The Science Notebook
  Lionel Chem-Lab - Chapter 8

  Home   Terms of Use   Safety  Contact Us   Experiment Pages   Downloads   Supplies   Useful Links!


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  In addition, much of the information contained in this book about chemistry and other subjects is outdated and some of it is inaccurate.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 121- 136

CHAPTER VIII

SULFUR

Sulfur is one of the most important elements and also one of the most common. Physically, it is a pale-yellow solid with no particular taste or odor.

There is a greater distribution of sulfur in combination with other elements than in the pure state. For example, there are numerous metallic ores which are sulfides: lead sulfide (galena), zinc sulfide, and iron pyrites used in making sulfuric acid. Many organic substances in the plant and animal world also contain sulfur. Every boy recognizes hydrogen sulfide because it has the disagreeable odor of rotten eggs.

You may recall also that certain foods like eggs blacken silver spoons. This is due to the fact that sulfur is present in these foods and reacts with the silver to form silver sulfide, a black precipitate.

Sulfur is very valuable in the commercial and industrial world being used in the manufacture of sulfuric acid, many medicinal products, and to some extent for fireworks, matches and gun powder.

HOW SULFUR IS MINED

Sulfur occurs free in volcanic areas impregnating the rocks. In Texas and Louisiana, the Frasch process for the extraction of sulfur has been developed after many years of experimentation amid the difficulties of quicksand and poisonous gas. This process employs three concentric steel pipes sunk four or five hundred feet below the surface of the ground into the deposits. Superheated water is driven down through the outside pipe and when it reaches the sulfur, melts it so that it can be easily pumped to the surface. The melted sulfur then is allowed to solidify into huge bins fifty feet high, built of planks, and the solid sulfur forms a block which may contain as much as 100,000 tons. For shipping, it is broken up by blasting with dynamite. Sulfur mined in this fashion is so pure that for general purposes it needs no refining.

FORMS OF SULFUR

Solid sulfur occurs in three different allotropic forms: rhombic, prismatic (or monoclinic), and amorphous (or plastic). The large crystals shown in

121


122 SULFUR

the photograph are rhombic; the prismatic or monoclinic variety has needle-shaped crystals while the amorphous sulfur, as its name implies, is rubbery and non-crystalline.  These allotropic forms of sulfur exhibit widely varying physical properties (color, shape, texture, solubility and stability) but have identical chemical properties.

sulfur crystals

Rhombic Sulfur Crystals

EXPERIMENT No. 225 Making Elastic Sulfur

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

APPARATUS: Sulfur, test tube, alcohol lamp or candle.

PROCEDURE: Place four measures of sulfur in a dry test tube. Heat quickly until all the solid has melted and the color of the sulfur is changing. Quickly pour the contents into a glass of water.

SUMMARY: Note the elasticity of the sulfur due to the change in temperature.

EXPERIMENT No. 226 Allotropic Transformation Of Sulfur

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

APPARATUS: Sulfur, candle or alcohol lamp, test tube.

PROCEDURE: Place six measures of sulfur into a dry test tube. Cautiously apply heat. Continue heating and note the various stages that the sulfur passes through, 

LIONEL CHEM-LAB  123

french process of sulfur extraction

Diagram of the Frasch Process


124 SULFUR

SUMMARY: Sulfur upon heating first melts to a pale yellow liquid which gradually changes to a dark and viscous substance. Application of more heat converts this into a vapor which condenses as it touches the cool upper portions of the test tube.

EXPERIMENT No. 227 Preparation Of Monoclinic Sulfur

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

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

PROCEDURE: Place four measures of sulfur in your heating spoon. Slowly heat the sulfur until it reaches the melting point, then remove from flame immediately. Pour the liquid on a piece of paper. Examine crystals.

SUMMARY: As explained above, sulfur exists in two solid forms: monoclinic and rhombic. The monoclinic melts at 119 degrees and if cooled quickly it will form needle-like crystals.

EXPERIMENT No. 228 Preparation Of Rhombic Sulfur

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

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

PROCEDURE: Place four measures of sulfur in your heating spoon. Heat the sulfur slowly. When the sulfur begins to melt, withdraw the spoon from flame and pour contents into a glass of water. Examine the crystals.

SUMMARY: Rhombic sulfur crystals are formed when sulfur is heated to 112 degrees. If monoclinic crystals are kept overnight they will form rhombic crystals at room temperature.

EXPERIMENT No. 229 Plastic Sulfur

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

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

PROCEDURE: Place five measures of sulfur in the heating spoon and apply heat carefully until sulfur melts. Pour this into a glass of cold water. Remove the sulfur and test it by touch. Set it aside and from time to time note whether any changes occur.

SUMMARY: When boiling sulfur is suddenly cooled by pouring it into cold water, it assumes a rubbery, plastic form which is non-crystalline. This is not a stable state because upon standing, the plastic sulfur changes back into rhombic sulfur.

EXPERIMENT No. 230 A Chemical Property of Sulfur

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


LIONEL CHEM-LAB 125

APPARATUS: Sodium nitrate, sulfur, heating spoon, alcohol lamp or candle, gas generator bottle, test tubes.

PROCEDURE: Place three measures of sodium nitrate in the gas generator bottle. Heat the contents thoroughly and collect the gas in two clean test tubes. Reject the first test tube of gas collected as it is composed largely of air which was present in your gas generator bottle. Invert the second test tube to keep the gas from dissipating. Place some sulfur in your heating spoon. Heat slowly unt1l the sulfur begins to glow. Quickly drop the sulfur into the test tube containing the gas.

SUMMARY: Note how sulfur ignites in the presence of oxygen (produced when sodium nitrate was heated).

EXPERIMENT No. 231 Sulfur Soluble In Carbon Tetrachloride

(CL-66, CL-77)

APPARATUS: Carbon tetrachloride, test tube, sulfur and saucer.

PROCEDURE: Place a pin head amount of sulfur in a test tube containing half an inch of carbon tetrachloride. Shake the test tube vigorously at intervals and note whether the sulfur is dissolved. Pour the contents into a saucer and allow the liquid to evaporate. Note the sulfur residue on the saucer.

SUMMARY: Sulfur is practically insoluble in water but readily so in carbon tetrachloride.

EXPERIMENT No. 232 Making Sulfur From Two Gases

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

APPARATUS: Sodium bisulfite, sodium bisulfate, test tube, paraffin, sulfur, candle or alcohol lamp, gas delivery tube and stopper.

PROCEDURE: Place three measures of sodium bisulfite and three measures of sodium bisulfate into a test tube. Pour in a few drops of water and inhale cautiously the odor given off. Put a small piece of paraffin and four measures of sulfur into another test tube. Attach gas delivery tube and stopper to the test tube containing the paraffin. Heat gently. After noting the odor given off, run the long stem of the delivery tube into the test tube containing the sodium bisulfate. Note the sulfur formation when the two gases come in contact with one another.

SUMMARY: The gases formed are sulfur dioxide and hydrogen sulfide respectively and when they are brought into contact with one another they form the products, sulfur and water.

HYDROGEN SULFIDE

When sulfur combines with hydrogen, hydrogen sulfide, a colorless gas with a disagreeable taste and odor is formed. A very poisonous gas if inhaled in quantity, it produces headache, dizziness, and nausea.


126 SULFUR

Hydrogen sulfide is a constituent of volcanic gas and is sometimes found in spring water. It is generally a product of decaying organic matter which contains sulfur. In the laboratory, hydrogen sulfide is very important to the chemist because by bubbling this gas through a salt solution, sulfides, the salts of sulfuric acid are formed. Hydrogen sulfide decomposes easily and has a strong tendency to combine with oxygen, thus it is a good reducing agent.

EXPERIMENT No. 233 Preparation Of Hydrogen Sulfide

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

APPARATUS: Paraffin, sulfur, test tube and candle or alcohol lamp.

PROCEDURE: Place a small piece of paraffin and four measures of sulfur in a test tube. Heat gently for a minute or two. Remove test tube from flame and note the gas which is given off.

SUMMARY: When paraffin, a hydrocarbon, is heated, hydrogen is liberated which reacts with sulfur to form hydrogen sulfide.

EXPERIMENT No. 234 Hydrogen Sulfide In Illuminating Gas

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

APPARATUS: Sulfide test paper, illuminating gas.

PROCEDURE: Briefly open a gas jet and quickly expose some moistened sulfide test paper to the gas. Turn jet off immediately. Note whether the paper changes color.

SUMMARY: If the illuminating gas contains hydrogen sulfide, a black spot will appear on the moistened sulfide test paper.

EXPERIMENT No. 235 Another Way To Make Hydrogen Sulfide

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

APPARATUS: Iron sulfide, hydrochloric acid, sulfide test paper and test tube.

PROCEDURE: Add a few drops of hydrochloric acid to a test tube containing one measure of iron sulfide. Place some moistened sulfide test paper to the mouth of the test tube and note the color.

SUMMARY: The sulfur of the iron sulfide reacts with the hydrogen of the hydrochloric acid to form hydrogen sulfide gas which turns the moistened sulfide test paper a brownish-black color.

EXPERIMENT No. 236 Hydrogen Sulfide From Iron Pyrites

(CL-66, CL-77)

APPARATUS: Iron pyrites, hydrochloric acid, test tube, alcohol lamp or candle.

PROCEDURE: Place a half measure of iron pyrites in a test tube. Add six drops of hydrochloric acid.


LIONEL CHEM-LAB  127

SUMMARY: Note the odor of the gas formed which is hydrogen sulfide. The explanation for this reaction is as follows: Iron pyrites, composed of iron and sulfur reacts with hydrochloric acid to form iron chloride and hydrogen sulfide.

EXPERIMENT N0. 237 Hydrogen Sulfide From Boiling Cabbage

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

APPARATUS: Sulfide test paper and cabbage.

PROCEDURE: Place a strip of moistened sulfide test paper in the steam of cooking cabbage. Note that a black spot appears on the paper.

SUMMARY: Hydrogen sulfide, present in the cabbage, reacts with moistened sulfide test paper turning it black.

EXPERIMENT No. 238 Acid Properties Of Hydrogen Sulfide

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

APPARATUS: Blue litmus paper, test tube, sulfur, paraffin, candle or alcohol lamp.

PROCEDURE: Place a small piece of paraffin and four measures of sulfur in a test tube. Heat gently passing the gas through the delivery tube into a test tube containing blue litmus paper and one inch of water. Collect the gas in this tube and note that the litmus paper and turns red.

SUMMARY: Hydrogen sulfide solution turns blue litmus paper red proving that the solution is acid.

EXPERIMENT No. 239 Testing For Hydrogen Sulfide

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

APPARATUS: Sulfide test paper, sulfur, paraffin, test tube, and candle or alcohol lamp.

PROCEDURE: Place a small piece of paraffin and four measures of sulfur in a test tube. Heat gently for a minute or two. Insert a moistened piece of sulfide test paper into the mouth of the tube and note the black color reaction.

EXPERIMENT No. 240 Burning Hydrogen Sulfide

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

APPARATUS: Test tube, test tube holder, delivery tube and stopper, sulfur, paraffin, drinking glass and candle or alcohol lamp.

PROCEDURE: Place a small piece of paraffin and four measures of sulfur in a test tube. Heat gently and insert the delivery tube and stopper. Ignite the gas which escapes from the long stem of the delivery tube and note that it burns with a pale blue flame. Place the side of a cold glass in the blue flame and note whether any sulfur is deposited on it.


128 SULFUR

SUMMARY: Hydrogen sulfide burns with a pale blue flame in the presence of air and the products formed are sulfur dioxide and water. However, when the amount of air is limited it liberates free sulfur which settles out as a yellow powder.

EXPERIMENT No. 241 Chlorine Reacts With Hydrogen Sulfide
(CL-55, CL-66, CL-77)

APPARATUS: Sulfur, paraffin, gas delivery tube and stopper, test tubes, tartaric acid, calcium hypochlorite and candle or alcohol lamp.

PROCEDURE: Place a small piece of paraffin and four measures of sulfur in a test tube. Insert the stopper and delivery tube with the long stem going into another test tube one-quarter full of water and apply heat gently. Allow the reaction to continue for awhile. Put two measures of calcium hypochlorite and an equal amount of tartaric acid in a test tube and add a little water. Transfer the delivery tube and stopper to this test tube allowing the chlorine to bubble into the hydrogen sulfide solution. Note the cloudiness of the liquid.

SUMMARY: When chlorine is passed through hydrogen sulfide solution, the products formed are hydrochloric acid and sulfur. Some of the sulfur settles as a white precipitate and some of it remains suspended in the liquid causing the cloudiness.

OTHER SULFIDES

Sulfides can also be formed by the action of hydrogen sulfide upon metals. Silver sulfide is the black tarnish which appears on silverware due to the presence of small amounts of hydrogen sulfide in the air and in illuminating gas.

EXPERIMENT No. 242 Tarnishing Metals With Hydrogen Sulfide

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

APPARATUS: Sulfur, paraffin, test tube, candle or alcohol lamp and bright silver coin.

PROCEDURE: Place a small piece of paraffin and four measures of sulfur in a test tube. Heat gently. As the gas escapes, hold the moistened silver coin at the mouth of the test tube. Within a minute or so, you will note that a black stain appears on the coin.

SUMMARY: This black stain is silver sulfide formed when the hydrogen sulfide gas reacts with the silver of the coin.

EXPERIMENT No. 243 Proving That Matches Contain Sulfur

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

APPARATUS: Safety matches, test tube, silver coin, candle or alcohol lamp.


LIONEL CHEM-LAB 129

PROCEDURE: Remove the heads of five safety matches and place them in a test tube with several drops of water. Shake the tube until a thin paste is formed. Place several drops of paste on the silver coin and heat the coin until the paste begins to burn. Note the blackness of the coin.

SUMMARY: Silver sulfide was formed when the sulfur in the matches combined with the silver of the coin.

EXPERIMENT No. 244  Another Silver Sulfide Experiment

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

APPARATUS: Sulfur, silver coin and paper.

PROCEDURE: Place one measure of sulfur on a silver coin and wrap in several layers of paper. Set aside for several minutes. Unfold the paper and note the mark on the coin.

EXPERIMENT No. 245 Heating Iron Pyrites

(CL-66, CL-77)

APPARATUS: Iron pyrites, candle or alcohol lamp and test tube.

PROCEDURE: Place one measure of iron pyrites in a test tube. Heat gently. Note the sulfur on the inside walls of test tube. Stop heating and cautiously smell the odor coming from the tube.

SUMMARY: Sulfur and iron react to form iron disulfide (iron pyrites) which occurs abundantly in nature as yellow crystals, often called "fools gold". When heated in a test tube, sulfur is liberated, most of which is oxidized to the gas, sulfur dioxide.

EXPERIMENT No. 246 Distinguishing Pyrites From Gold

(CL-66, CL-77)

APPARATUS: Iron pyrites, hammer, glass, test tube, alcohol lamp or candle.

PROCEDURE: Place one measure of iron pyrites in a test tube and heat carefully. Note the sulfur formed on the inside walls of the test tube and the strong odor given off. Carefully spread the material on a wooden block. Pulverize the material with a hammer. Scratch a piece of glass with a small piece of solid pyrites and note the marked surface.

SUMMARY: Compare these properties with the properties of gold. Gold does not contain sulfide like iron pyrites, therefore, no decomposition occurs when gold is heated, Gold is malleable, therefore, it can be flattened out and not easily crushed to powder. Gold is soft, therefore, it cannot scratch glass.

EXPERIMENT No. 247 Manganese Sulfide

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


130 SULFUR

APPARATUS: Manganese sulfate, test tube, sodium carbonate, sulfur, paraffin, alcohol lamp or candle, stopper and delivery tube.

PROCEDURE: Dissolve two measures of manganese sulfate in a test tube half full of warm water. Add a measure of sodium carbonate and note the white precipitate. Put a small piece of paraffin and four measures of sulfur into another test tube and insert the delivery tube and stopper. Heat and allow the gas to bubble into the tube containing the precipitate. Note the pale pink precipitate.

SUMMARY: The white precipitate which forms first is manganese carbonate. Hydrogen sulfide changes the precipitate to manganese sulfide, a pale pink substance.

EXPERIMENT No. 248 Nickel Sulfide

(CL-66, CL-77)

APPARATUS: Nickle chloride, paraffin, sulfur, test tubes, candle or alcohol lamp.

PROCEDURE: Place four measures of sulfur and a small piece of paraffin in a test tube. Heat gently for a few minutes. Dissolve two measures of nickel chloride in a test tube half full of water. Introduce the hydrogen sulfide into the solution. Note the black precipitate of nickel sulfide.

EXPERIMENT No. 249 Testing Rubber For Sulfur

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

APPARATUS: Rubber band, a penny, alcohol lamp or candle, heating spoon.

PROCEDURE: Cut the rubber band into small pieces. Place the rubber and a bright penny in the heating spoon. Heat slowly over a small flame. Stop heating when the odor of burnt rubber is noticeable. Examine the penny and note the black color.

SUMMARY: The sulfur from the rubber reacts with the copper of the penny to form copper sulfide.

EXPERIMENT No. 250 Reaction Of Copper And Sulfur

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

APPARATUS: Sulfur, copper metal, test tube, candle or alcohol lamp.

PROCEDURE: Put half a measure of sulfur on one end of the strip of copper. Hold the strip with the test tube holder and heat until the sulfur melts. Allow to cool and note the black film of copper sulfide left after the sulfur is scraped off.

EXPERIMENT No. 251 Copper Sulfide Preparation

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

APPARATUS: Copper sulfate, candle or alcohol lamp, sulfur, paraffin, test tube, gas delivery tube and stopper. 


LIONEL CHEM-LAB 131

PROCEDURE: Dissolve a few crystals of copper sulfate in a test tube one quarter filled with water. Place a small piece of paraffin and four measures of sulfur in another test tube. Insert the stopper and delivery tube so that the long stem runs into the test tube containing the copper sulfate solution and heat carefully. Note the formation of a black precipitate of copper sulfide.

EXPERIMENT No. 252 Cobalt Sulfide

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

APPARATUS: Cobalt chloride, sodium carbonate, test tube, paraffin, sulfur, alcohol lamp or candle, delivery tube and stopper.

PROCEDURE: Dissolve a measure of cobalt chloride in a test tube half full of water. Add a measure of sodium carbonate and note the blue precipitate of cobalt carbonate. Put a small piece of paraffin and four measures of sulfur into another test tube and insert the delivery tube and stopper. Heat and allow the hydrogen sulfide gas to pass into the precipitate.

SUMMARY: Cobalt sulfide is formed by the action of the hydrogen sulfide on cobalt carbonate.

EXPERIMENT No. 253 Zinc Sulfide

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

APPARATUS: Zinc metal, sodium bisulfate, sulfur, paraffin, alcohol lamp or candle, stopper and delivery tube, medicine dropper.

PROCEDURE: Place a small piece of zinc and four measures of sodium bisulfate in a test tube one third full of water. Heat until some of the zinc dissolves. Pour off the clear solution into another test tube. Place a small piece of paraffin and four measures of sulfur in a third test tube. Attach delivery tube and stopper. Heat and allow the gas to bubble into the zinc solution. Note the white precipitate of zinc sulfide.

EXPERIMENT No. 254 The Reaction Between Sulfur And Iron

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

APPARATUS: Sulfur, iron powder, heating spoon and alcohol lamp or candle.

PROCEDURE: Mix one half measure of iron powder and two measures of sulfur on a clean sheet of paper. Transfer them to the heating spoon and heat slowly. Note the reaction between iron and sulfur to form ferric sulfide.

EXPERIMENT No. 255 Ferrous Sulfide

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

APPARATUS: Ferrous ammonium sulfate, test tube, sodium carbonate, paraffin, sulfur, delivery tube and stopper, candle or alcohol lamp.


132 SULFUR

PROCEDURE: Place two measures of ferrous ammonium sulfate in a test tube half filled with water and shake to dissolve. Add a measure of sodium carbonate and note the green precipitate. Put a small piece of paraffin and four measures of sulfur into another test tube. Fit the delivery tube and stopper into the test tube and heat, allowing the hydrogen sulfide gas to pass into the precipitate.

SUMMARY: Sodium carbonate reacts with ferrous ammonium carbonate to form a green precipitate, ferrous carbonate. When treated with hydrogen sulfide gas, black ferrous sulfide is formed.

EXPERIMENT No. 256 Ferrous Sulfide From Sodium Thiosulfate

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

APPARATUS: Sodium thiosulfate, ferrous ammonium sulfate and sodium carbonate, test tube, candle or alcohol lamp.

PROCEDURE: Place one measure of sodium thiosulfate and an equal amount of ferrous ammonium sulfate in a test tube half full of water and shake to dissolve. Note the green precipitate formed when a measure of sodium carbonate is added to this. Heat to boiling and note how the color changes to black. In this case, the hydrogen sulfide gas is formed from sodium thiosulfate.

EXPERIMENT No. 257 Hydrogen Sulfide From Sodium Thiosulfate 

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

APPARATUS: Sodium thiosulfate, sulfide test paper and test tube.

PROCEDURE: Heat a test tube containing two measures of sodium thiosulfate. Note the water which appears as the heating continues and the change in the color of the solid. Remove from flame and cautiously smell the odor given off. Insert a moistened piece of sulfide test paper in the mouth of the tube and note the change in color denoting the presence of hydrogen sulfide. 

Sulfur dioxide and sulfur trioxide are two well-known oxides of sulfur.  When combined with water, they form sulfuric acid and sulfurous acid, those tremendously important acids used by the chemical industry.

SULFUR DIOXIDE

Sulfur dioxide is a stable, colorless gas with a strong suffocating odor, almost twice as heavy as air, and very soluble in water. In liquid form, for commercial use, it is transported in tank cars.

Similar to hydrogen sulfide in that it is found in volcanic gases and in sulfur spring waters, sulfur dioxide can be prepared either by burning sulfur in the air or by the reduction of sulfuric acid. Some of its important commercial uses in addition to the making of sulfuric acid are for bleaching, the preserving of foods, for disinfecting, and in place of ammonia as a refrigerant.


LIONEL CHEM-LAB 133

EXPERIMENT No. 258 Making Sulfur Dioxide

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

APPARATUS; Sulfur, candle or alcohol lamp and heating spoon.

PROCEDURE: Place a measure of sulfur in the heating spoon. Heat carefully until the sulfur melts and burns. Note the odor given off.

SUMMARY: When sulfur is heated in air or oxygen, sulfur dioxide gas is formed which can be recognized by its irritating odor.

EXPERIMENT No. 259 Chemical Properties Of Sulfur Dioxide

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

APPARATUS: Sulfur, red carnation or rose, alcohol lamp or candle.

PROCEDURE: Place two measures of sulfur in a test tube. Heat the contents. Moisten some carnation or rose petals and place at the mouth of the test tube. Note how the sulfur dioxide gas bleaches the flower.

EXPERIMENT No. 260 Sulfur Dioxide From A Bisulfite

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

APPARATUS: Sodium bisulfate, sodium bisulfite, test tube and an eye dropper.

PROCEDURE: Add four or five drops of water to a test tube containing two measures of sodium bisulfite. Shake well and add two measure of sodium bisulfate. Note the reaction. Smell cautiously the odor coming from the mouth of the tube.

SUMMARY: When sodium bisulfate is added to water, the liquid becomes acid. Sodium bisulfite in the presence of this acid liberates sulfur dioxide gas.

EXPERIMENT No. 261 Bleaching With Sulfur Dioxide

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

APPARATUS: Gas generator bottle, delivery tube and stopper, tumbler, colored paper, sodium bisulfite, vinegar and funnel.

PROCEDURE: Place the colored paper in the tumbler and add a few drops of water. Put six measures of sodium bisulfite in the gas generator bottle and pour in one half inch of water. Insert the stopper with the delivery tube and funnel, the bottom of which must go below the surface of the liquid. Place a piece of cardboard over the tumbler passing the delivery tube into the glass through a hole in the cardboard. Now, using the funnel, add some vinegar to the generator bottle. Note the bleaching which occurs in the tumbler as the gas enters.

SUMMARY: Sulfur dioxide, a good reducing agent, bleaches by removing oxygen from colored substances. However, this bleaching is not permanent because the color returns upon exposure to the air and sunlight.


134 SULFUR

EXPERIMENT No. 262 Sulfurous Acid

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

sulfurous acid

FIGURE 18


APPARATUS: Sodium bisulfite, blue litmus paper, vinegar, gas generator bottle, two hole stopper, funnel, delivery tube and sodium carbonate.

PROCEDURE: Place six measures of sodium bisulfite into the gas generator bottle and pour in about a half-inch of water. Insert the stopper with the delivery tube and funnel. Make sure the bottom of the funnel is below the surface of the liquid. Immerse a piece of blue litmus paper in a test tube one-quarter full of water and allow the long stem of the delivery tube to go into this. Now using the funnel add some vinegar to the generator bottle. Note the reaction in the test tube and also the color change of the litmus paper.

SUMMARY: When the vinegar (an acid) was added to the sodium bisulfite, sulfur dioxide gas was liberated and passed into the water with a bubbling effect. Water and soluble sulfur dioxide react to form sulfurous acid which turns blue litmus paper red. 

SULFURIC ACID

Sulfur trioxide reacts readily with water to form sulfuric acid. The two principal processes for making this acid are the Lead Chamber Process and the Contact Process. 

Concentrated sulfuric acid, commonly called oil of vitriol, is a strong and corrosive liquid with oily characteristics. It is the most important of all the acids commercially and industrially not only because of its properties but also because it is inexpensive to make. It has been said that, next to water, it is the liquid most used by chemical industries. Some of its applications are in the refining of petroleum, the manufacture of explosives, dyes, hydrochloric and nitric acids and fertilizers.

EXPERIMENT No 263 How To Make Sulfuric Acid 

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

APPARATUS: Potassium nitrate, sulfur, test tube, blue litmus paper and alcohol lamp or candle. 


LIONEL CHEM-LAB 135

PROCEDURE: Mix one quarter measure of potassium nitrate thoroughly with one quarter measure of sulfur and place in a test tube. Cautiously heat contents and note the white vapors produced. Remove from flame when the vapors stop. Put a cork in the test tube. Add enough water to the test tube to fill it half full. Shake contents and drop in a piece of blue litmus paper. Note the color change.

SUMMARY: Sulfur is oxidized by the oxygen in the potassium nitrate to sulfur trioxide. This compound forms sulfuric acid upon the addition of water.

THE SULFATES

The salts of sulfuric acid are known as sulfates, examples of which are iron sulfate, blue vitriol or copper sulfate, and Epsom salt (magnesium sulfate).

Sodium thiosulfate, otherwise known as sodium hyposulfite, has wide uses in photography. The photographer refers to it as "hypo" and uses it to dissolve from the plate or film any silver salts that have not been affected by light.

EXPERIMENT No. 264 Preparation Or Sodium Sulfate

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

APPARATUS: Sodium chloride (table salt), sodium bisulfate, test tubes.

PROCEDURE: Dissolve two measures of sodium chloride in a test tube half full of water. In another test tube dissolve one measure of sodium bisulfate. Gradually add the sodium bisulfate solution to the sodium chloride solution. Note the white precipitate of sodium sulfate and also the density of the gas which is liberated (hydrogen chloride).

EXPERIMENT No. 265 Reduction Of A Sulfate

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

APPARATUS: Charcoal block, sodium carbonate, sodium bisulfate, alcohol lamp, blowpipe, sulfide test paper and an eye dropper.

PROCEDURE: Make a small indentation in your charcoal block. Place in this a mixture of one measure of sodium bisulfate with an equal amount of sodium carbonate and one drop of water. Light the alcohol lamp and direct the flame at this mixture with the blowpipe. Continue heating until the substance melts. Set aside to cool. Remove the mass and place it on a piece of moistened sulfide test paper. Note the stain on the test paper.

SUMMARY: When the sulfate reacts with carbon, and heat, it is reduced to a sulfide which can be tested by placing it on a moistened piece of sulfide test paper. The lead from the paper reacts with the


136 SULFUR

sulfide to form the black spot of lead sulfide. This is an excellent test for the reduction of a sulfate.

EXPERIMENT No. 266 Strontium Sulfate Precipitate

(CL-66, CL-77)

APPARATUS: Magnesium sulfate, strontium chloride and test tube.

PROCEDURE: Place two measures of magnesium sulfate in a test tube one quarter full of water and shake to dissolve. Put two measures of strontium chloride into another test tube one quarter full of water and again shake to dissolve. Pour the contents of one tube into the other and note the heavy white precipitate. Add a few drops of hydrochloric acid and note the precipitate still remains undissolved.

SUMMARY: These compounds react to form magnesium chloride and insoluble strontium sulfate which appears as a heavy white precipitate. This sulfate along with those of lead and barium are the only sulfates insoluble in water and hydrochloric acid.

EXPERIMENT No. 267 Iodine Test For Sodium Thiosulfate

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

APPARATUS: Sodium thiosulfate, iodine starch test solution, test tubes, hydrochloric acid.

PROCEDURE: Dissolve two measures of sodium thiosulfate in a test tube half full of water. Add five drops of hydrochloric acid. Cautiously heat the solution. When cool, add four drops of iodine starch test solution prepared as explained in Experiment No. 688. Note the blue color formed.

SUMMARY: Sodium thiosulfate when heated with hydrochloric acid liberates sulfur dioxide which turns starch test solution blue.

EXPERIMENT No. 268 Reaction Of Thiosulfates

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

APPARATUS: Dilute hydrochloric acid, sodium thiosulfate, test tube, alcohol lamp or candle.

PROCEDURE: Dissolve two measures of sodium thiosulfate in a test tube half full of water. Add eight drops of hydrochloric acid. Note turbidity. Heat this solution.

SUMMARY: Upon warming, sulfur dioxide is produced. The turbidity of the solution is caused by the separation of sulfur and sulfurous acid.
Go to ContentsLionel Chem-lab Chapter 9    or   Back to the Experiments Page

"The Science Notebook"  Copyright 2008-2017 - Norman Young