The
Science Notebook
Lionel Chem-Lab
- Chapter 12
NOTE: This book was published in 1942 as a manual to
accompany several Lionel Chemistry sets of the time. While
some of the experiments and activities here may be safely
done as written, a number of them use chemicals and methods no
longer considered safe. In addition, much of the
information contained in this book about chemistry and other
subjects is outdated and some of it is inaccurate.
Therefore, this book is probably best appreciated for its
historical value rather than as a source for current information
and good experiments. If you try
anything here, please understand that you do so at your
own risk. See our Terms of Use.
Pages 152 - 158
CHAPTER XII
CALCIUM, STRONTIUM AND BARIUM
Of the three metals, calcium, strontium
and barium, calcium is
the most important and we shall, therefore, devote most of the
space in this chapter to calcium and its compounds. Barium and
strontium resemble calcium closely but are more rare and more
difficult to prepare. For all three elements, the compounds are of
greater commercial importance than the pure metals.
Strontium compounds burn with a red flame while
barium burns with a green flame, and they are frequently used in
fireworks to produce colorful effects.
Calcium, on the other hand, has a number of
compounds of great commercial importance. Some of these well-known
substances are limestone, marble, lime, cement, plaster, mortar,
window glass and bones, all of these consisting principally of
calcium in one form or another.
A certain amount of calcium is necessary to the
body. To keep ourselves in good physical condition, particularly
our bones and our teeth, foods containing calcium, such as milk,
are necessary to our diet.
CALCIUM
Calcium occurs in great abundance in the earth
and ranks next to aluminum and iron in its widespread prevalence.
It is too active to occur in a free state, but its salts, calcium
carbonate, calcium sulfate, calcium phosphate and calcium fluoride
are present everywhere. When combined with oxygen, calcium oxide is formed;
combined with water it forms calcium
hydroxide.
Calcium carbonate occurs in nature as marble,
limestone and chalk which are nearly pure carbonate. Marble and
limestone are both important building materials while the glass,
cement and lime industries use limestone. Calcium carbonate is
sometimes used to neutralize acid soil. In finely powdered form,
this carbonate is one of the principal ingredients of tooth powder
and tooth paste.
EXPERIMENT No. 330 The Decomposition Of Calcium
Carbonate
(CL-77)
APPARATUS:
Marble chips, charcoal, alcohol lamp and blowpipe.
152
LIONEL
CHEM-LAB 153
PROCEDURE:
Place a few marble chips on the charcoal block. Light the alcohol
lamp and`direct the flame at the marble chips by means of the
blowpipe. Heat for several minutes until red hot. Cool and examine.
SUMMARY:
Marble chips contain calcium carbonate, which upon being heated,
decompose forming carbon dioxide gas and calcium oxide.
EXPERIMENT No. 331 Identifying Calcium
(CL-66, CL-77)
APPARATUS:
Nichrome wire, calcium chloride and alcohol lamp.
PROCEDURE:
Place a measure of calcium chloride on a hard surface and crush it
into a powder. Dip the nichrome wire into water and then into the
powder. Place the wire in the flame of the alcohol lamp and note the
reddish-yellow flame.
EXPERIMENT No. 332 Preparation Of Calcium Sulfide
(CL-77)
APPARATUS:
Calcium sulfate, powdered charcoal, test tube, alcohol lamp, sodium
bisulfate.
PROCEDURE:
Mix two measures of calcium sulfate and one measure of powdered
charcoal thoroughly on a sheet of paper. Transfer to a test tube and
heat for five minutes. Note how its water of crystallization is
driven off. Heat the mixture red hot for a few minutes and then
allow to cool. Put one measure of sodium bisulfate and a little
water into the test tube. Carefully smell the gas which is
liberated.
SUMMARY:
When calcium sulfate is thoroughly heated, the carbon unites with
oxygen to form carbon dioxide gas. The residue is calcium sulfide.
By adding sodium bisulfate, you have reproduced calcium sulfate and
also have made hydrogen sulfide which gives the strong odor.
THE LIMESTONE CAVERNS
In certain areas in this country, such as in
Virginia, Kentucky, and New Mexico, there are large underground
deposits of limestone. Due to the action of water containing
carbon dioxide in solution, extensive caves and caverns have been
formed. Throughout these caves, projections, similar in appearance
to icicles, have developed after thousands of years of chemical
action. These "icicles" are called stalactites and stalagmites. Stalactites hang downward from the
roof of the cave while the stalagmites project upward from the
floor.
EXPERIMENT No. 333 Limestone Ice
(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)
154 CALCIUM
These
stalactites and stalagmites in the Endless Caverns of New
Market, Va. were formed by the action of water and limestone
over a period of many thousands of years.
LIONEL
CHEM-LAB 155
APPARATUS:
Calcium oxide, small glass.
PROCEDURE:
Prepare some limewater by stirring three measures of calcium oxide
in a glass half full of water. Allow the precipitate to settle at
the bottom of the glass and pour off the clear liquid into a clean
glass. Allow the limewater to stand over night. Note the crusty
formation which appears.
SUMMARY:
The formation of a crust is due to the presence of carbon dioxide in
the air. The lime absorbs the carbon dioxide to form calcium
carbonate (the crust).
CALCIUM OXIDE
Calcium oxide, known as quicklime, is prepared
in a vertical lime kiln by heating crushed limestone. Quicklime is
a white solid which combines readily with water to form calcium
hydroxide, or slaked lime. The reaction takes place with much
bubbling and formation of heat.
EXPERIMENT No. 334 Preparing Quicklime
(CL-77)
APPARATUS:
Marble chips, alcohol lamp, blowpipe and charcoal block.
PROCEDURE:
Embed some marble chips in the charcoal block. Light the alcohol
lamp and direct the flame at the marble chips by means of the blow
pipe. Heat for a few minutes until the chips
become red hot. Allow to cool and note how the mass has changed to a
powder.
SUMMARY:
The marble chips contain calcium carbonate which upon being heated
release carbon dioxide and form lime or calcium oxide.
EXPERIMENT No. 335 Slaked Lime
(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)
APPARATUS:
Calcium oxide and heating spoon.
PROCEDURE:
Place two or three measures of calcium oxide in the heating spoon.
Add a few drops of water and try to slake the lime.
SUMMARY:
Note that the finished product is dry and resembles the original
lime.
EXPERIMENT No.
336 Calcium Hydroxide
(CL-33, CL-44, CL-55, CL-66, CL-77)
APPARATUS:
Calcium chloride, sodium carbonate, calcium oxide, test tube,
alcohol lamp or candle.
PROCEDURE:
Prepare some sodium hydroxide as explained in Ex-
156 CALCIUM
periment No. 344. Place two measures of calcium chloride in another
test tube half full of water and shake to dissolve. Pour into this a
few drops of the sodium hydroxide solution and note the white
precipitate. The white precipitate is calcium hydroxide or slaked
lime.
CALCIUM HYDROXIDE
We have already explained how calcium
hydroxide is formed. A dry white powder which has strong alkaline
properties, it can be produced cheaply and thus has many
industrial uses including softening water, removing hair from
hides, and. the manufacture of glass, mortar and plaster. When
calcium hydroxide is prepared with water in a saturated solution,
it is known as limewater
and is of great value in the laboratory and as a medicine.
Mortar,
prepared by mixing freshly slaked lime with sand and water, was
formerly used in the construction of buildings to hold bricks and
stones together, but has now been superseded by cement mortar.
California
Division of Mines - A view of a typical cement plant where
cement is made by heating a mixture of limestone and clay and
then grinding into a fine powder.
EXPERIMENT N0. 337 Preparation Of Mortar
(CL-66, CL-77)
APPARATUS:
Calcium hydroxide, sand, stirring rod, tin plate, mortar and pestle.
LIONEL
CHEM-LAB 157
PROCEDURE:
Place five measures of calcium hydroxide and three measures of sand
in the mortar and mix thoroughly. Add some water to the mixture and
continue stirring until a paste is formed. Spread this paste on the
tin plate and set aside for a few days. Examine occasionally to see
if the mortar hardens.
SUMMARY:
When calcium hydroxide, sand, and water are m1xed together, mortar
is formed. It hardens because calcium hydroxide combines with the
carbon dioxide in the air to form a solid carbonate.
Gypsum,
or calcium sulfate, is used as a fertilizer and in the manufacture
of cement. Plaster of Paris,
a form of gypsum, when mixed with water, sets or hardens to a hard
crystalline mass. It is used as a molding medium by designers,
sculptors and dentists.
EXPERIMENT No. 338 Plaster Of Paris
(CL-77)
APPARATUS:
Calcium sulfate, alcohol lamp, mortar and pestle, test tube.
PROCEDURE:
Heat a test tube containing ten measures of calcium sulfate for
about ten minutes to drive off the water of crystallization. Cool
the test tube and place the contents in the mortar. Grind this and
examine the fine white powder which is Plaster of Paris.
EXPERIMENT No. 339 How To Make Portland Cement
(CL-66, CL-77)
APPARATUS:
Calcium carbonate, mortar and pestle, blowpipe, clay, candle or
alcohol lamp.
PROCEDURE:
Put seven measures of calcium carbonate in the mortar and mix
thoroughly with two measures of common clay. Place the mixture in
the heating spoon and heat, directing the flame with the blowpipe.
Continue heating until the mass becomes white hot. Crush this
material and add a little water. Note how it hardens within a few
days.
SUMMARY:
Cement has been used for centuries as a binding material in
construction work. Today Portland cement is the type most commonly
used. It is made by heating a mixture of clay and calcium carbonate
to a very high degree and then crushing it to a fine powder. This
type of cement takes a number of days to harden completely.
Calcium
chloride has a peculiar tendency to absorb moisture
rapidly and for this reason you have probably seen it scattered
along dirt roads and tennis courts as a white powder used to "lay"
the dust.
EXPERIMENT No. 340 How To Make Anhydrous Calcium
Chloride
(CL-33, CL-44, CL-55, CL-66, CL-77)
APPARATUS:
Calcium chloride, alcohol lamp and test tube.
158 CALCIUM
PROCEDURE:
Heat five measures of calcium chloride in a test tube for five
minutes. Note how the compound loses its water of hydration and
puffs out. Add a few drops of water when the calcium chloride
appears to be very dry. Note how quickly it absorbs the water.
SUMMARY:
When calcium chloride is heated, it loses its water of hydration and
becomes anhydrous (without water).
When chlorine is passed over freshly slaked
lime, bleaching powder
(calcium hypochlorite) is formed. This is a very unstable white
powder combining readily with acids to form chlorine. It is thus
used in the preparation of chlorine for bleaching purposes and
disinfectants.
STRONTIUM
EXPERIMENT No. 341 How To Make Strontium Chromate
(CL-77)
APPARATUS:
Sodium chromate, strontium nitrate, test tubes.
PROCEDURE:
Dissolve two measures of strontium nitrate in a test tube half
filled with water. Dissolve three measures of sodium chromate in
an-other test tube one quarter filled with water. Pour one solution
into the other. A yellow precipitate of strontium chromate is
formed.
EXPERIMENT No. 342 Precipitating Strontium
Carbonate
(CL-33, CL-44, CL-55, CL-66, CL-77)
APPARATUS:
Strontium chloride, sodium carbonate and test tubes.
PROCEDURE:
Dissolve two measures of strontium chloride in a test tube one half
full of water. Dissolve one measure of sodium carbonate in another
test tube one quarter full of water. Pour one solution into the
other. A white precipitate of strontium carbonate is formed.
EXPERIMENT No. 343 Precipitating Strontium
Sulfate
(CL-77)
APPARATUS:
Calcium sulfate, strontium nitrate and test tubes.
PROCEDURE:
Dissolve four measures of calcium sulfate in a test tube one quarter
full of water. Place one measure of strontium nitrate in another
test tube containing the same amount of water. Pour one solution
into the other. Warm gently to hasten the precipitate of strontium
sulfate.
"The Science Notebook"
Copyright 2008-2018 - Norman Young
