3. Shown below are some of the basic items used in a
chemistry lab. Identify each one.
a
CHEMISTRY
b
WARNING: Always follow instructions when using chemicals. Experimenting on your own may be hazardous.
c
d
1. Be able to repeat the following safety rules to your
counselor in your own words.
• Do not mix chemicals in amounts greater than
the experiment states.
• Clean up spilled chemicals immediately.
• Get rid of chemicals as stated in the instructions.
• Keep chemicals out of reach of younger children.
• Contact an adult immediately if an accident
­occurs.
• Wear an apron or smock.
• Do experiments in a place that is well ventilated.
• Never place fingers in eyes or mouth when working with chemicals.
e
a. ____________________________________
b. ____________________________________
c. ____________________________________
d. ____________________________________
e. ____________________________________
Date Completed:Passed By:
You must also demonstrate that you know these
rules when doing your experiments.
Date Completed:Passed By:
2. Write the meaning of the following terms.
Element_________________________________
________________________________________
Compound_______________________________
________________________________________
Solution_________________________________
________________________________________
Suspension_______________________________
________________________________________
Mixture__________________________________
________________________________________
Date Completed:Passed By:
EXPLORING: SCIENCE: CHEMISTRY
Perform at least four of the following chemistry experiments for the Cadets in your cadre or club. Choose only
one of your experiments from 1 or 2.
1. Invisible Writing
You need a sheet of white paper; a test tube; a soft
lead pencil; a watercolor brush; and salt (sodium
chloride).
Fill the test tube ¼ full of water and then add
two tablespoons (60 gm) of salt. Shake the tube so
the salt dissolves. Dip the brush into the solution.
Print the name of your counselor on the paper with
the brush. Let the paper dry. Then rub the pencil
lead across the letters lightly. His name will appear
in black.
The salt crystals that have dried on your paper
from your writing rub off more carbon from your
pencil lead than the smooth paper does, making the
name darker.
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2. Invisible Ink
You will need a cotton swab or paint brush, ordinary
white paper, lemon juice, iodine, water, and a tray to
hold the water.
Using a cotton swab or a paint brush, write on
an ordinary piece of white paper with lemon juice.
Let your writing dry.
Mix two droppers of iodine with two cups of
water in a tray. Dip your paper into the tray. Your
paper will turn blue and your writing will appear.
The iodine molecules get trapped into the glucose molecules that form your paper, forming a blue
complex. The vitamin C from the lemon juice reacts
with the iodine and forms a colorless compound.
Adding water to cobalt chloride changes the
mixture to a hydrate, which becomes off-white or
pink in color.
3. Red, White, and Blue
You will need ExLax (capsules or tablets; or a storebrand equivalent), high strength rubbing alcohol,
epsom salt, root killer (containing copper sulfate),
and ammonia. You will also need three clear plastic
or glass cups.
Prepare a mixture of crushed ExLax and a small
quantity of rubbing alcohol. Place one teaspoon of
this solution (phenolphthalein) into the first cup.
In the second cup, add a few sprinkles of epsom
salt.
In a third cup, add a few sprinkles of root killer
from your hardware/gardening store.
Then add some ammonia to each cup. Phenolphthalein (cup #1) turns bright magenta in the ammonia base. The magnesium from the epsom salts
react with the hydroxide in the ammonia, creating
magnesium hydroxide which is not very water soluble. This gives the white appearance to the solution
in cup #2. The third cup involves a reaction between
copper from the root killer and the ammonia, forming
a deep blue water-soluble compound. The copper in
the root killer has a blue color even when mixed in
water, but not as dark a color as when mixed in the
ammonia.
6. Relighting Straw
You need matches; a piece of straw (from a broom)
or wooden toothpicks; sodium hypochlorite (chlorine
bleach); hydrogen peroxide; a small glass jar; and a
piece of cardboard large enough to cover the top of
the jar.
Place 2 tablespoons (60 ml) of bleach into your
jar. Add 1 teaspoon of hydrogen peroxide to the
bleach; it will bubble. Do this three or four times. On
the last time, cover the jar immediately. Light your
toothpick or broom straw and let it burn a bit. Blow
it out (the end should continue to glow). Quickly
move the cover off the jar and insert the glowing
toothpick/straw into the jar. Poof! The toothpick/
straw will burst into flames again. You can repeat
this process several times.
Bleach speeds the decomposition of the hydrogen peroxide back to pure oxygen and water. Your
toothpick/straw will burn much quicker in the pure
oxygen.
4.Weatherman
You need a saucer; a test tube; white crepe paper;
cobalt chloride.
Fill the test tube ½ full of water. Add 1½ teaspoons
(15 gm) of cobalt chloride. Cut four strips of crepe
paper about ½" (1 cm) wide and 4" (10 cm) long.
Place them on top of each other and then roll them
up. Place the roll in the saucer and pour the solution
in the test tube over it. Then unroll the four strips
and dry them indoors. When they are completely
dry, fasten them somewhere outside where they will
be protected from rain or snow. Bring them to your
next Cadet meeting. If the weather is dry, they will
be blue. If the weather is wet, they will be pink.
2
5. Relighting Candle
You need a candle in a small candle holder; matches.
Light the candle and place it where everyone
can see it clearly. Blow it out and then immediately
light another match. Hold it about 3" (7 cm) above
the candle wick in the column of smoke. The flame
will jump down and light the wick again. You can do
this one over and over.
The vapors and particles in the smoke will still
burn; these vapors and particles in turn conduct the
flame down and relight the wick.
7. Floating Seeds
You need a tall glass; an unopened bottle of ginger
ale; a seed from a grape or apple.
Fill the glass with ginger ale. Drop in the seed.
Tell everyone that you know the seed will rise and
fall. The bubbles will burst when the seed reaches
the top. Then the seed begins to sink again. As soon
as it reaches the top, it again sinks back down. You
can repeat this over and over.
The dissolved carbon dioxide gas in carbonated
water collects on the seed. When enough gas has
collected on the seed, the bouyancy and density of
the seed changes and it floats to the surface. The
gas is released at the surface, and the seed drops
and the process begins again.
8. Super Strong String
You need a cup; a small hairpin made into a ring;
a wire coat hanger; a piece of heavy cotton string
about 12" (30 cm) long; salt (sodium chloride).
Before your Cadet meeting, fill the cup ½ full of
water and stir in your salt until no more will dissolve.
Soak the string in this solution for about half a day.
Then lift the string out carefully and let it dry (don’t
put it near direct heat). At the meeting, tie one end
of the string to the ring and the other end to the
coat hanger. Place the hanger up high and away
from anything that will catch fire (see your counselor
about this). Light the string with a match just above
the ring. Watch it burn. The thread will burn up, but
the ring will hang suspended by the ashes.
Your string is very saturated with salt, which
does not burn. So, after your string burns, the salt
crystals are still there, coated in carbon from burning
the string, and suspending your ring.
9. Active Volcano
You need a sheet of paper; pliers; an alcohol lamp
from a chemistry set; a lid cut from a large tin can;
cobalt chloride; sugar; sulfur.
Place 2 teaspoons (20 gm) of sugar on the piece
of paper. Add 1½ teaspoons (15 gm) of cobalt chloride
and 1 teaspoon (10 gm) of sulfur. Mix them together
well and then place the mixture in the middle of the
tin cover so that it looks like an upside down cone
(your volcano). Using the pliers as a handle, hold the
tin over the flame on the alcohol lamp. The pile of
chemicals will puff up and get larger and larger.
As the chemicals are heated, gases are produced
that are larger in volume than the original chemicals.
Warning: there will be a strong odor when this experiment is performed!
10. Burning Metal
You need a candle; iron filings or powder.
Light the candle and sprinkle the bits of iron
(only a few at a time) down into the flame. They will
look like tiny stars as they burn. Who ever thought
iron would burn!
Heat moves the electrons in the iron to a higher
energy level. When they return to their normal energy
level, a spark is produced.
11. Solid or Liquid?
You need 5 tablespoons (75 mL) of cornstarch, 3
tablespoons (45 mL) of water, something to stir with,
and a shallow bowl.
Put the cornstarch in the bowl. Add the water
and stir. Squeeze the mixture for a little while. Then
release the pressure and feel it ooze.
When the mixture is pressed, it feels solid because the molecules line up. When you stop squeezing, the molecules relax and the suspension flows.
EXPLORING: SCIENCE: CHEMISTRY
12. Steel Wool Heat
You need a piece of steel wool, a jar, vinegar, and a
thermometer.
Place the thermometer in the jar, close the lid,
and record the temperature after five minutes. Remove the thermometer. Soak the steel wool in vinegar for one minute. Squeeze the vinegar out of the
steel wool and wrap the steel wool around the bulb
of your thermometer. Place the thermometer with the
steel wool wrapped on it back into the jar and close
the lid. After five minutes, check the temperature.
The vinegar removed the protective coating from
the steel wool, causing it to begin to rust (a slow
combination of iron and oxygen). When this happens,
heat energy is released, causing the temperature to
rise.
13. Ice Cream
You need one small zip-lock bag, one large zip-lock
bag, milk, sugar, vanilla flavoring, rock salt, ice, and
a thermometer.
In the small zip-lock bag, place 1 cup (240 mL)
milk, ½ cup (92.4 g) sugar, and ½ teaspoon (2.5 mL)
vanilla flavoring. Seal bag and mix well.
In the large zip-lock bag, place two cups of ice.
Find the temperature of the ice. Then add ½ cup
(200 g) rock salt to the ice. Place the sealed small
bag inside of the large bag and seal the large bag.
Hold the large bag by the top seal and gently rock it
from side to side; do not hold the bag in your hands.
After the contents of the small bag have hardened, open the large bag and measure the temperature of the larger bag. Eat the contents of the small
bag!
Adding salt to the water interfered with the orderly arrangement of the crystals. More heat must
be removed from the water (ice) for freezing to
continue — resulting in a lower freezing point.
EXPERIMENT LOG
Experiment
Date
Passed by
#1__________________ _________ ____________
#2_________________ _________ ____________
#3_________________ _________ ____________
#4_________________ _________ ____________
Badge Approved by:_________________________
Badge Completed on:_ _______________________
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