8th Grade Science – Professor Shai

Filtration Lab

Section 5.4 – Page 97

 

Introduction

Filtration is a way to separate solids by using the characteristic property of their solubility.  Using an appropriate solvent, filtration allows you to separate soluble solids from insoluble solids.   The technique is simple.  You mix the solids into the solvent and shake like mad until the soluble solid is dissolved.  Then you filter the solution through filter paper and extract the insoluble solid.  The dissolved solid goes right through the filter paper with the liquid.

Goals

To separate a mixture of two solids using filtration.

Method

1.  Put 1.5 grams of a solid mixture I will give you into a test tube with 5 cc's of water. 
2. Stopper the tube and shake like mad until every bit of solid that can dissolve actually dissolves.  This should take about 3 minutes.
3. Filter the solution as shown in figure 5.6 on page 98.
4. Pour an extra 10 cc's of water into the funnel to wash off the filtered solid, and let the water drain through.
5. Then take all the filtrate (the liquid that went through the filter), place it in an evaporating dish and boil it until all the water is gone. 
6.  You should have the insoluble solid in the filter paper, and the soluble solid is now in the evaporating dish.


Conclusion

You can separate soluble and insoluble solids using a filter.


Book Problems

Do problems 4-5, on page 96,  and problems 6-8 on pages 98-99.  Ask me for help if you are not sure how to do them.