Problem: In each of the following situations, what type of filtration device would you use?
A. Remove powdered decolorizing charcoal from 20mL of solution?
My answer: Filter Aid or Celite (diatomaceous earth)
B. Collect crystals obtained from crystallizing a substance from about 1 mL of solution.
Filter-tip pipette or Craig tube
C. Remove a very small amount of dirt from 1 mL of liquid?
Filter-tip pipette
D. Isolate 2.0 g of crystals from about 50 mL of solution after performing a crystallization?
Buchner funnel
E. Remove dissolved colored impurities from about 3 mL of solution?
Decoloring charcoal
F. Remove solid impurities from 5 mL of liquid at room temperature?
Filter paper
Problem: In each of the following situations, what type of filtration device would you use?
A. Remove powdered decolorizing charcoal from 20mL of solution?
My answer: Filter Aid or Celite (diatomaceous earth)
Your answer may be perfectly ok but I always worry about contaiminating the material with the "other" solid; i.e., in this case whatever filter aid you are using (mascerated paper et al and celite). Would just plain filter paper work as well?
B. Collect crystals obtained from crystallizing a substance from about 1 mL of solution.
Filter-tip pipette or Craig tube
I have had no experience with a filter tip pipette or a Craig tube but I can imaging what they are. From such a small volume you could almost decant the liquid and allow the crystals to dry.
C. Remove a very small amount of dirt from 1 mL of liquid?
Filter-tip pipette
Ok.
D. Isolate 2.0 g of crystals from about 50 mL of solution after performing a crystallization?
Buchner funnel
It would need to be a SMALL Buchner funnel. And 2 g of crystals can get lost on a large sheet of filter paper. Using a regular piece of filter paper and funnel would concentrate the 2 g in the center of the cone. The filter-tip pipette might work ok here too. Most of these answers are personal preferances, of course, but I would not go with a Buchner, even a small one.
E. Remove dissolved colored impurities from about 3 mL of solution?
Decoloring charcoal
This would probably work but you then must address the problem of getting rid of the charcoal. That becomes a repeat of one of the above questions.
F. Remove solid impurities from 5 mL of liquid at room temperature?
Filter paper
good, but this answer doesn't imply the others are not. I was just raising questions about some of them.
1 answer