Notes
new beaker. Think about if you want to take the mass of the new beaker
before pouring the liquid into it. Rinse the solid with more boiling distilled
water and add that to the new beaker as well.
- Once the liquid in the new beaker is cool to the touch, place that beaker in an
ice bath for 15 minutes to cool it down to zero degrees Celsius. After the
beaker is cooled in the ice bath you should see a new solid formed. What
component is the solid that forms in the ice bath? Use the solubility properties
to determine what components are in the solution and what components are
in the solid at this time.
- Use vacuum filtration to separate the liquid from the solid. Before performing
vacuum filtration, make sure to think about what information you will need to
determine the mass of the solid and what you will use to wash the solid (either
boiling water or ice water).
- We now have two solids and one liquid. The solid on the filter paper can be
dried by continually pulling the vacuum. The solid in the beaker can be dried
by gently heating over a flame. The component that is still dissolved in water
can be isolated by transferring to a beaker and gently heating to remove the
water.
- When heating to remove the water, use “boiling stones,” so the solution does
not splatter. Add a few boiling stones to the solution. Think about whether you
will need to know the mass of these stones to determine the mass of the last
component.
Safety Considerations
Practice appropriate fire safety protocols for using Bunsen burners and working
with hot glassware. Examine SDS sheets for NaCl, SiO2, and benzoic acid
(C6H5COOH) to note special safety considerations for working with these
materials.
Waste Disposal
Dispose of solid waste in the appropriately labeled solid waste container. Dispose
liquid waste in the appropriately labeled liquid waste container.
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