on solubility and boiling points, while home water purification techniques include reverse osmosis and other methods.

Step-by-step explanation:

The steps for vacuum filtration should be conducted in a proper order to ensure the purity of the compound. The order of steps for vacuum filtration in purification would be:

1. Wet filter paper in the Buchner funnel with distilled water and turn the vacuum on. This helps to ensure that the filter paper adheres to the funnel and provides an effective seal for the filtration process.
2. Dissolve the compound in a solvent and cool the mixture if required to precipitate the crystals.
3. Using cold distilled water, wash the remaining crystals out of the beaker into the Buchner funnel and rinse the crystals in the funnel. The cold distilled water aids in minimizing the solubility of the compound, thereby helping to wash out as much of the compound as possible without dissolving it.
4. After the vacuum has been on for a few minutes, turn off the vacuum, save the filtrate in case you need to precipitate more crystals. This is an important step as sometimes crystals may remain dissolved in the filtrate and could be recovered by further cooling.

Filtration is a key part of separating mixtures in chemistry. Specifically, fractional crystallization relies on differences in solubility at different temperatures, and impurities being more soluble, to separate a desired compound from a solution. In contrast, techniques like distillation separate components based on differences in boiling points. For water purification at home, methods such as distillation, boiling, reverse osmosis, water softeners, or filtration can be used based on the specific contaminants present in the water supply.