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  Lionel Chem-Lab - Chapter 2

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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  In addition, much of the information contained in this book about chemistry and other subjects is outdated and some of it is inaccurate.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 17 - 39

CHAPTER II

INTRODUCTION TO CHEMISTRY

Every one is acquainted with the most common and useful kinds of matter.  The water we drink, the food we eat, the clothes we wear, the air we breathe; in short, anything which has weight or occupies space can be referred to as matter.

Matter is composed of tiny particles called molecules which are the smallest integral parts of a substance.  A further subdividing of these molecules will cause the substance to lose its original properties.

DIVISION OF MATTER

Molecules cannot be divided mechanically.  There are more molecules in one drop of water than there are drops in the Pacific Ocean.  Take a match stick, for example, and break it in half.  Both pieces will have the identical properties of wood, each piece consisting of millions upon millions of molecules.  Break the matchstick again until the pieces are as small as you can get them and still each fragment will be composed of millions of molecules each one having the properties of the whole match stick.

To demonstrate further the division of matter, perform the following experiment:

EXPERIMENT No. 1 Division Of Matter

(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77) *

APPARATUS: Sodium chloride (table salt) and three small glasses.

PROCEDURE: Dissolve five measures of sodium chloride in a glass half filled with water.  Taste the solution.  Divide the sodium chloride solution equally among the three glasses.  Fill the these with water.  Taste all solutions again.

SUMMARY: Each solution has the salt taste and if the dilutions (or divisions) or continued until the last drop, even here will the salt be present.

LAW OF CONSERVATION OF MATTER

In addition to the above characteristics, matter is a substance which cannot be created or destroyed.  This is commonly known as the law of Con-

* The numbers beneath the title of each experiment indicate the Chem-Lab set with which the experiment can be performed.

17


18 INTRODUCTION TO CHEMISTRY

servation of Matter and explains that, although the matter may be broken up into small parts or transformed as a result of many chemical actions, the one property which can never be changed is its mass.  That is to say, if the weight of the materials used prior to the experiment is compared with the weights of the resulting products, they will be the same no matter how great the change may be.

EXPERIMENT No. 2 Law Of Conservation Of Matter

(CL-55, CL-66, CL-77)

APPARATUS: Piece of wood and Lionel balance.

PROCEDURE: Weigh piece of wood.  Burn wood to ashes.  Collect ashes and weigh them.

SUMMARY: The weight of the wood is less than it was before burning.  This apparent loss of weight, however, can be accounted for by the gas and smoke which escaped into the air as the properties of the wood changed while burning.  If the gas and smoke could have been weighed, they would account for the loss.

EXPERIMENT No. 3 Law Of Conservation Of Matter

(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Candle, two dry wide-mouthed bottles, calcium oxide, test tube.

PROCEDURE: Prepare limewater by dissolving four measures of calcium oxide in a test tube filled with water.  Cover and allow the undissolved particles to settle to the bottom of the tub.  Light candle.  Invert one bottle over the flame until flame goes out, cover and remove.  Pour clear limewater into the bottle and shake gently.  Add limewater to the other bottle and shake.

SUMMARY: The flame of a burning candle seems to vanish giving off heat and light while doing so.  However, what we do not see is the moisture being given off, part of which was collected on the cold inside walls of the first bottle.  As limewater is added to the first bottle, the clear liquid becomes cloudy.  This does not happen in the second bottle which proves that the candle is not destroyed but forms water and gas (carbon dioxide) as it burns causing the milky appearance of the limewater.

STATES OF MATTER

When ice melts, it becomes water and this same water eventually evaporates and becomes a gas.  Thus, water illustrates the three states in which matter exists - solid, liquid, and gas.  The states are dependent upon pressure and temperature.


LIONEL CHEM-LAB 19

Matter is constantly in motion.  This is evident from the fact that a person sitting in a room adjoining a kitchen where a gas jet is open will detect the odor.  Naturally, before one can smell the odor, it must be carried to the nostrils.  This carrying process illustrates matter in motion.

EXPERIMENT No. 4 Matter In Motion

(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Iodine crystals (obtainable at a drugstore), test tube and cork.

PROCEDURE: Place one measure of iodine crystals in a dry test tube.  Cork the test tube.  Apply heat slowly.

SUMMARY: As the iodine crystals began to evaporate, or volatilize, a beautiful violet colored gas forms and, in accordance with the theory of the movement of matter, diffuses throughout the tube.

EXPERIMENT No. 5 Matter In Motion

(CL-11, CL-22, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Ammonium chloride and a heating spoon.

PROCEDURE: Place four measures of ammonium chloride on the heating spoon.  Heat for a few minutes.  In a short time, the ammonia gas liberated by decomposition will be easily detected by its pungent odor.

Although it has been proved that molecular movement occurs in all three states of matter, the motion is not a visible one and can only be illustrated with gases and liquids.  The previous experiments illustrate this theory as applied to gases while the following experiment will demonstrate it in the case of liquids.

EXPERIMENT No. 6 Matter In Motion

(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

Repeat Experiment No. 1

SUMMARY: the taste of salt is in all three solutions proving that the molecules of the liquid have distributed the salt to all parts of the three glasses.

MOLECULAR THEORY

We have already mentioned that the three classes of matter are gases, liquids, and solids.  The distinguishing physical properties of air, water and stone are obvious, but only in recent years has science been able to actually describe these differences in a satisfactory way by the Molecular Theory.

In the previous paragraphs, we mentioned that all matter was composed


20 INTRODUCTION TO CHEMISTRY

of tiny particles called molecules which were the smallest indivisible parts into which a substance can be divided and still retain its original properties.  In simple language, this theory merely states that all matter has a granular structure, somewhat similar, on a small scale, to a heap of baseballs or a pile of sand.

Now the question arises as to the size of these tiny particles.  How large are they?  Could they be seen under a microscope?  Science states that if ten million molecules were placed in a row, there resulting length would only be about the thickness of a dime.  This gives you some idea of their minuteness.

Another interesting fact about molecules is that they are in constant motion and are striking and rebounding against each other in ceaseless and tireless activity, somewhat similar to the way particles of dust appear in a shaft of sunlight.  This leads up to the essential difference between gases, liquids, and solids which can be explained entirely by the movement and space occupied by the molecules.  Science has established that molecules of the same substance are always exactly alike but their positions will vary considerably in different states of matter.

For example, the difference between a gas and liquid is that in the liquid the molecules are closer together and their movements shorter.  In both substances, however, the molecules are in complete disorder and always occupy a different spot having no "home" or fixed place to return.  But in solids, particularly crystals, it appears that a molecule does not move out of its prearranged course.  If it did, the beautiful lines of a crystal, it's faces, would ultimately change their size and shape.

CHANGES IN MATTER

If you were able to project yourself into the world of a billion years ago to notice the plants, animals and rocks of that ancient time, and then come back to make a comparison with the matter of today, you would be forced to make one conclusion: great changes in the world have taken place.  These changes have been chemical and physical.  That is to say, the change may have been a reshaping of former substances or formation of entirely new substances.

PHYSICAL AND CHEMICAL CHANGES

If an iron bar is heated to a high temperature in a vacuum, it will become soft and melt, its color changing into a dull red and eventually to a bright white.  Interestingly enough, however, if the metal is allowed to cool, the original properties of the iron are restored.  The heating produced a change in physical properties but throughout the procedure the iron remained iron.  Thus it can be stated that a physical change does not affect the composition of matter.


LIONEL CHEM-LAB 21

Water freezes in cold weather to form ice which melts with a rise in temperature and returns to its original liquid state.  Many of the properties of water were altered when the water changed from liquid to solid, yet the substance is still water.

Other familiar types of physical changes are the melting of wax, the magnetizing of steel, dissolving of sugar, crushing of stone and glass, and the changing of water into steam.

Thus, any change in a substance whereby some of its properties are altered, but in which there is no change in the composition of the substance, is called a physical change.

Expose an iron bar to moist air.  In due time it will rust into the reddish-brown powder which differs from the iron in appearance.  This is no longer the simple substance of iron but a compound formed when the iron combined with the oxygen in the air.  Such a change is a chemical change and involves the transformation of matter into a substance or substances having entirely different properties.

Thus, we can say that a physical change is one which leaves a substance unaffected while a chemical change is one in which all the properties of the material are altered so that one or more new substances are produced.

COMBINATION OR DIRECT UNION

Chemical reactions have been classified into several types, the simplest form being combustion or direct union wherein two or more substances combine to form a more complex substance.

EXPERIMENT No.  7 Oxidation Of Iron By Heat

(CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Powdered iron filings, heating spoon, alcohol lamp or candle.

PROCEDURE: Place three measures of iron filings in the heating spoon.  Heat for a few minutes.  Cool and examine.

SUMMARY: The blue-black oxide formed by the direct union of iron with oxygen in the air is the new compound, iron oxide.

EXPERIMENT No. 8 Oxidation Of Sulfur

(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Sulfur, heating spoon, candle, or alcohol lamp.

PROCEDURE: Place four measures of sulfur in the heating spending.  Smell the sulfur.  Heat carefully until the sulfur begins to burn.  Smell the odor from the sulfur again, but this time very cautiously.


22 INTRODUCTION TO CHEMISTRY

SUMMARY: The sulfur did not give off any strong odor prior to heating.  With the application of heat, however, there was a direct union between the sulfur and oxygen in the air to form the new product, sulfur dioxide.  This compound is easily detectable because of its odor.

EXPERIMENT No. 9 Iron And Sulfur Chemically Combined

(CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Powdered iron, sulfur, test tube, candle or alcohol lamp.

PROCEDURE: Mix thoroughly on a piece of paper five measures each of iron and sulfur.  Transfer mixture to a test tube.  Heat for a few minutes.  Allow test tube to cool and examine contents.

SUMMARY: The black porous, and non magnetic compound is ferrous sulfide the properties of which are entirely different from those of iron and sulfur.  Since the iron and sulfur combined to form an entirely new substance, it can be said that a chemical combination has occurred.

EXPERIMENT No. 10 Zinc Combined With Sulfur

(CL-44, CL-55, CL-66, CL-77)

APPARATUS: Powdered zinc, sulfur, heating spoon, candle or alcohol lamp.

PROCEDURE: Mix one measure each of powdered zinc and sulfur on a piece of paper.  Place this mixture in the heating spoon and heat it cautiously taking care to keep your face away from the reaction.

SUMMARY: A flash reaction accompanies the chemical combination of zinc and sulfur which forms zinc sulfide, often called zinc-blende or blackjack by miners, and sphalerite by mineralogists.

EXPERIMENT No. 11 Carbon Combined With Oxygen

(CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Charcoal, heating spoon, candle or alcohol lamp.

PROCEDURE: Place three measures of charcoal in the heating spoon.  Heat until the charcoal appears to turn gray.

SUMMARY: When carbon or a substance containing carbon, such as charcoal, wood, or coal is heated, the element combines directly with the oxygen of the air to form carbon dioxide gas.

EXPERIMENT No. 12 Copper Combined with Oxygen

(CL-44, CL-55, CL-66, CL-77)

APPARATUS: Copper penny, test tube holder, alcohol lamp.

PROCEDURE: Using the test tube holder, hold the face of a bright penny directly over the oxidizing portion of the alcohol flame.  Remove

LIONEL CHEM-LAB 23

penny from the flame when scales began to form on the face.  After cooling, examine the scales.

SUMMARY: Heating copper in the presence of air causes the formation of copper oxide scales.

EXPERIMENT No. 13 Copper United With Sulfur

(CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Copper strip, sulfur, test tube, candle or alcohol lamp.

PROCEDURE: Make some copper filings by scraping the copper strip with a course file.  Mix three measures each of copper and sulfur on a piece of paper.  Heat the mixture in a test tube.  Cool and examine contents.

SUMMARY: Before heating, the sulfur and the copper filings were a simple mixture.  However, after heat has been applied, we obtain the black mass of copper sulfide, the properties of which bear no resemblance to those of the elements which it comprises.

EXPERIMENT No. 14 Magnesium Combined Directly With Oxygen

(CL-77)

APPARATUS: Powdered magnesium, heating spoon, candle or alcohol lamp.

PROCEDURE: Place one quarter measure (and no more) of powdered magnesium in the heating spoon.  Apply heat cautiously, keeping your face away from the reaction.

SUMMARY: Magnesium combines so readily with oxygen in the air that a brilliant flame accompanies the reaction.  The white power, magnesium oxide (commonly called magnesium) has properties altogether different from the properties of its constituents.  Thus we know that the combining of the elements has resulted in a chemical change.

DECOMPOSITION

Combination, you recall, was a chemical change which had to do with putting together substances to form a new one.  Now let us study a second type of chemical change, decomposition, which is a separation or breaking down of a complex substance into its constituent parts.  The two reactions are direct opposites.  They can easily be remembered by thinking of the first two letters of each word: co meaning together and de meaning apart.

An electric current passed through water is an example of decomposition.  In this case, the products are hydrogen and oxygen, the two constituent elements of water, and the process is called electrolysis which is explained to more clearly in our chapter on Water.


24 INTRODUCTION TO CHEMISTRY

EXPERIMENT No. 15 Decomposing Sugar

(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Sugar, dry test tube, candle or alcohol lamp.

PROCEDURE: Place five measures of granulated sugar in test tube.  Heat slowly keeping the tube away from your face.  Allow to cool.  Examine contents.

SUMMARY: Heat decomposes the sugar which takes the form of water and a black residue, mainly carbon, on the inner surface of the test tube.

EXPERIMENT No. 16 Decomposing Carbonate

(CL-77)

blowpipe and charcoal block

FIGURE 6

APPARATUS: Marble chip (calcium carbonate), blowpipe, charcoal block and alcohol lamp or candle.

PROCEDURE: Embed a small marble chip in the charcoal block.  Direct a flame at the chip by means of the blowpipe.  Heat for a few minutes until red hot.

SUMMARY: When heated the marble chip becomes whiter and when

LIONEL CHEM-LAB 25

the flame is taken away, the white product left is calcium oxide, often called lime. The gas given off in this reaction is carbon dioxide.

EXPERIMENT No. 17 Decomposing Sodium Thiosulphate

(CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Sodium thiosulfate, test tube, candle or alcohol lamp.

PROCEDURE: Place four measures of sodium thiosulfate in the test tube. Heat carefully for a few minutes. Test gas given off with sulfide (lead acetate) test paper. Allow to cool. Examine contents.

SUMMARY: By heating, sodium thiosulfate is decomposed into simple compounds and elements. The first noticeable variation is the formation of moisture on the inner walls of the test tube. This is the water of crystallization of sodium thiosulfate which is being given off. Moreover, the gas escaping from the mouth of the test tube is hydrogen sulfide, easily detectable by its rotten egg odor and the dark stain it forms on lead acetate test paper. As the heating continues, sulfur deposits itself near the mouth of the test tube. The other constituents which remain at the bottom of the test tube are the compounds sodium sulfide and sodium sulfate.

EXPERIMENT No. 18 A Decomposition After An Exchange

(CL-44, CL-55, CL-66, CL-77)

APPARATUS: Sodium carbonate, tartaric acid, two test tubes.

PROCEDURE: Dissolve two measures of sodium carbonate in a test tube one-quarter filled with water. Dissolve two measures of tartaric acid in a second test tube containing the same amount of water. Pour the contents of the second tube into the first. Note the bubbling at the surface of the liquid.

SUMMARY: Sodium carbonate reacts with tartaric acid to form sodium tartrate and carbonic acid. This acid, being unstable, decomposes into water and carbon dioxide gas. This gas causes the bubbling.

DOUBLE DECOMPOSITION

Still another type of chemical change is double decomposition in which two compounds interact to form two other compound substances. An interchange occurs, a re-pairing of chemicals much in the same fashion that two dancing couples change partners.

EXPERIMENT No. 19 Interchange Of Elements In Double Decomposition

(CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Strontium chloride, aluminum sulfate, two test tubes.

26 INTRODUCTION TO CHEMISTRY

PROCEDURE: Dissolve three measures of strontium chloride in a test tube half full of water. Using aluminum sulfate, repeat the procedure with the other test tube. Mix the two solutions.

SUMMARY: The elements of strontium and aluminum exchange places in the reaction and the new compounds are aluminum chloride, a white crystalline salt, and strontium sulfate, a heavy white precipitate which settles at the bottom of the test tube.

EXPERIMENT No. 20 Another Double Decomposition

(CL-55, CL-66, CL-77)

APPARATUS: Copper sulfate, sodium ferrocyanide, two test tubes.

PROCEDURE: Dissolve a small crystal of copper sulfate in a test tube half filled with water. Repeat the procedure in the other test tube with sodium ferrocyanide. Pour one solution into the other.

SUMMARY: The elements of copper and sodium interchange positions and the new products are sodium sulfate, a soluble salt, and copper ferrocyanide which is insoluble and settles at the bottom of the test tube as a reddish-brown precipitate.

EXPERIMENT No. 21 A Sulfate Reacts With Strontium Nitrate

(CL-66, CL-77)

APPARATUS: Aluminum sulfate, strontium nitrate and two test tubes.

PROCEDURE: Dissolve two measures of aluminum sulfate in a test tube one-quarter filled with water. Dissolve three measures of strontium nitrate in another test tube one-quarter filled with water. Pour this into the first solution.

SUMMARY: The aluminum and the strontium exchange places to form aluminum nitrate, which is soluble in water, and the white precipitate, strontium sulfate.

EXPERIMENT No. 22 A Sulfate Reacts With Calcium Oxide

(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Ferric ammonium sulfate, calcium oxide and test tube.

PROCEDURE: Dissolve one measure of ferric ammonium sulfate in a test tube half filled with water. Add one measure of calcium oxide and shake the tube well.

SUMMARY: Ferric ammonium sulfate reacts with calcium oxide to form calcium sulfate and the reddish-brown precipitate of ferric hydroxide.

DISPLACEMENT

The chemical change known as displacement, or simple replacement, merely means that one element in a compound is replaced by another free element.


LIONEL CHEM-LAB 27

EXPERIMENT N0. 23 Chlorine Displaces Iodine

(CL-55, CL-66, CL-77)

APPARATUS: Sodium bisulfate, calcium hypochlorite, sodium iodide solution, test tube.

PROCEDURE: Dissolve one measure of sodium bisulfate in a test tube half filled with water. Add a half measure of calcium hypochlorite. Shake well. Add two or three drops of sodium iodide solution.
Shake again and observe the reddish-brown color.

SUMMARY: Calcium hypochlorite reacts with sodium bisulfate forming chlorine gas which remains dissolved in the solution. When the sodium iodide is added, the chlorine takes the place of, or displaces, the iodine forming sodium chloride (common salt) and liberating iodine detectable by its brown color.

EXPERIMENT No. 24 Displacement Of Hydrogen By Zinc

(CL-44, CL-55, CL-66, CL-77)

APPARATUS: Zinc, hydrochloric acid, test tube.

PROCEDURE: Place a small piece of zinc in the test tube. Carefully add about one third of a test tube full of hydrochloric acid. Observe the rising of the hydrogen bubbles.

SUMMARY: Acids, such as hydrochloric, contain hydrogen in combination with other elements. Certain metals when brought into contact with these acids displace the hydrogen in them. The zinc unites with the chlorine of the hydrochloric acid to form zinc chloride and hydrogen, some of which adheres to the zinc strip, or rises in the form of bubbles to the surface.

EXPERIMENT No. 25 Zinc Displaces Copper From Solution

(CL-55, CL-66, CL-77)

APPARATUS: Copper sulfate, zinc, test tube.

PROCEDURE: Dissolve one small crystal of copper sulfate in a test tube one-third filled with water. Drop into this a small piece of zinc. Shake well and allow to stand for some time. Observe that the zinc strip begins to take on the appearance of copper and the blue color of the copper sulfate solution loses its intensity.

SUMMARY: The zinc displaces the copper from the copper sulfate solution to form the new compound, zinc sulfate, and the displaced copper deposits itself on the zinc.

EXPERIMENT No. 26 Iron Displaces Copper From Solution

(CL-55, CL-66, CL-77)

APPARATUS: Copper sulfate, test tube, powdered iron.

PROCEDURE: Dissolve one small crystal of copper sulfate in a test tube one-third filled with water. Add one measure of powdered iron to the blue copper sulfate solution. Shake well for a few minutes. Note

28 INTRODUCTION TO CHEMISTRY

that the iron filings take on a rusty reddish appearance and the blue solution becomes lighter.

SUMMARY: Iron, in the form of iron filings, displaced the copper from the copper sulfate solution and formed the compound known as iron sulfate. The copper which is set free in the metallic state deposits itself on the iron filings.

SUBSTANCES

The iron sash-weight of the window in your room, the iron chain which holds the weight, the iron water pipes in your cellar - forms so different to the manufacturers who made them, are alike to the chemist, for they all consist of the same substance - iron. A substance, then, is a specific kind of matter, as iron, sugar or common table salt. The same substance may occur in nature or in industry in a variety of forms which appear to have little in common, yet to us students in the field of chemistry, they are identical for they all consist of a material having a definite set of characteristics or properties.

Many naturally occurring materials are composed of two or more substances which can be easily separated. These specimens of matter are called complex substances. Table salt is an example of a complex substance since it can be separated chemically into sodium and chlorine. If, however, a body is composed of only one substance, it is said to be homogeneous, meaning that it cannot be decomposed. Such a body is called a simple substance.

ELEMENTS

Ninety-two of these simple substances which do not decompose are known to the chemists. These are the chemical elements, differing from one another in physical properties and chemical behavior and which can not be converted into simpler materials.

Every element is either metallic (iron, zinc, copper, etc.) or non-metallic (carbon, iodine, and sulfur). The word "metallic" makes us think of hard, heavy metals such as iron and lead, but not all metals have these characteristics. The metal, mercury, for example, is a liquid at ordinary temperatures; the metals, sodium and potassium are very soft. There are, nevertheless, common characteristics for these sixty odd metallic elements. All of them are reflectors of light (polished silver being the best), and all can conduct heat and electricity. Some of them such as copper and silver are better conductors, than the others. Also they are more or less malleable, that is, they can be beaten out under a hammer and are more or less ductile, which means that they can be drawn into wire. However, the degree of malleability and ductility varies widely. Gold, for example, can be easily hammered into sheets while antimony is so brittle that it crumbles into a powder when struck a hard


LIONEL CHEM-LAB 29

LIST OF ELEMENTS


Symbol
Symbol
Aluminum
Antimony
Argon
Arsenic
Barium
Beryllium 
Bismuth 
Boron
Bromine
Cadmium 
Calcium 
Carbon 
Cerium
Cesium 
Chlorine 
Chromium
Cobalt 
Columbium 
Copper 
Dysprosium 
Erbium  
Europium 
Fluorine 
Gadolinium 
Gallium
Germanium 
Gold 
Hafnium 
Helium 
Holmium
Hydrogen 
Indium 
Iodine 
Iridium 
Iron
Krypton
Lanthanum 
Lead 
Lithium
Lutecium
Magnesium
Manganese
Mercury
Al
Sb
A
As
Ba
Be
Bi
B
Br
Cd
Ca
C
Ce
Cs
Cl
Cr
Co
Cb
Cu
Dy
Er
Eu
F
Gd
Ga
Ge
Au
Hf
He
Ho
H
In
I
Ir
Fe
Kr
La
Pb
Li
Lu
Mg
Mn
Hg
Molybdenum 
Neodymium 
Neon 
Nickel 
Nitrogen 
Osmium
Oxygen 
Palladium 
Phosphorus 
Platinum 
Potassium
Praseodymium 
Protactinium
Radium 
Radon 
Rhenium 
Rhodium
Rubidium
Ruthenium
Samarium
Scandium
Selenium
Silicon
Silver
Sodium
Strontium
Sulfur
Tantalum 
Tellurium
Terbium 
Thallium
Thorium
Thulium
Tin
Titanium
Tungsten
Uranium
Vanadium
Xenon
Ytterbium
Yttrium
Zinc
Zirconium
Mm
Nd
Ne
Ni
N
Os
O
Pd
P
Pt
K
Pr
Pa
Ra
Rn
Re
Rh
Rb
Ru
Sm
Sc
Se
Si
Ag
Na
Sr
S
Ta
Te
Tb
T1
Th
Tm
Sn
Ti
W
U
V
Xe
Yb
Y
Zn
Zr


30 INTRODUCTION TO CHEMISTRY

blow. Copper may be drawn into a thin wire while lead has neither ductility nor tensile strength.

The oxygen that you breathe, the iodine that you paint on your cut finger, the sulfur that you burn when you strike a match - all three are examples of non-metallic elements. However, the real importance of this group of elements is their use as raw materials which man converts into thousands of useful compounds.

COMPOUNDS AND MIXTURES

The elements sodium and chlorine combine chemically to form common salt (sodium chloride), a chemical compound, which has altogether different properties than either of its component parts.

EXPERIMENT No. 27 A Chemical Compound

(CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Test tube, sulfur, powdered iron, candle or alcohol lamp.

PROCEDURE: Repeat Experiment No. 9.

SUMMARY: The new compound is iron sulfide or ferrous sulfide. It bears no resemblance to either the original sulfur or iron. The name tells us that iron and sulfur are constituents of the compound, iron sulfide.  

The changing of properties through chemical union and the necessity of new chemical reactions to decompose the final product are guiding steps by which we can tell the difference between a mixture and a compound. In a mixture, each of the substances exhibits its own specific properties and the term components of the mixture is applied to the substances which make up the mixture. 

EXPERIMENT No. 28 A Mixture of Sand And Sugar

(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)
 
APPARATUS: Sand and sugar.
 
PROCEDURE: Mix three measures each of sugar and sand on a piece of paper. Taste the mixture. 

SUMMARY: In a mixture, each component part maintains the same properties as when it exists alone. By tasting, you can tell that the sugar is still sugar and the sand is still sand. 

EXPERIMENT No. 29 Separating Sand And Sugar

(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Sand, sugar, a drinking glass.

PROCEDURE: Place three measures each of sand and sugar on a piece of paper. Mix well and place in a drinking glass. Add water.

LIONEL CHEM-LAB 31

SUMMARY: By adding water, the sugar is dissolved and when the liquid is poured off, the insoluble sand remains. Proof that it is sand alone can be obtained by tasting. The sugar will return to its original state if the water evaporates.

EXPERIMENT No. 30 Mixture Of Sand Powdered Iron

(CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Sulfur, powdered iron and a toy magnet.

PROCEDURE: Mix thoroughly three measures each of sulfur and powdered iron on a sheet of paper. Separate into two equal parts. Pass the magnet over one of the mixtures repeatedly. Place the other mixture in a small glass and add water. Note that sulfur has a tendency to float on the surface of the water, while the iron sinks to the bottom. Carefully pour off the water thus removing some of the sulfur. Repeat this procedure until only the iron remains in the glass.

SUMMARY: Powdered iron and sulfur can be mixed so thoroughly that the particles of each can only be distinguished with the use of a microscope. Nevertheless, the separating of these two elements is not difficult. Since iron is magnetic and sulfur is not, the iron can be removed by passing the magnet over the mixture, or by the addition of water, we can wash away the sulfur. Thus we have proved once more that the components of a mixture remain the same and can be separated.

ACIDS, BASES AND SALTS

We have seen that matter can be classified as elements, compounds and mixtures. For purposes of study, we can also subdivide compounds into three groups known as acids, bases, and salts.

Compounds known as acids derive their name from the Latin word acidus, meaning sour. All acids are compounds of hydrogen and another element from which they derive their name. Thus, hydrochloric acid is a compound of hydrogen and chlorine, sulfuric acid is a compound of hydrogen, sulfur and oxygen, nitric acid is a compound of hydrogen, nitrogen, and oxygen. Other common acids are citric acid which gives the sour taste to oranges, lemons and grapefruit, and acetic acid which is present in vinegar. Acids change blue litmus paper to red and combine with many materials to form compounds called salts.

EXPERIMENT No. 31 Characteristics Of Acids

(CL-44, CL-55, CL-66, CL-77)

APPARATUS: Tartaric acid, glass stirring rod, small glass, blue litmus paper.

PROCEDURE: Dissolve two measures of tartaric acid in a glass half

32 INTRODUCTION TO CHEMISTRY

filled with water. Place a drop on your tongue. Place a drop on some blue litmus paper and observe the color change.

SUMMARY: This experiment demonstrates that acids are sour and that they change blue litmus paper to red.

EXPERIMENT No. 32 Carbonic Acid

(CL-44, CL-55, CL-66, CL-77)

carbonic acid

FIGURE 7

APPARATUS: Sodium carbonate, sodium bisulfate, two test tubes, blue litmus paper, bent tubing and stopper (delivery tube).

PROCEDURE: Dissolve four measures of sodium carbonate and an equal amount of sodium bisulfate in test tube half filled with water. When the reaction starts, insert delivery tube and allow the long portion of tube to go into the second test tube, one-third filled with water.  Allow the gas to bubble up through the water. Place a few drops of the solution in the second test tube on your blue litmus paper. Note color change.

SUMMARY: Sodium carbonate, as we have noted in a previous experiment, gives off carbon dioxide gas when treated with an acid. It is this gas which causes the bubbling in the test tube. Moreover, the carbon dioxide combines with the water in the tube forming carbonic acid. This acid causes the blue litmus paper to turn red.

EXPERIMENT No. 33 An Acid From An Oxide

(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Sulfur, blue litmus paper, heating spoon, candle or alcohol lamp.

PROCEDURE: Place two measures of sulfur in the heating spoon.

LIONEL CHEM-LAB 33

Heat until sulfur melts. Hold a strip of moistened blue litmus paper over the spoon. Note the change in the color of the paper.

SUMMARY: The sulfur burns to form sulfur dioxide which reacts with the water on the blue litmus paper to form sulfurous acid which turns the litmus paper red.

EXPERIMENT No. 34 An Acid Produced By Double Decomposition

(CL-11, CL-22, CL-33. CL-44, CL-55, CL-66, CL-77)

APPARATUS: Sodium bisulfate, ammonium chloride, test tube, blue litmus paper, candle.

PROCEDURE: Place four measures of sodium bisulfate and three measures of ammonium chloride in a test tube. Add a few drops of water. Heat cautiously for a few seconds. Hold blue litmus paper over the mouth of the tube. Note the color change.

SUMMARY: Ammonium chloride reacts with sodium bisulfate, an acid salt, to liberate hydrochloric acid fumes which turn blue litmus paper red.

BASES

Bases, the opposite of acids, turn red litmus blue and are distinguished by the name hydroxide, that is, sodium hydroxide, potassium hydroxide, calcium hydroxide, etc. Alkali is a term also used in referring to bases of the metals. 

The most important property of bases is that, when combined with an acid, they neutralize each other and lose their characteristic properties to form a compound called a salt.

EXPERIMENT No. 35 Properties Of Bases

(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Ammonium hydroxide (or household ammonia), test tube, red litmus paper.

PROCEDURE: Add ten drops of ammonium hydroxide to a test tube half filled with water. Place two or three drops of the solution on red litmus paper.

SUMMARY: This solution, a base, turns red litmus paper blue.

EXPERIMENT No. 36 A Base From An Oxide

(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Calcium oxide, test tube, red litmus paper.

PROCEDURE: Dissolve two measures of calcium oxide in a test tube half filled with water. Place one or two drops of this solution on a small piece of red litmus paper. Note the color change.

SUMMARY: Calcium oxide in water forms a base, calcium hydroxide.


34 INTRODUCTION TO CHEMISTRY

EXPERIMENT No. 37 A Base Produced By Double Decomposition 

(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Calcium oxide, sodium carbonate, two test tubes, candle.

PROCEDURE: Place three measures of calcium oxide and three measures of sodium carbonate in a test tube one-quarter filled with water. Boil the solution for a few minutes. Allow contents to cool. Pour off the clear solution into another test tube. Place a few drops of the solution on your finger tips and rub back and forth. Remove solution from hands by washing immediately.

SUMMARY: In this experiment calcium oxide combines with water to form calcium hydroxide which in turn reacts with the sodium carbonate to form two new compounds, calcium carbonate, the salt which settles at the bottom of the tube, and sodium hydroxide, the base which gives a soapy feeling to your hands.

SALTS AND NEUTRALIZATION

Our third classification is that of a salt. The name given to the reaction occurring when an acid and base are brought together to form a salt is neutralization

For example, hydrochloric acid and sodium hydroxide neutralize each other to form sodium chloride (table salt) and water.

EXPERIMENT No. 38 Formation Of A Salt

(CL-44, CL-55, CL-66, CL-77)

APPARATUS: Calcium oxide, test tube, acetic acid.

PROCEDURE: Dissolve one measure of calcium oxide in a test tube one third filled with water. Make the solution acid by dissolving in it one or two drops of acetic acid. Note how clear the solution becomes.

SUMMARY: Chemically speaking, a salt is a compound obtained by the displacement of the hydrogen from an acid by the metal of a base.  In this experiment, the calcium oxide combines with water to form calcium hydroxide. This base reacts with the acetic acid forming water and the salt, calcium acetate. Since calcium acetate is soluble in water, the solution becomes clear.

EXPERIMENT No. 39 Neutralization Of An Acid

(CL-44, CL-55, CL-66, CL-77)

APPARATUS: Tartaric acid, phenolphthalein solution, ammonium hydroxide (or household ammonia), test tube.

PROCEDURE: Dissolve a measure of tartaric acid in a test tube half filled with water. Add one drop of phenolphthalein solution. Add ammonium hydroxide one drop at a time until the solution shows a faint pink color. Continue adding one or two more drops of the ammonium hydroxide, until the solution becomes a darker pink.

LIONEL CHEM-LAB 35

SUMMARY: In this experiment, ammonium hydroxide reacted with tartaric acid to form water and ammonium tartrate, a base whose presence is detected by the phenolphthalein which turns red in alkaline solutions. Naturally, the more ammonium hydroxide is placed in the test tube, the more alkaline the solution becomes and thus the more intense the red indicator of phenolphthalein.

EXPERIMENT No. 40 Hydrolysis Of Ammonium Chloride

(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Ammonium chloride, test tube, blue litmus paper, candle or alcohol lamp.

PROCEDURE: Dissolve five measures of ammonium chloride in a test tube one quarter filled with water. Heat slowly. Put a drop of this solution on a piece of blue litmus paper.

SUMMARY: Hydrolysis is the ability of water to break down a salt to form an acid and a base. If the acid is stronger than the base, it will test acid. If the reverse is true it will have a basic reaction. In this case, ammonium chloride combined with water to form ammonium hydroxide and hydrochloric acid. Since the acid is stronger, the solution turns blue litmus red.

EXPERIMENT No. 41 Hydrolysis Of Sodium Carbonate

(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Sodium carbonate, test tube, red litmus paper.

PROCEDURE: Dissolve two measures of sodium carbonate in a test tube half filled with water. Place one drop of this solution on a piece of red litmus paper.

SUMMARY: This is an example of hydrolysis giving an alkaline solution. The sodium carbonate, a salt of a weak acid and a strong base, combines with water to form carbonic acid and sodium hydroxide, the latter being a very strong base giving the solution an alkaline reaction, which turns the red paper blue.

EXPERIMENT No. 42 Hydrolysis Of Ferric Ammonium Sulfate

(CL-11, CL-22, CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Ferric ammonium sulfate, three test tubes, candle or alcohol lamp.

PROCEDURE: Dissolve two measures of ferric ammonium sulfate in a test tube one quarter filled with water. Fill two other test tubes half full of water. Heat one of them to boiling point. Add to both test tubes one drop of ferric ammonium sulfate solution. Set the tubes in the test tube rack. Note the orange precipitate in the test tube containing the hot water.

SUMMARY: Ferric ammonium sulfate undergoes hydrolysis in the presence of, or mixed with, hot water. Ferric hydroxide is the orange

36 INTRODUCTION TO CHEMISTRY

colored precipitate while the clear liquid is sulfuric acid in solution.  The ammonium sulfate in the tube containing cold water remains clear and unaltered.

EXPERIMENT No. 43 Interchange Of Elements

(CL-33, CL-44, CL-55, CL-66, CL-77)

APPARATUS: Sodium carbonate, strontium chloride, two test tubes.

PROCEDURE: Dissolve one measure of sodium carbonate in a test tube one quarter filled with water. Dissolve in another test tube one measure of strontium chloride in the same amount of water. Pour the strontium chloride into the test tube containing the sodium carbonate and set aside. Note the formation of a white precipitate at the bottom of the tube.

SUMMARY: The two compounds exchange elements forming sodium chloride, which remains dissolved in the water, and strontium carbonate which because of its insolubility settles at the bottom of the test tube.

LITMUS PAPER AND OTHER INDICATORS

We have mentioned that one of the characteristics of acids is that it turns blue litmus paper red and that bases turn the red back to blue. This is a common chemical test to discover whether a given solution is acid or basic. Of course, it is also used to decide whether or not a solution is neutral because such solutions have no effect on either blue or red litmus paper. Any material which changes color in the presence of an acid or a base is known as an indicator. Indicating papers used by chemists, such as red and blue litmus, are prepared by soaking pieces of absorbent paper in the particular indicator solution desired.

EXPERIMENT No. 44 A Solution Of Cochineal

(CL-77)

APPARATUS: Cochineal, sodium carbonate, tartaric acid, test tube.

PROCEDURE: Place one half measure of cochineal in a test tube one quarter filled with water. Heat the solution until it becomes very red. Pour off the clear solution into another test tube and add a half measure of sodium carbonate. Now add one measure of tartaric acid and observe all color changes.

SUMMARY: Cochineal comes from the dried bodies of certain insects of Central Mexico. It has the property of turning violet in the presence of alkalies such as sodium carbonate, and a reddish-orange in the presence of acids.

EXPERIMENT No. 45 Cochineal Paper

(CL-77)

LIONEL CHEM-LAB 37

APPARATUS: Cochineal, sodium carbonate, tartaric acid, test tube, filter paper, candle or alcohol lamp.

PROCEDURE: Place one measure of cochineal in test tube half filled with water. Heat until the solution becomes red. Dip a strip of filter paper into the solution and allow paper to dry. Test paper with a small portion of moistened sodium carbonate. Repeat with moistened tartaric acid. Note the color changes.

SUMMARY: Cochineal paper can be used instead of cochineal solution when the latter is less desirable. Both have the same property of changing alkaline solutions violet and acid solutions reddish-orange.

EXPERIMENT No. 46 Logwood

(CL-44, CL-55, CL-66, CL-77)

APPARATUS: Logwood, two test tubes, sodium carbonate, tartaric acid.

PROCEDURE: Place a small chip of logwood in a test tube half filled with water. Heat until the liquid becomes deep red. Pour the clear red solution into another test tube. Add one measure of sodium carbonate and two measures of tartaric acid.

SUMMARY: Logwood comes from the bark of a tree in the West Indies. Its coloring matter has the property of turning reddish-blue in an alkaline solution and reddish-brown in an acid solution.

EXPERIMENT No. 47 Logwood Paper

(CL-44, CL-55, CL-G6, CL-77)

APPARATUS: Logwood, filter paper, sodium bisulfate, sodium carbonate, candle.

PROCEDURE: Place a small chip of logwood in a test tube half filled with water. Boil the liquid for a few minutes. Dip a strip of filter paper into the liquid. Dry the paper and cut in two. On one piece put a half measure of sodium carbonate. Sprinkle with water. Note the change in color. On the other piece, place a half measure of sodium bisulfate. Sprinkle with water. Note the color change.

SUMMARY: The alkaline, sodium carbonate, turns the logwood paper reddish-blue while the acid, sodium bisulfate, causes it to change to a reddish-brown.

EXPERIMENT No. 48 Congo Red Paper

(CL-44, CL-55, CL-66, CL-77)

APPARATUS: Congo red paper, tartaric acid, sodium carbonate, small glass.

PROCEDURE: Immerse a piece of congo red paper in a glass half filled with water. Add two measures of tartaric acid. Stir and note change in color. Now add three measures of sodium carbonate. Stir and again note change in color.

38 INTRODUCTION TO CHEMISTRY

SUMMARY: Congo red paper is made by staining white paper with a dye made from coal tar. It has the opposite color effect of litmus, being red in the presence of an alkaline solution and blue in an acid solution.

EXPERIMENT No. 49 Turmeric Paper

(CL-55, CL-66, CL-77)

APPARATUS: Sodium carbonate, turmeric paper, tartaric acid, small glass.

PROCEDURE: Dissolve two measures of sodium carbonate in a glass one-quarter filled with water. Drop in a piece of turmeric paper. Stir and note change. Now add four measures of tartaric acid. Stir and again note change.

SUMMARY: The coloring matter of turmeric paper comes from the root of a plant of the Far East. It becomes brown in an alkaline solution and yellow in acid solutions. Besides being used as a test paper, this pigment is employed as a coloring agent for mustard.

EXPERIMENT No. 50 Litmus Paper

(CL-44, CL-55, CL-66, CL-77)

APPARATUS: Blue litmus paper, tartaric acid, sodium carbonate, red litmus paper, small glass.

PROCEDURE: Immerse a piece of blue litmus paper in a glass half full of water. Add one measure of tartaric acid. Stir and note color change. Add two measures of sodium carbonate. Stir and observe the change in color.

SUMMARY: When acid is added to water, blue litmus paper turns red and when sodium carbonate is placed in the glass, the strip of litmus returns to its original red color. Thus we can readily ascertain whether a solution is acid, base or neutral by its action on litmus paper.

EXPERIMENT No. 51 Phenolphthalein

(CL-44, CL-55, CL-66, CL-77)

APPARATUS: Phenolphthalein solution, calcium oxide, tartaric acid, small glass.

PROCEDURE: Put three drops of phenolphthalein solution in a glass half filled with water. Add three measures of calcium oxide. Stir and note change in color. Add three measures of tartaric acid. Stir and again note color change.

SUMMARY: Phenolphthalein turns red in the presence of bases, and colorless in the presence of acids.

EXPERIMENT No. 52 Phenolphthalein Paper

(CL-44, CL-55, CL-66, CL-77)

APPARATUS: Calcium oxide, phenolphthalein solution, filter paper.

LIONEL CHEM-LAB 39

PROCEDURE: Dip some filter paper into the phenolphthalein solution.  Allow to dry. Place a half measure of calcium oxide on this paper. Sprinkle a few drops of water over it. Note the color change.

SUMMARY: This is a handy method of testing with phenolphthalein when the solution method is less desirable. Make some test paper to keep on hand.

EXPERIMENT No. 53 Testing Laxatives

(CL-1, CL-2, CL-3 1/2, CL-5, CL-7 1/2, CL-10, CL-15)

APPARATUS: Sodium carbonate, laxative tablet (from neighborhood drug store), small glass.

PROCEDURE: Cut tablet into small pieces and place in glass half filled with water. Stir carefully for a few minutes and then add one measure of sodium carbonate.

SUMMARY: Some chewing-gum and candy laxatives contain phenolphthalein. The presence of this substance will be indicated if the solution becomes red after adding the sodium carbonate.

CAUSTIC ACIDS AND BASES

Certain acids and bases when full strength are caustic poisons and must not be handled with the bare hands. Examples of these are the acids hydrochloric, sulfuric, nitric and acetic. Among the bases, sodium hydroxide and potassium hydroxide, otherwise known as caustic soda and caustic potash, are also dangerous to handle. 

When these materials are supplied in Lionel Chem-Lab sets or produced in any of the experiments, the solutions are so weak and dilute that they are absolutely harmless.


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