Homemade Perfume

Besides enhancing the flavors of foods, chemistry can please our sense of smell, too. For thousands of years, people have collected the aromatic oils of plants and seeds in order to make sweet-smelling waters and perfumes. But they had to squeeze a great numbers of to get just a few drops of oil, and scent of the oil did not last very long.

Perfume making is probably one of the oldest forms of chemistry. Perfume makers soon realized that, by adding other ingredients to a plant's essential oils, not only could less oil be used, but the essential oil's scent would last longer.



You will need:

* 7 small jars or vials with lids
* Rubbing alcohol
* Popsicle stick
* Cotton swab
* Tweezers
* Paper towel
* 1/8 cup sample of each : fragrant rose petals, gardenia blossoms, orange-tree (or lemon-tree) leaves, eucalyptus leaves, pine needles, mint leaves, and whole cloves
* Tape or marking pen for labeling


Procedure

1. Press as many plant and flower samples into 1/8 cup (30 ml) as you can. Place each sample in its own jar.
2. Except for the cloves, crush the samples as finely as you can with the Popsicle stick.
3. Add 2 teaspoons (10 ml) of rubbing alcohol and continue crushing.
4. Add about 10 cloves to one of the jars and then add alcohol.
5. Puts lids on all the jars, and allow them to sit on a warm place for about a week.
6. After a week, open one of the jars and dip in the cotton swab. Lift the swab towards your face, and fan the air around the moist tip so that the odor reaches your nose.
7. Dab the moist tip against the back of your wrist, then allow the spot to dry. Smell it.
8. Use the tweezers to remove a sample of the plant material, and let it dry on the paper towel. Smell it.

Result

The moist swab had a strong alcohol scent mixed with the plant scent. After you allowed the liquid to dry on your skin, your skin had only the plant scent and no alcohol odor. The sample of dried plant has little or no scent.


Explanation

Alcohol dissolves the aromatic oils in plants so that the plant's oil are removed from the plant tissue, suspended in the alcohol, and preserved. Alcohol also evaporates very quickly when exposed to air. When you placed a sample of homemade perfume on your wrist and exposed it to the air, the alcohol dried quickly, leaving behind only the aromatic oil.


Display Tip

Document each stages of your perfume-making procedure with photograph. Place the actual jars of perfume on your display table, along with some clean cotton swabs so that your perfumes may be sampled. You can also dab a small amount of perfume on separate index cards and label them. Place a sample or picture of each type of plant you've used to create your perfumes.

Did You Know?

About hundred years ago, perfume manufacturers used a secret ingredients as a fixative to keep the scent from evaporating too quickly. The ingredient, ambergris, is a waxy liquid that coats the stomachs of sperm whales and protects the whales fro the sharp bones of cuttlefish. Ambergris has the strange property of turning into a solid as soon as it is removed from the whale and exposed to air, and early photographs of whale hunters show them covered with icicles of ambergris as they packed the stuff into pails for transporting. Luckily, no one uses ambergris anymore due to the chemical substitutes, and the needless killing of whales has almost stopped.

Source : Science Fair Projects by Glen Vecchione

Electroscope

You will need :

Small glass jar
Wire coat hanger
Aluminum foil
Cardboard
Strip of silver Mylar from helium balloon or wrapping paper
Plastic comb
Balloon
Pencil
Cellophane
Rubber cement
Electrical tape
Wire clippers
Pliers


An electroscope is a simple device that measures static electricity, or the freely flowing electrical charges of the atmosphere. Static electricity is caused by friction, or something rubbing against something else. This electricity-producing friction can be as harmless as a comb rubbing against hair or powerful as ice crystals rubbing against each other in a thundercloud.


Procedure :

1. Use the wire clippers to cut off a straight piece of wire from the hanger. Use the pliers to bend a section at one end into L shape.
2. Turn the jar upside down onto the cardboard, and trace a circle around the opening.
3. Cut out the circle and punch a small hole in its center with a pencil.
4. Carefully push the wire through the hole about 1 inch (2.5 cm), straight end first.
5. With as little cellophane tape as possible, attach the middle of the Mylar strip to be bent end of the wire so that the strip hangs down in two equal halves.
6. Rubber cement the cardboard circle to the top of the jar, with the bent end of the wire holding the Mylar strip pointing down.
7. Place electrical tape around the edges where the circle touches the rim of the jar, and place a thin band of cement around the wire where it punches through the cardboard.
8. After the rubber cement dries, crumple the aluminum foil into a tight ball, and carefully push it onto the top of the wire.
9. Rub the plastic comb or balloon against your hair or clothing (wool works best), and hold either one close to the aluminum foil ball.


Result :

If the air is dry enough, the ends of the Mylar strip fly apart when comb or balloon touches the ball.


Explanation :

An electroscope shows the attraction and repulsion of electrical charges. In all electrical activity, like charges repel and opposite charges attract. When you rub the comb, friction causes a positive charge to build up in the plastic. When you hold the positively charged comb near the aluminum foil ball, the comb attracts negative charges which move up through the wire so that only positive charges remain in the Mylar strip. Since both ends of the strip now have the sama charge, the ends of the strip flay apart.


Display Tip :

Display your electroscope along with an assortment of objects for creating static charges.

Source : Science Fair Projects by Glen Vecchione

Energy Conservation

The change in the kinetic energy of an object is equal to the net work done on the object

Work Energy Principle

In order to accomplish work on an object there must be a force exerted on the object and it must move in the direction of the force.

This fact is referred to as the Work-Energy Principle and is often a very useful tool in mechanics problem solving. It is derivable from conservation of energy and the application of the relationships for and energy, so it is not independent of the conservation laws. It is in fact a specific application of conservation of energy. However, there are so many mechanical problems which are solved efficiently by applying this principle that it merits separate attention as a working principle. For a straight-line collision, the net work done is equal to the average force of impact times the distance traveled during the impact.

Average impact force x distance traveled = change in kinetic energy

If a moving object is stopped by a collision, extending the stopping distance will reduce the average impact force.

Example of Force on Car

Source : http://hyperphysics.phy-astr.gsu.edu