Question

EXPLAIN WHAT IS SUBLIMATION AND ALSO GIVE AN EXAMPLE OF A SUBLIMATION EXPERIMENT...

Answer 1

The Process by which a component of solid/gaseous state directly converted into solid/gaseous state is known as Sublimation
Materials Needed:

1. Toilet bowl freshener.
2. Moth balls.
3. Two 100 mL beakers.
4. Two 150 mL beakers.
5. Clear, shallow dish or pan.
6. Ice.
7. Thermometer.

Optional Materials:

1. Iodine - dangerous (must be cooled and concealed)
2. Solid air freshener
3. Hot plate

Procedure:

1. Place a few small lumps of toilet bowl freshener in the bottom of the 150 mL
beaker.
2. Place a few moth balls in the bottom of the second 150 mL beaker.
3. Put the 100 mL beakers inside of the 150 mL beakers. They should fit nicely
inside of each other. However, the smaller beakers should not touch the
bottom of the larger ones.
4. Use a fume hood.
5. Fill the small beakers three-fourths full with ice. Be sure that no ice
gets into the larger beakers.
6. Fill the shallow dish or pan about one-third full with hot water (one or
two dishes may be used).
7. It might prove better to use the hot plate to heat the water and then
place the apparatus in the water bath for faster results.
8. Measure the temperature of the water bath and adjust it by adding cold
water until the temperature of the water bath is about 60 degrees C.
(You may experiment with a water bath temperature from 50-70 degrees C).
9. Place the sublimation apparatus in the shallow dish.
10. Observe what happens to the toilet bowl freshener and the moth balls
(solids).


Reaction:

The heat from the water bath causes the solids to vaporize (sublime). The cold,
smaller beakers cause the vaporized solids to condense and re-form solids
back to their original form (crystals).