Illustrated Guide to Home Chemistry Experiments

Chapter 6 Laboratory: Separating Mixtures 95

FIGURE 6-1: The filter paper captures the sand, allowing the

sucrose solution to pass into the receiving beaker

POCEDURER
CUTIOA nS

Chemicals Used In This Book ..........................................................................................................

are not hazardous, it is a matter of good laboratory

practice to wear splash goggles, gloves, and protective

clothing at all times. Be careful when heating the mixture

with the hotplate.

1.f you have not already done so, put on your splash I z

goggles, gloves, and protective clothing.

2. Weigh about 10.0 g of dry sand and about 10.0 g of
   sucrose and add both of them to a beaker. Record the
   masses on lines A and B of Table 6-1.


3. Stir the mixture or swirl the beaker until the sucrose
   and sand are thoroughly mixed.


4. Add about 25 mL of water to the beaker, and stir
   thoroughly to dissolve the sucrose.


5. Weigh a piece of filter paper and record the mass in
   Table 6-1.


6. Weigh the second beaker and record the mass in
   Table 6-1.


7. Set up your filter funnel over the second beaker, using
   the filter paper you weighed in the preceding step.


8. Swirl the contents of the first beaker to keep as much
   sand as possible suspended in the liquid, and pour the
   liquid through the filter funnel.


9. Use the wash bottle to rinse the beaker with a few
   mL of water and pour that water with any remaining
   sand through the filter funnel, collecting the filtrate
   (the liquid that passes through the filter paper; the
   solid remaining in the filter paper is called the filtrand)
   in a second beaker. Repeat if necessary until all of the
   sand has been transferred from the first beaker to the
   filter funnel.


10. Remove the filter paper from the funnel, being careful
    not to lose any of the sand. Place the filter paper on a
    watch glass, as shown in Figure 6-1, and heat it gently
    under a heat lamp or in a microwave or conventional
    oven until all moisture is driven off.


11. Weigh the filter paper and record the mass of the
    filter paper plus sand in Table 6-1. Calculate the mass
    of the sand.


12. Place the second beaker on the hot plate and bring
    it to a gentle boil. Continue boiling the solution until
    nearly all of the water has been vaporized. As the
    volume of the solution is reduced, the sugar begins to
    crystallize. Use the stirring rod to break up any large
    masses of crystals as they form. Reduce heat and
    continue heating gently until the sucrose remaining in
    the beaker appears dry. Be careful not to overheat the
    sucrose and char it.


13. After allowing it to cool completely, weigh the second
    beaker and record the mass of the beaker plus sucrose
    in Table 6-1. Calculate the mass of the sucrose.

dISpoSAL: All of the waste material from this

laboratory can be disposed of with household waste.

dAUL. Rp joNES CommENTS:

Make observations of the physical appearance of the sand

and sugar. Does it change as you go through the process?

This is a good rule of thumb to consider during any

physical or chemical manipulation.