Science Notebook - Lionel Chemlab

The Science Notebook
Lionel Chem-Lab - Chapter 25

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 In addition, much of the information contained in this book about chemistry and other subjects is outdated and some of it is inaccurate.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 256 - 282

CHAPTER XXV

FOODS AND HOUSEHOLD CHEMISTRY

Foods supply our bodies with the warmth and energy which keeps us alive, but in order for a food to be so utilized, it must be absorbed into the blood stream in a liquid or semi-liquid condition. The process of digestion takes care of this by changing food solids and liquids into soluble compounds or emulsions.

Very few foods are eaten raw-most of them have to be baked, roasted or boiled to make them taste better and more easily digestible. The process of cooking also destroys any disease-producing bacteria which may be present.

There are three main classes of foods: fats and oils, proteins and carbohydrates. Fats and oils are obtained from fat meat, butter, lard and the oils from nuts and seeds. The process of digestion emulsifies fats and oils.

EXPERIMENT No. 660 How Fatty Acid Is Made From Soap

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

APPARATUS: Sodium bisulfate, test tube, soap, alcohol lamp or candle.

PROCEDURE: Place one measure of soap in a test tube half full of water. Dissolve the soap by shaking the test tube while heating. Add three measures of sodium bisulfate and note the white precipitate. Carefully boil the solution for a few minutes, then set aside to cool. Note how the fatty acid solidifies.

EXPERIMENT No. 661 Detecting Fat In Foods

(CL-66, CL-77)

APPARATUS: Carbon tetrachloride, mortar and pestle, olives, funnel, cotton, and a dish.

PROCEDURE: Place some olives in the mortar and grind thoroughly. Put four measures of olive meat in a test tube adding just enough carbon tetrachloride to cover it, then shake vigorously. Press a piece of absorbent cotton tightly into a funnel, and filter the mixture through it, collecting the filtrate in a dish of water. Allow the carbon tetrachloride to evaporate. Note the film of fat on the surface of the water.

EXPERIMENT No. 662 Fat Solvents

(CL-66, CL-77)

APPARATUS: Carbon tetrachloride, phenolphthalein solution, test tube, butter, glass, alcohol lamp or candle.

256 LIONEL CHEM-LAB 257

PROCEDURE: Dissolve a small piece of butter in a test tube containing a quarter of an inch of carbon tetrachloride. Fill a glass with water and very carefully float two or three drops of the butter solution on the surface of the water. Allow the carbon tetrachloride to evaporate and note that the butter remains on the surface of the water. Place some butter in a test tube containing a spoonful of alcohol and heat very cautiously to dissolve the butter. Keep your face away from the reaction. Allow to cool and note the formation of fat crystals. Put a little butter in a test tube containing some phenolphthalein solution and note whether the butter dissolves. Phenolphthalein solution contains alcohol and thus dissolves fats.

EXPERIMENT No. 663 Determining The Melting Point Of Fat

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

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

PROCEDURE: Place a little butter in your heating spoon and heat slowly. See how quickly the butter melts. Set aside to cool.

SUMMARY: Note that the butter does not solidify immediately.

EXPERIMENT No. 664- Testing A Candle For Stearic Acid

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

APPARATUS: Sodium carbonate, calcium oxide, alcohol lamp or candle, three test tubes.

PROCEDURE: Place two measures of sodium carbonate and two measures of calcium oxide in a test tube half full of water. Prepare sodium hydroxide solution as described in Experiment No. 344. Boil the solution. If a foam appears, an acid is present.

EXPERIMENT N0. 665 Testing Spoiled Butter For Acid

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

APPARATUS: Blue litmus paper, butter and a dish.

PROCEDURE: Place some butter in a dish covering it with a strip of blue litmus paper. Set aside for a few days examining it from time to time. Note any changes in color either on the butter or on the paper.

SUMMARY: In due time the butter decomposes forming a weak acid which turns the blue litmus paper red.

EXPERIMENT No. 666 Soap Made From Fatty Acid

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

APPARATUS: Sodium carbonate, calcium oxide, sodium bisulfate, test tube, soap, alcohol lamp or candle.

PROCEDURE: Place one measure of soap chips in a test tube half full of water. Dissolve the soap by shaking the test tube while heating over a flame. Add three measures of sodium bisulfate. Boil for a minute then set aside until the fatty acid solidifies. Prepare sodium

258 OTHER INDUSTRIES

hydroxide solution as described in Experiment No. 344. Place the fatty acid in a test tube and add one quarter test tube of sodium hydroxide solution. Boil this solution briefly noting that the fatty acid dissolves forming soap.

SUMMARY: When a fatty acid is treated with sodium hydroxide, soap and dissolved glycerine are formed.

EXPERIMENT No. 667 Methyl Amine From Lechithin

(CL-11, CL-22, CL-33, CL-44, CL-S5, CL-66, CL-77)

APPARATUS: Calcium oxide, sodium carbonate, test tube, candle or alcohol lamp and egg yolk.

PROCEDURE: Prepare sodium hydroxide solution as described in Experiment No. 344. Place a few drops of egg yolk in a third test tube and add one inch of sodium hydroxide solution. Shake vigorously, then boil for a short time. Cautiously smell the odor given off.

SUMMARY: Egg yolk contains phosphorous, nitrogen and other compounds. When the yolk is heated with an alkali it forms a volatile material which has a fishy smell. This compound is known as methyl amine.

EXPERIMENT No. 668 Preparing Acrolein

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

APPARATUS: Butter, sodium bisulfate, test tube, alcohol lamp or candle.

PROCEDURE: Heat two measures of sodium bisulfate in a test tube containing a small portion of butter. Remove from flame immediately after the solution reaches the boiling point. Cautiously smell the strong odor given off.

SUMMARY: Butter, when heated, reacts with sodium bisulfate to form acrolein.

EXPERIMENT No. 669 A Simple Test For Butter

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

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

PROCEDURE: Put a small lump of butter in your heating spoon and heat carefully. If it is fresh butter, it will boil and become frothy. Rancid butter sputters and snaps immediately upon heating.

EXPERIMENT No. 670 “Rejuvenating” Rancid Butter

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

APPARATUS: Rancid butter, pan, air pump, cream and a jar.

PROCEDURE: Place some rancid butter in a pan and melt it. Pump air into it until the odor disappears. Place the butter in a jar and add a little milk or cream. Close the mouth of the jar and shake it until

LIONEL CHEM-LAB 259

the butter solidifies. Remove the milk and note that the remaining solid appears to be fresh butter.

PROTEINS

The second main class of foods is the proteins. We have already learned of proteins in our chapter on Nitrogen. These nitrogenous foods contain a number of elements: carbon, nitrogen, oxygen, sulfur, hydrogen, phosphorous, iron, and are found in such foods as egg albumen, lean meat, beans and peas, casein in sour milk, and gluten in flour.

EXPERIMENT No. 671 A Protein Test For Meat

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

APPARATUS: Lean meat, calcium oxide, red litmus paper, alcohol lamp or candle, test tube.

PROCEDURE: Place one measure of calcium oxide in a test tube containing a small piece of lean meat and a few drops of water. Heat carefully noting any odor of ammonia. Drop a piece of moistened red litmus paper into the test tube.

SUMMARY: When heated with calcium oxide, the nitrogen from the nitrogenous lean meat decomposes into ammonia gas which indicates the presence of protein. This reacts with the water to form ammonium hydroxide which produces a color change on the litmus paper.

EXPERIMENT No. 672 Protein Test For Milk

(CL-11, CL-22, CL-33, CL-44, CL-55, CL-G6, CL-77)

APPARATUS: Milk, calcium oxide, test tube, candle or alcohol lamp, red litmus paper.

PROCEDURE: Place one measure of calcium oxide in a test tube containing five drops of milk. Heat carefully noting any odor of ammonia. Drop a piece of moistened red litmus paper into the test tube. This reaction is the same as explained in the preceding experiment.

EXPERIMENT No. 673 Eggs Containing Protein

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

Repeat Experiment No. 671 substituting some egg-white for the meat.

EXPERIMENT No. 674 A Protein Test On Potato Skin

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

Repeat Experiment N0. 671 substituting potato skin for meat.

EXPERIMENT No. 675 Hair Is A Protein

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

Repeat Experiment No. 671 substituting a strand of hair for the meat.

260 FOODS AND HOUSEHOLD CHEMISTRY

EXPERIMENT No. 676 Another Form Of Protein

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

Repeat Experiment No. 671 substituting fingernail clippings for the meat.

EXPERIMENT No. 677 Testing Proteins For Carbon

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

APPARATUS: Test tube, candle or alcohol lamp, egg-white.

PROCEDURE: Place a little egg white in a test tube and heat carefully. Cease heating when the vapors stop rising. The black residue is carbon.

EXPERIMENT No. 678 Testing Hair For Sulfur

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

APPARATUS: Hair, calcium oxide, sodium carbonate, tartaric acid, sulfide test paper, test tube, alcohol lamp or candle.

PROCEDURE: Place a strand of hair in a test tube one quarter full of water. Add one measure of calcium oxide and the same of sodium carbonate. Heat to boiling for several minutes, then set the tube aside to cool. Add a few measures of tartaric acid and reheat. Expose a moistened strip of sulfide test paper to the mouth of the test tube and note the black stain indicating the presence of hydrogen sulfide.

EXPERIMENT No. 679 Testing Proteins For Sulfur

(CL-66, CL-77)

APPARATUS: White of egg, calcium oxide, two test tubes, tartaric acid, sulfide test paper, candle or alcohol lamp, mortar and pestle.

PROCEDURE: Place enough calcium oxide and egg-white in the mortar to make a ball of dough about the size of a marble. Put this into a test tube and heat carefully. Note the color change and the odor. Allow the tube to cool, then fill it one quarter full of water. Shake and pour the brown liquid into another test tube. Add two measures of tartaric acid and heat to the boiling point. Remove from flame and again note the odor. Insert a moistened piece of sulfide test paper into the test tube.

SUMMARY: In the first reaction, calcium oxide decomposes the protein which reacts with tartaric acid to form hydrogen sulfide. The hydrogen sulfide turns sulfide test paper black.

EXPERIMENT No. 680 How To Make Casein

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

APPARATUS: Skimmed milk, sodium bisulfate and two test tubes.

PROCEDURE: Mix in a test tube one part of skimmed milk to four parts of water. Dissolve five measures of sodium bisulfate in another test tube half full of water. Pour this solution a little at a time into

LIONEL CHEM-LAB 261

the test tube containing the milk. Shake the test tube well after each addition. Note the precipitate which appears in the milk.

SUMMARY: This precipitate is a form of protein called casein. It is used in cheese manufacturing as a base and is also used as an adhesive.

EXPERIMENT No. 681 Effect Of Heat On Egg-white

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

APPARATUS: Egg-white, test tube and candle or alcohol lamp.

PROCEDURE: Put a few drops of egg-white in a test tube half full of water. Shake well, then heat the solution slowly. Note the cloudy formation in the test tube. Heat causes the egg-white to coagulate.

EXPERIMENT No. 682 Separating Gluten From Wheat Flour

(CL-66, CL-77)

APPARATUS: Flour, piece of cloth, mortar and pestle.

PROCEDURE: Place two teaspoonfuls of flour in the mortar and add enough water to make a stiff dough. Wrap the dough in a piece of white cotton cloth and work it with your fingers under a stream of running water. Continue until all the starch is removed.

SUMMARY: The substance remaining in the cloth after all the starch has been removed from the flour is gluten, a protein.

CARBOHYDRATES

The carbohydrates includes starch and the sugars. We have already studied starch and sugar to some extent in other chapters of our book. Corn and potatoes furnish large quantities of starch as well as rice, flour and cereals. Also we have learned that there are several different kinds of sugar, principally cane sugar and beet sugar.

EXPERIMENT No. 683 How Starch Is Composed

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

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

PROCEDURE: Place four measures of starch in a dry test tube and heat carefully. Note the moisture that is given off. Continue heating and note the various color changes the starch passes through. Discontinue heating when the mass becomes black and examine it. The basic composition of starch is carbon.

EXPERIMENT No. 684 Extracting Starch From Flour

(CL-66, CL-77)

APPARATUS: Teaspoon, mortar and pestle, wheat Hour, a glass tumbler.

PROCEDURE: Mix four teaspoonfuls of wheat flour in the mortar

262 FOODS AND HOUSEHOLD CHEMISTRY

with enough water to make a ball of stiff dough. Hold a small ball of the dough in a glass of water and work it with your fingers to squeeze out the starch. Repeat the procedure with another piece of dough until no more starch can be extracted. Note the starch which gradually collects at the bottom of the glass.

EXPERIMENT No. 685 Extract Starch From Potatoes

(GL-66, CL-77)

APPARATUS: Raw potato, mortar and pestle, glass tumbler and a piece of coarse cloth.

PROCEDURE: Place a few slices of raw potato in the mortar and add a little water. Grind this into a pulp, add more water and continue stirring. Strain this through the cloth, collecting the liquid in a tumbler. Fill the tumbler half way with water, stir and set aside. Note how the starch eventually settles out of the solution.

EXPERIMENT No. 686 Starch From Corn

(CL-66, CL-77)

APPARATUS: Uncooked kernels of corn, mortar and pestle, coarse cloth, tumbler.

PROCEDURE: Place a few uncooked kernels of corn in the mortar, add a little water and grind to a paste. Strain the corn paste through the coarse cloth into a tumbler. Fill the tumbler half full of water, stir thoroughly and set aside. Note how the starch gradually settles at the bottom of the glass.

EXPERIMENT No. 687 How To Dissolve Starch

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

APPARATUS: Starch, candle or alcohol lamp, glass tumbler, alcohol lamp or candle.

PROCEDURE: Place two measures of starch in a tumbler with half an inch of cold water and mix thoroughly. Add some boiling water, and heat for a minute or two. Note that the starch dissolves.

EXPERIMENT No. 688 Preparing A Starch Test Solution

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

APPARATUS: Ferric ammonium sulfate, sodium bisulfate, sodium iodide solution, test tube.

PROCEDURE: Prepare a starch test solution by placing one measure of ferric ammonium sulfate and one measure of sodium bisulfate in a test tube three quarters full of water. Add ten drops of sodium iodide solution and shake vigorously. Set this starch test solution aside for use in future experiments.

EXPERIMENT No. 689 Testing For The Presence Of Starch In Corn

(GL-66. CL-77)

LIONEL CHEM-LAB 263

APPARATUS: A few kernels of corn, two test tubes, mortar and pestle, candle or alcohol lamp, starch test solution.

PROCEDURE: Grind two kernels of corn in your mortar. Place one measure of the powdered corn into a test tube containing one half inch of water. Heat to boiling, then set tube aside to cool completely. Pour into this cold solution three drops of starch test preparation. Note the blue color. The blue color is proof that corn contains starch.

EXPERIMENT No. 690 How To Test For Starch In Flour

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

APPARATUS: Flour, two test tubes, candle or alcohol lamp, starch test solution.

PROCEDURE: Place one measure of flour in a test tube half full of water and heat to boiling. Allow contents to cool. Pour in three drops of the starch test solution made in Experiment No. 688.

SUMMARY: Note the blue color proving that flour contains starch.

EXPERIMENT No. 691 How Rice Is Tested For Starch

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

APPARATUS: Rice, test tube, candle or alcohol lamp, starch test solution.

PROCEDURE: Place one measure of rice in a test tube half full of water. Heat to boiling for a few minutes. Allow contents to coll completely. Pour in three drops of starch test solution. Note the blue color. This test proves that starch is present in rice.

EXPERIMENT No. 692 Proving That Oatmeal Contains Starch

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

APPARATUS: Oatmeal, two test tubes, candle or alcohol lamp, starch test solution.

PROCEDURE: Put several oatmeal Hakes into a test tube one quarter filled with water and heat to boiling. Set test tube aside to cool thoroughly. Add a few drops of the starch test solution. This blue color indicates the presence of starch in the oatmeal.

EXPERIMENT No. 693 How To Test Corn Flakes Fon Starch

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

APPARATUS: Corn flakes, two test tubes, candle or alcohol lamp, starch test solution.

PROCEDURE: Place one measure of corn flakes in a test tube one quarter full of water. Heat to boiling then set tube aside to cool completely. Add three drops of the starch test solution. The blue color is proof that starch is present in corn flakes.

264 FOODS AND HOUSEHOLD CHEMISTRY

EXPERIMENT No. 694 Testing Wheat Cereals For Starch

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

APPARATUS: Wheat cereal, two test tubes, candle or alcohol lamp, starch test solution.

PROCEDURE: Boil a solution consisting of one measure of wheat cereal in a test tube one quarter full of water. Set test tube aside to cool. Add three drops of starch preparation to the cold solution. Note the blue color proving that wheat cereals contain starch.

EXPERIMENT No. 695 A Starch Test For Ripe Fruit

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

APPARATUS: Ripe fruit (apple), starch test solution.

PROCEDURE: Apply some starch test solution to a slice of ripe apple and note that the color does not change. The test is negative because the starch in the apple has been converted into sugar.

EXPERIMENT No. 696 A Starch Test For Green Fruit

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

APPARATUS: A green apple, starch test solution.

PROCEDURE: Apply some starch test solution to a slice of green apple. Note, in due time, the appearance of the characteristic blue color proving that a green apple contains starch.

EXPERIMENT No. 697 Starch In Potatoes

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

APPARATUS: Potato, candle or alcohol lamp, starch test solution.

PROCEDURE: Place a small slice of raw potato in a test tube one third filled with water. Heat to boiling. Allow the contents to cool thoroughly. Pour into this cold solution three drops of the starch test solution. Note the blue color which indicates the presence of starch.

EXPERIMENT No. 698 Burning Starch Powder

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

APPARATUS: Starch, glass tube, alcohol lamp or candle.

PROCEDURE: Place one half measure of starch powder in a section of glass tubing. Light the alcohol lamp and blow the starch powder into the flame. Note the color of the flame and also the combustible properties of starch.

EXPERIMENT No. 699 How Dextrine Is Formed

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

APPARATUS: Dry starch, test tube, candle or alcohol lamp.

PROCEDURE: Put five measures of dry starch in a test tube and heat carefully. Note the moisture given off. Continue heating until a brown

LIONEL CHEM-LAB 265

color appears. Cautiously smell the odor coming from the tube and examine the material inside the test tube. The brown residue is dextrine.

EXPERIMENT No. 700 Preparing A Dextrine Paste

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

APPARATUS: Dry starch, test tube, candle or alcohol lamp, paper.

PROCEDURE: Prepare some dextrine as described in the preceding experiment. Add three drops of water. Note that the dextrine dissolves in cold water. Apply some of this to a piece of paper and note how it adheres.

EXPERIMENT No. 701 A Test For Dextrine

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

APPARATUS: Dry starch, test tube, starch test solution, candle or alcohol lamp.

PROCEDURE: Prepare some dextrine as described in Experiment No. 699. Pour a few drops of water into the test tube and shake well. Then fill the test tube half way with water and add a few drops of starch test solution. Note the color reaction. If a purple, red or brown color sets in you have heated the dextrine too long.

EXPERIMENT No. 702 The Composition Of Sugar

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

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

PROCEDURE: Heat twelve measures of sugar in your heating spoon. Note the changes which the sugar undergoes as the heating continues. Discontinue heating when the contents of the spoon turn black. You have now converted sugar into carbon.

EXPERIMENT No. 703 Preparation Of Beet Sugar

(CL-66, CL-77)

APPARATUS: Raw sugar beets, mortar and pestle, funnel, filter paper, pan, alcohol lamp or candle and test tube.

PROCEDURE: Place a few thin slices of raw sugar beet in the mortar and add a little water. Grind this to a pulp and then pass it through a filter, collecting the clear liquid in a test tube. Taste the liquid and note that it has a sweet taste. Pour the liquid into a pan and boil it until it becomes sirupy. Set aside to cool and note whether or not the sugar crystallizes. A saturated solution will cause the sugar to crystallize.

EXPERIMENT No. 704 Combustible Sugar

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

APPARATUS: Tin pan, lump of sugar, alcohol lamp or candle.

266 FOODS AND HOUSEHOLD CHEMISTRY

PROCEDURE: Put a lump of sugar in a tin pan and hold the cover over a flame. Note the rapidity with which the sugar burns.

SUMMARY: Heat caused the sugar to decompose into carbon and water.

EXPERIMENT No. 705 Luminescence Of Sugar

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

APPARATUS: Two lumps of sugar.

PROCEDURE: Rub two lumps of sugar against each other in a totally dark room.

SUMMARY: Note the faint flashes of light.

EXPERIMENT No. 706 How To Prepare Caramel

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

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

PROCEDURE: Heat twelve measures of sugar in a test tube. Note the moisture on the inner walls of the test tube. Discontinue heating when the sugar turns brown. (Do not burn). Note the pleasant caramel odor.

EXPERIMENT No. 707 How Starch Is Converted By Digestion

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

APPARATUS: Starch test solution, test tubes, candle or alcohol lamp.

PROCEDURE: Place three measures of starch in a test tube and add a little water to form a paste. Add half a test tube of boiling water and boil the solution for a few minutes. Place some of this in a test tube containing a little saliva and warm over a flame for a few minutes. Allow the mixture to cool. To a few drops of the mixture add a little starch test solution and note whether a blue color appears. Reheat the saliva preparation in the same manner as before and again cool. Again test a few drops with starch test solution. Note whether the reddish-brown color of dextrine appears. Reheat the saliva preparation again and cool. Test a few drops with starch test solution. Continue the heating, cooling and testing processes until the starch test preparation produces no color reaction.

SUMMARY: This illustrates how the digestive process operates on food. In this case, the saliva converts the starch to a sugar which can be utilized by our bodies.

EXPERIMENT No. 708 Making Glucose By Hydrolysis

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

APPARATUS: Starch, test tube and alcohol lamp or candle, sodium bisulfate.

PROCEDURE: Place ten measures of starch and three measures of sodium bisulfate in another test tube full of water. Carefully boil the solution for about ten minutes. Allow the contents to cool completely. Put a few drops of this cold solution into another test tube and add

LIONEL CHEM-LAB 267

two or three drops of starch solution. Note whether a blue color results. Continue heating the solution until no blue color forms when treated with then starch test solution. Make sure that the solution is cold before applying the test. When no more starch is present pour the liquid into a dish and set aside until the glucose crystallizes. Starch has been converted into glucose by the process known as hydrolysis.

EXPERIMENT No. 709 How Apple Jelly Is Made

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

APPARATUS: Crab apples, cheesecloth, pan and alcohol (drug store).

PROCEDURE: Place five crab apples in a cloth and crush them, catching the juice in a pan. Pass this juice through cheese cloth a few times in order to strain it thoroughly. Pour one quarter test tube full of juice in a test tube containing five drops of alcohol. Note the cloudy gelatinous precipitate. This gelatinous precipitate is known as pectin used in the manufacture of jams.

CAUTION: Under no circumstances should any of the foods, on which you have been conducting chemical tests, be taken into the mouth or eaten.

EXPERIMENT No. 710 The Chemistry Of Currant Jelly

(CL-66, CL-77)

APPARATUS: Red currants, mortar and pestle, cheesecloth, test tube, alcohol (drug store), glass container, cup.

PROCEDURE: Place a cupful of red currants in the mortar and crush them thoroughly. Strain this through the cheesecloth allowing the juice to pass into the container. Mix one inch of juice with an equal amount of water in a test tube. Add one half test tube full of alcohol and note the precipitate. The precipitate is also pectin, the gelatinous base of jams and jellies.

EXPERIMENT No. 711 Another Experiment With Sugar

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

APPARATUS: Lump of sugar, cigarette ashes, test tube holder, candle or alcohol lamp.

PROCEDURE: Try to ignite a lump of sugar by holding it over a flame with a test tube holder. Dip the end of the sugar into cigarette ashes so that some of the ashes adhere to the surface of the sugar. Place the sugar over the flame again and note how more easily the sugar burns.

SUMMARY: Cigarette ash aids the combustion of sugar by lowering its 'kindling point.

MILK

Very few of our common foods contain some of each of our three main types of food, that is, carbohydrates, proteins and fats. For example, meats and eggs both contain fat and protein, but no carbohydrate. Bread, on the

268 FOODS AND HOUSEHOLD CHEMISTRY

other hand, is largely carbohydrate with a little protein. By adding butter to our bread, we of course add fat so that the two together make quite a complete food.

Of the many common foods, authorities agree that milk is practically the only one which contains all the nutrients in about the proportion they are needed in the human body. Milk has the following composition: Water 88 per cent, milk sugar 4 to 5 per cent, fat 3 to 6 per cent, protein 3 to 4 per cent, and mineral ash three quarters of one per cent.

EXPERIMENT No. 712 Making Condensed Milk

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

APPARATUS: Milk, pan, sugar and cup.

PROCEDURE: Carefully evaporate a cup of milk by heating. Stir carefully to prevent sticking as the milk becomes thicker. Add a pinch of sugar when the milk has reached the desired thickness and stop heating. Condensed milk has the advantage over ordinary milk in that it can be stored in vacuum sealed cans for a long period without spoiling.

EXPERIMENT No. 713 Making Powdered Milk

(CL-66, CL-77)

APPARATUS: Milk, double boiler, mortar and pestle, cup.

PROCEDURE: Pour a cupful of milk into a double boiler and fill the bottom part half full of Water. Boil for an hour, stirring the milk occasionally and continually adding more water to the bottom part of the boiler as fast as it boils away. When the milk has dried completely, transfer it to the mortar and grind thoroughly with the pestle.

SUMMARY: This powdered product has many useful purposes, such as, in manufacturing plastics and glues. By adding water to the powder, the milk is restored nearly to its original condition.

EXPERIMENT No. 714 How To Test Milk

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

APPARATUS: Sodium bicarbonate, milk, test tube, filter paper and measuring spoon.

PROCEDURE: Dissolve two measures of sodium bicarbonate in a test tube three quarters full of milk. Insert a strip of filter paper and set aside for twelve hours. Note any color change on the paper. If a color appears then the milk has been adulterated.

EXPERIMENT No. 715 Foaming Matter In Milk

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

APPARATUS: Milk, funnel, filter paper.

PROCEDURE: Pass some well-shaken milk through the filter and note whether there are any particles left on the paper.

SUMMARY: Undissolved foreign matter is often detected by this method by your city health inspector whenever a milk analysis is made.

LIONEL CHEM-LAB 269

FERMENTATION

Fermentation is a chemical change induced by the action of an organic body such as yeast, an enzyme or bacterium. Vinegar is a common example of a product made by fermentation. Sour milk, rancid butter and the decay of foods are all examples of fermentation caused by plant organisms. Other examples are the production of grain alcohol, beer, wine and hard cider. Thus, we see that certain kinds of bacteria, mold and mildew, destroy food by decay and rot. Other types of fermentation, such as that induced by yeast and enzymes, are put to good use in the making of bread and alcoholic beverages.

EXPERIMENT No. 716 How Milk Ferments

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

APPARATUS: Fresh milk and a tumbler.

PROCEDURE: Fill a tumbler half full, of fresh milk and set aside in a warm place. Note the changes which take place in a day or two.

SUMMARY: When milk is exposed to air over a period of time, fermentation occurs and an acid is formed called lactic acid which curdles the milk.

EXPERIMENT No. 717 How Sugar Ferments

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

APPARATUS: Sugar, two tumblers and yeast.

PROCEDURE: Dissolve two teaspoonfuls of sugar in a tumbler half full of water. Put a small piece of yeast in another tumbler and add enough water to form a thin paste. Pour this into the sugar solution and set aside in a warm place. Note the reaction which takes place in a few hours. Dip a lighted match into the mouth of the tumbler and note that the flame is extinguished.

SUMMARY: During the process of fermentation, one of the products formed is carbon dioxide gas. As we learned in our study of carbon dioxide, it does not support combustion, thus the lighted match goes out.

EXPERIMENT No. 718 Formation Of Mold

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

APPARATUS: Starch, small pan and tumbler.

PROCEDURE: Pour a little cold water into a pan containing a teaspoonful of starch. Stir well and then add a tumbler full of boiling water. Heat to boiling until a paste forms. Put this paste into a tumbler and set aside in a warm place for a few days. Note from time to time the formation and growth of mold.

EXPERIMENT No. 719 Making Alcohol From Sugar

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

270 FOODS AND HOUSEHOLD CHEMISTRY

APPARATUS: Sugar, two tumblers, yeast and vinegar, teaspoon.

PROCEDURE: Place a teaspoonful of sugar in a tumbler one quarter filled with water and shake to dissolve. Put a quarter cake of yeast in another tumbler and add enough water to form a paste. Pour this into the sugar solution and set aside in a warm place for five or six days. Add a few drops of vinegar when the bubbling reaction has ceased. Set aside for a few more days and then taste.

SUMMARY: The solution will have a vinegar taste. The bubbles of gas which were formed were carbon dioxide. Alcohol was also formed in the solution. This demonstrates the action of the enzymes secreted by the yeast plants. The enzyme acts like a catalytic agent in changing the sugar into alcohol and carbon dioxide.

EXPERIMENT No. 720 How Cider Is Converted Into Vinegar

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

APPARATUS: Cider, yeast, cardboard, vinegar, tumbler.

PROCEDURE: Place a small piece of yeast in a tumbler filled with cider and set aside covered with a piece of cardboard or paper. Taste this from day to day and when the bubbling reaction ceases pour in two or three drops of vinegar. Set aside and taste after a few days. After a few days, the solution will have a vinegar taste.

OTHER EXPERIMENTS WITH FOODS

EXPERIMENT No. 721 How To Make Baking Powder

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

APPARATUS: Tartaric acid, sodium bicarbonate and test tubes.

PROCEDURE: Mix well in a test tube eight measures of tartaric acid and five measures of sodium bicarbonate. Slowly fill the tube half full of water. Note how the solution effervesces.

SUMMARY: Baking powder is formed when sodium bicarbonate is mixed with tartaric acid. If water is added to the mixture, an effervescent reaction takes place liberating carbon dioxide.

EXPERIMENT No. 722 Test In Baking Powder For Starch

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

APPARATUS: Starch test solution, alcohol lamp or candle, baking powder, two test tubes.

PROCEDURE: Prepare some starch test solution. Add one measure of baking powder to a test tube half full of water and heat to boiling. Allow to cool completely, then add one drop of the starch test solution. Note whether the characteristic blue color appears. If blue color appears then starch is present.

EXPERIMENT No. 723 Testing Baking Powder For Alum

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

LIONEL CHEM-LAB 271

APPARATUS: Logwood, baking powder, vinegar, funnel, filter paper, three test tubes and alcohol lamp or candle.

PROCEDURE: Place a measure of logwood in a test tube three quarters full of water and heat to boiling. Filter the liquid into another test tube. Put four measures of baking powder in a second test tube three fourths full of water. Note the bubbling reaction. Add four drops of vinegar and three drops of logwood when the bubbling has stopped. If a violet color forms, alum is present.

EXPERIMENT No. 724 How To Tell If An Egg Is Fresh

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

APPARATUS: Salt, a wide mouthed glass jar, an egg and a teaspoon.

PROCEDURE: Put ten spoonfuls of salt in a glass jar containing one pint of water and stir to dissolve. Place the egg in the salt solution. Note whether the egg sinks or not. If it sinks, the egg is fresh.

EXPERIMENT No. 725 Another Test To Determine The Freshness Of Eggs

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

APPARATUS: Egg.

PROCEDURE: Shake the egg vigorously next to your ear. Note whether any sound comes from the egg. If you cannot detect any sound, the egg is a fresh one.

EXPERIMENT No. 726 How Eggs Are Candled

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

APPARATUS: Egg and candle.

PROCEDURE: Hold an egg in front of a candle flame, in a dark room. Note whether the egg is clear or spotted. If spots are present the egg is not fresh.

EXPERIMENT No. 727 How Ground Meat Is Tested

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

APPARATUS: Starch test solution, ground meat, alcohol lamp or candle and two test tubes.

PROCEDURE: Prepare some starch test solution. Place a small piece of meat in a test tube half full of water and heat to boiling. Allow to cool completely, then add a few drops of starch test solution. Note any blue coloration indicating that the meat has been adulterated with starch.

EXPERIMENT No. 728 How Honey Is Tested For Purity

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

APPARATUS: Tannic acid, honey, calcium oxide, test tubes, alcohol lamp or candle, and two test tubes.

272 FOODS AND HOUSEHOLD CHEMISTRY

PROCEDURE: Dissolve one measure of tannic acid in a test tube half full of water. Dissolve one measure of calcium oxide in another test tube half full of water. Add six drops of honey to the tannic acid solution and heat the solution to boiling. Look for a gelatinous precipitate. Cool test tube, then add ten drops of calcium oxide solution. Reheat test tube and cautiously waft towards you some of the vapors given off by the solution. If the odor of the vapor given off resembles the odor of ammonia, then the honey has been adulterated.

EXPERIMENT No. 729 Testing Honey

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

APPARATUS: Tannic acid, honey, two test tubes, alcohol lamp or candle.

PROCEDURE: Place six drops of honey in a test tube. Dissolve two measures of tannic acid in a second test tube half full of water. Add this solution to the honey. Heat the mixture and look for a gelatinous precipitate. If a gelatine forms, the honey has been adulterated.

EXPERIMENT No. 730 How Honey Is Tested For Alteration With Gelatine

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

APPARATUS: Honey and test tube.

PROCEDURE: Dissolve a little honey in a test tube one quarter full of water. Heat until the honey thickens. Allow to cool and note whether the honey remains thick. If it forms a gelatine, then the honey is adulterated.

EXPERIMENT No. 731 How Rye Flour Is Tested

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

APPARATUS: Two flat pieces of glass, rye flour.

PROCEDURE: Place three measures of rye flour on one piece of glass and pour enough water over it to encircle the flour. Spread the mixture and press the other glass over it. Slide the glasses back and forth and look for white spots. If white spots appear, the rye Hour has been adulterated-probably with wheat flour.

EXPERIMENT No. 732 Testing Flour For Bleaching

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

APPARATUS: Flour, glass, non-leaded gasoline (colorless), teaspoon.

PROCEDURE: Put two teaspoonfuls of flour in a glass half filled with clear gasoline. Stir for a while, then set aside. Note the color of the gasoline after the flour has settled out. If no color appears, then the flour has been bleached.

EXPERIMENT No. 733 How Bread Is Tested For Alum

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

LIONEL CHEM-LAB 273

APPARATUS: Logwood, test tube, funnel, filter paper, alcohol lamp or candle, bread.

PROCEDURE: Place one measure of logwood in a test tube half full of water and heat until a dark red color is obtained. Pass this through a filter, collecting the clear solution in another test tube. Pour a few drops of the solution on a piece of bread and set aside for a few hours. Note any color changes. A reddish-brown color indicates that the bread is pure and does not contain alum.

EXPERIMENT No. 734 Testing Wheat Flour For Adulteration
(CL-55, CL-66, CL-77)

APPARATUS: Wheat flour, glycerine, candle or alcohol lamp.

PROCEDURE: Pour three drops of glycerine in a test tube containing one measure of wheat Hour. Heat to boiling for a few minutes. Note whether there is any odor to the reaction. If cornmeal is present in the flour, an odor similar to that of popcorn is produced.

EXPERIMENT No. 735 How Olive Oil Is Tested

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

APPARATUS: Olive oil, sodium bisulfate and test tube.

PROCEDURE: Place four measures of sodium bisulfate in a test tube containing half an inch of olive oil and shake well for several minutes. The oil is pure olive oil, if a reddish-brown color appears, otherwise it may have been adulterated with another oil such as cottonseed oil.

EXPERIMENT No. 736 How To Bleach Meat

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

APPARATUS: Chopped meat, hydrogen peroxide (from your drug store), and a test tube.

PROCEDURE: Place a small piece of raw chopped meat in a test tube containing half an inch of water. Add three drops of hydrogen peroxide and set the meat aside.

SUMMARY: Note that the meat eventually loses its color because it has been bleached (oxidized) by hydrogen peroxide.

EXPERIMENT No. 737 How Spices Can Be Tested

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

APPARATUS: Starch test solution, cloves, two test tubes, alcohol lamp or candle, eye dropper, test tube holder.

PROCEDURE: Prepare some starch test solution as described in Exp. No. 688. Place three measures of cloves in a test tube one half full of water and heat to boiling. Allow to cool completely then add three drops of starch test solution. Note the presence of a blue color if starch is present.

EXPERIMENT No. 738 How Coffee Can Be Tested

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

274 FOODS AND HOUSEHOLD CHEMISTRY

APPARATUS: Ground coffee, glass and stirring rod.

PROCEDURE: Put a teaspoonful of ground coffee in a glass of water and stir for a few minutes noting whether any of the particles settle to the bottom. Apply the starch test and note whether there is any change in the color of the liquid. Starch should not be present in pure coffee.

EXPERIMENT No. 739 How Vinegar Is Tested

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

APPARATUS: Vinegar, teacup, pot, lump of sugar, and a test tube.

PROCEDURE: Boil some water in any household pot. Float a cup containing a test tube measure of vinegar on the boiling water. Continue boiling until the vinegar is reduced to half the original amount. Add to this a small lump of sugar and continue heating until the vinegar evaporates completely. If the sugar turns black, the vinegar is impure and the presence of sulfuric acid is indicated.

EXPERIMENT No. 740 How Lemon Extract Is Tested

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

APPARATUS: Lemon extract and a test tube.

PROCEDURE: Pour a small quantity of lemon extract into a test tube one half filled with water and shake vigorously.

SUMMARY: If the solution becomes cloudy the extract contains lemon. If it remains clear, the lemon flavor is artificial.

EXPERIMENT No. 741 Testing Mustard

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

APPARATUS: Prepared mustard, watch glass, alcohol, filter paper, boric acid, hydrochloric acid and sodium carbonate.

PROCEDURE: Place two measures of prepared mustard on the watch glass and set aside to dry. When the mustard is dry pour over it two or three drops of alcohol. Place a strip of filter paper in the mixture and leave it until the liquid has evaporated. Set the paper aside to dry. Put one measure of boric acid into a test tube one half full of water and shake to dissolve. Pour into the test tube a few drops of hydrochloric acid then dampen the prepared filter paper and set it aside to dry. Note any color change. Place one measure of sodium carbonate in another test tube half full of water and shake to dissolve. Place two drops of sodium carbonate solution on the paper and again set it aside to dry. Note any color change. If the filter paper turns red then the mustard contains turmeric.

EXPERIMENT No. 742 Testing Canned Foods For Iron

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

APPARATUS: Canned fruit juice, tannic acid and two test tubes.

PROCEDURE: Dissolve a measure of tannic acid in a test tube one

LIONEL CHEM-LAB 275

quarter full of water. Place five drops of tannic acid solution in a test tube containing a small quantity of canned fruit juice. If the contents of this tube become black, the fruit juice contains iron.

EXPERIMENT No. 743 Testing Canned Foods For Copper

(CL-66, CL-77)

APPARATUS: Sodium bisulfate, canned food, cup, mortar and pestle, pan, bright steel nail.

PROCEDURE: Place some canned peas in the mortar and grind thoroughly. Put a spoonful of this pulp into a cup containing three spoonfuls of water and two measures of sodium bisulfate. Heat the cup by placing it in a pan of boiling water. Place a smooth steel nail in the cup and allow the boiling to continue for twenty minutes. Stir from time to time noting whether the nail becomes a reddish color.

SUMMARY: Since the position of iron is higher than copper in the electro-chemical series, iron has the power to displace copper from its solution.

EXPERIMENT No. 744 Neutralizing Acids In Foods

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

APPARATUS: Lemon, sodium carbonate, two t€St tubes, blue litmus paper.

PROCEDURE: Place five measures of sodium carbonate in a test tube half full of water. Pour this solution a drop at a time into another test tube one half full of lemon juice. Note the effervescent reaction which indicates the formation of carbon dioxide gas. Continue to add the carbonate solution until the liquid fails to turn blue litmus paper red.

EXPERIMENT No. 745 How To Restore Color To Discolored Meat

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

APPARATUS: Ground meat, sodium bisulfite, test tube.

PROCEDURE: Allow the meat to darken by exposing it to air for two or three hours. Mix two measures of sodium bisulfite and a small portion of the discolored meat in a test tube containing one half inch of water. Note that the original color will return to the meat.

EXPERIMENT No. 746 Testing Vanilla Extract For Alkali

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

APPARATUS: Vanilla extract and a test tube.

PROCEDURE: Pour about one inch of water into a test tube containing one half inch of vanilla extract. Shake well and note whether a reddish-brown precipitate occurs. If this precipitate forms no alkali is present.

EXPERIMENT No. 747 Testing Mustard For Starch Adulteration

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

276 FOODS AND HOUSEHOLD CHEMISTRY

APPARATUS: Prepared mustard, two test tubes, ferric ammonium sulfate, sodium bisulfate, sodium iodide solution and candle or alcohol lamp, test tube holder.

PROCEDURE: Prepare a starch test solution as described in Experiment No. 688. Place a teaspoonful of prepared mustard in a test tube half full of water and heat to boiling for ten minutes. Allow to cool completely, then add three drops of starch test solution. If the solution becomes blue the mustard has been adulterated.

EXPERIMENT No. 748 Citric Acid Made From Calcium Citrate

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

APPARATUS: Lemon, calcium carbonate, sodium bisulfate, candle or alcohol lamp, filter paper, a funnel, and test tubes.

PROCEDURE: Add some calcium carbonate, a little at a time into a test tube containing a little lemon juice. Continue until the bubbling reaction stops. Set the tube aside until the precipitate settles and then pour off the clear solution. Add half a test tube of water to the precipitate. Allow the precipitate to settle and once again pour off the clear fluid. Add two measures of sodium bisulfate and one half inch of water to the precipitate. Heat for a few minutes and note the new precipitate. Filter the solution and collect the liquid in another test tube. Evaporate the liquid and examine the residue.

SUMMARY: Sodium bisulfate reacts with calcium citrate to form citric acid. This is the residue which is formed after the evaporation of the filtered liquid.

EXPERIMENT No. 749 Calcium Citrate Made From Lemon Juice

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

APPARATUS: Lemon, calcium carbonate and test tube.

PROCEDURE: Place some calcium carbonate, a little at a time in a test tube containing a small quantity of juice. Continue until the bubbling reaction stops. Set the tube aside until the precipitate settles and then pour off the clear solution. Add half a tube of water. Allow the precipitate to settle and once again pour off the clear fluid.

SUMMARY: The precipitate is calcium citrate. The lemon which is a weak acid reacts with calcium carbonate to form calcium citrate and carbon dioxide gas.

MISCELLANEOUS HOME CHEMISTRY

EXPERIMENT No. 750 How To Make Silver Polish

(CL-77)

APPARATUS: Calcium carbonate, ammonium hydroxide, mortar and pestle.

PROCEDURE: Put a few measures of calcium carbonate and some

LIONEL CHEM-LAB 277

drops of ammonium hydroxide into the mortar. Grind thoroughly until a paste is formed. This polish may be used for cleaning silver.

EXPERIMENT No. 751 Cleaning Jewelry

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

APPARATUS: Soap, rouge, dirty jewelry, glass and clean cloth.

PROCEDURE: Mix thoroughly four measures of rouge with a quarter of a glass of water, then add enough soap to make a thin paste. This paste may be used to polish jewelry.

EXPERIMENT No. 752 Cleaning Silverware With Sodium Thiosulfate

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

APPARATUS: Sodium thiosulfate, test tube and soft cloth.

PROCEDURE: Place four measures of sodium thiosulfate in a test tube half full of water and shake well. Dampen the cloth with this solution and rub it on a piece of tarnished silverware. Note how it removes the tarnish. Silver sulfide can be removed from silver by cleaning it with sodium thiosulfate solution.

EXPERIMENT No. 753 How Silver Polish Is Tested For Ammonia

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

APPARATUS: Silver polish, calcium oxide, test tube, alcohol lamp or candle.

PROCEDURE: Pour a little of the silver polish in a test tube containing one measure of calcium oxide and a few drops of water. Heat carefully. Remove tube from flame occasionally and sniff the contents cautiously to detect any odor. If ammonia is present then its characteristic odor will be noticeable.

EXPERIMENT No. 754 Cleaning Silvervvare

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

APPARATUS: Tarnished silverware, aluminum pot and salt.

PROCEDURE: Put the tarnished silver in the aluminum pot containing one quart of water and a teaspoonful of salt. Heat to boiling point and note that the tarnish is removed from the silver in a short time. Discontinue heating and remove the silver from the pan or the aluminum will become corroded.

EXPERIMENT No. 755 Care Of Aluminum Ware

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

APPARATUS: Old aluminum pan, vinegar and salt.

PROCEDURE: Pour some vinegar into the aluminum pan and heat gently. Note the corrosion which results. Place a little salt in the vinegar and note that it speeds up the corrosion.

278 FOODS AND HOUSEHOLD CHEMISTRY

EXPERIMENT No. 756 Testing Enamelware

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

APPARATUS: Black or red ink, enamel utensil.

PROCEDURE: Place a few drops of black or red ink on the outside of the enamelware to he tested. Allow the ink to dry and then wash it off with cold water. If no stains are left the enamelware is of good quality.

EXPERIMENT No. 757 The Reaction Of Zinc To Acids

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

APPARATUS: Zinc strip, vinegar, test tube, candle or alcohol lamp.

PROCEDURE: Place the zinc strip in a test tube half full of vinegar and heat carefully. Note the tendency of the zinc to dissolve.

SUMMARY: Soluble zinc compounds are quite poisonous and for this reason, kitchen utensils rarely, if ever, contain zinc.

EXPERIMENT No. 758 Effect Of Lye On Glass

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

APPARATUS: Lye, glass and stirring rod, teaspoon.

PROCEDURE: Place a spoonful of lye in a glass three quarters full of water and stir to dissolve. Set the glass aside for a few days. Pour off the liquid and note that the glass has been corroded.

EXPERIMENT No. 759 Test For Lead In Battery Term1nal Corrosion

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

APPARATUS: Battery terminal corrosion, sodium iodide solution and test tube.

PROCEDURE: Dissolve four measures of the corrosive material from a battery terminal in a test tube one quarter full of water. Add five drops of sodium iodide solution and shake thoroughly. Note that a yellow precipitate occurs. The yellow precipitate is lead iodide.

EXPERIMENT No. 760 Test For Copper In Terminal Corrosion

(CL-77)

APPARATUS: Battery terminal corrosion, sodium carbonate, nichrome wire, iron nail, ammonium hydroxide, candle or alcohol lamp.

PROCEDURE: Place three measures of the corrosive material in a test tube half full of water and shake to dissolve. Dissolve one measure of sodium carbonate in another test tube one quarter full of water and add a drop or two of the corrosion solution. Note whether a green precipitate appears. Dip the end of the nichrome wire into the corrosion and then insert it in the flame. Note whether the flame is green. Place an iron nail in the solution for a few minutes and then remove it from the solution. Note whether there is a thin copper coating on it.

LIONEL CHEM-LAB 279

Pour a few drops of ammonium hydroxide into the corrosion solution. Note that a deep blue color occurs denoting the presence of copper.

EXPERIMENT No. 761 Test For Sulfate In Terminal Corrosion

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

APPARATUS: Strontium chloride, battery terminal corrosion and two test tubes.

PROCEDURE: Dissolve three measures of the corrosive material in a test tube one half full of water. Place three measures of strontium chloride in another test tube one quarter full of water and shake to dissolve. Pour into this a little of the corrosion solution and note the white precipitate of strontium sulfate.

EXPERIMENT No. 762 Iron In Terminal Corrosion

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

APPARATUS: Battery terminal corrosion, sodium ferrocyanide, two test tubes.

PROCEDURE: Dissolve three measures of the corrosive material in a test tube one half full of water. Place two measures of sodium ferrocyanide in another test tube half full of water and shake to dissolve. Pour a few drops of the corrosion solution into this and note the color of the precipitate.

SUMMARY: Iron forms a blue precipitate with sodium ferrocyanide.

EXPERIMENT No. 763 Solubility Of Copper

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

APPARATUS: Copper strip, sodium bisulfate, household ammonia, alcohol lamp or candle, test tube.

PROCEDURE: Place three measures of sodium bisulfate in a test tube three quarters full of water and shake well. Add the copper strip and heat carefully. Note how the copper dissolves. Add a few drops of ammonia and note the blue color.

SUMMARY: Copper sulfate has been formed which turns deep blue when ammonia is added.

EXPERIMENT No. 764 Testing Laundry Blue For Ultramarine

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

APPARATUS: Laundry blue, sodium bisulfate, test tube.

PROCEDURE: Place one third measure of blue in a test tube one quarter full of water. Add three measures of sodium bisulfate and shake thoroughly. Note any change in color. Cautiously smell any odor liberated.

SUMMARY: If the odor is like that of rotten eggs, hydrogen sulfide is given off. If the blue is ultramarine the solution will turn colorless.

280 FOODS AND HOUSEHOLD CHEMISTRY

EXPERIMENT No. 765 Testing Laundry Blue For Prussian Blue

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

APPARATUS: Laundry blue, sodium carbonate, test tube, alcohol lamp or candle, test tube holder, measuring spoon.

PROCEDURE: Put one third measure of blue in a test tube one quarter full of water and shake well. Add two measures of sodium carbonate and heat gently. Note whether the color changes from blue to brown or dark red. If so, Prussian blue is present.

EXPERIMENT No. 766 Testing For Indigo In Laundry Blue

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

APPARATUS: Laundry blue, test tube, candle or alcohol lamp.

PROCEDURE: Place two measures of blue in a test tube and heat carefully. Note whether a purple vapor rises in the tube. Inhale cautiously to detect any odor. If indigo is present a purple gas and a strong odor will be produced.

EXPERIMENT No. 767 Removing Iodine Stains

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

APPARATUS: Sodium thiosulfate, iodine stained fabric, test tube.

PROCEDURE: Place two measures of sodium thiosulfate in a test tube half full of water and shake to dissolve. Rub this solution over the stain repeatedly. Note that the stain is removed from the fabric.

EXPERIMENT No. 768 Removing Coffee Stains

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

APPARATUS: Baking soda (store), stiff brush, alcohol lamp or candle.

PROCEDURE: Place a quarter teaspoonful of baking soda on each stain. Wet the brush and rub horizontally with the weave of the fabric. Rub until stains are removed.

EXPERIMENT No. 769 Removing Stains With Bleaching Powder

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

APPARATUS: Calcium hypochlorite, tartaric acid, sodium thiosulfate, ink-stained fabric and three test tubes.

PROCEDURE: Dissolve two measures of calcium hypochlorite in a test tube half full of water. Immerse the stained fabric in this solution for five minutes. Remove the fabric and place it in another test tube containing three measures of tartaric acid and three quarters of a test tube of water. Repeat the procedure to make certain that the stain is removed. Dissolve two measures of sodium thiosulfate in a third test tube one half full of water and dip the fabric into this for a few minutes. Remove the fabric from the test tube and rinse well with water.

LIONEL CHEM-LAB 281

EXPERIMENT No. 770 Removing Grease Stains With Corn Starch

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

APPARATUS: Corn starch, newspaper and brush.

PROCEDURE: Cover grease stain with corn starch and newspaper. Allow to stand for a while then remove paper and brush oif starch with a brush. Note that the stains have disappeared.

EXPERIMENT No. 771 Removing Grease Spots

(CL-66, CL-77)

APPARATUS: Calcium carbonate, electric iron, blotting paper, wad of cotton, carbon tetrachloride, grease spotted fabric.

PROCEDURE: Sprinkle some calcium carbonate over the spot on both sides of the cloth. Press this gently with a warm electric iron and note that the spot begins to disappear. Brush off the calcium carbonate. Rub the rest of the grease off with a wad of cotton saturated with carbon tetrachloride, being careful not to inhale any of the fumes.

SUMMARY: Carbon tetrachloride is a good solvent for grease.

EXPERIMENT No. 772 Testing Face Powder For Starch

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

APPARATUS: Face powder, ferric ammonium sulfate, sodium bisulfate, sodium iodide solution, alcohol lamp or candle and two test tubes.

PROCEDURE: Put two measures of face powder in a test tube half full of water and shake well. Heat to boiling point for a few minutes and set the tube aside to cool. Prepare some starch test solution as described in Experiment No. 688. Pour a few drops of this solution into the cooled face powder liquid and note whether a blue color sets in. If a blue color sets in, starch is present.

EXPERIMENT No. 773 How To Test Face Powder For Boric Acid

(CL-66, CL-77)

APPARATUS: Face powder, sodium bisulfate, alcohol, mortar and pestle and heating spoon.

PROCEDURE: Mix thoroughly in the mortar three measures of face powder and an equal amount of sodium bisulfate. Place this in the heating spoon and add a few drops of alcohol. Apply the flame directly to the contents and note whether a green flame results.

SUMMARY: Barium compounds cause a green flame reaction.

EXPERIMENT No. 774 How To Test To Depilatories For Sulfides

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

APPARATUS: Hair remover, sodium bisulfate, test tube, alcohol lamp or candle and sulfide test paper.

PROCEDURE: Mix in the test tube a small portion of the hair

282 FOODS AND HOUSEHOLD CHEMISTRY

remover, two measures of sodium bisulfate and a few drops of water. Insert in the tube a moistened piece of sulfide test paper and heat gently. Note whether a dark spot appears on the paper. Remove the tube from the flame occasionally and inhale cautiously. If you smell hydrogen sulfide gas, a sulfide is present.

EXPERIMENT No. 775 Preparing A Window Cleaner

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

APPARATUS: White soap shavings, glycerine, stirring rod, container and eye dropper.

PROCEDURE: Place five drops of glycerine in a container with twenty-five drops of soap shavings. Add a few drops of water until a smooth paste forms, then close the container. This material makes a good window cleaner.

EXPERIMENT No. 776 Testing For Acid Mouth

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

APPARATUS: Blue litmus paper.

PROCEDURE: Place a strip of blue litmus paper in your mouth for a few moments. Remove and note any color change. If the blue litmus paper turns red, your mouth is acid.

EXPERIMENT No. 777 A Soothing Burn Preparation

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

APPARATUS: Tannic acid, tumbler, cotton and stirring rod.

PROCEDURE: Put two measures of tannic acid in a tumbler. Add one test tube of water and stir to dissolve. Apply this solution to burns to relieve pain.

Go to Contents , Lionel Chem-lab Chapter 26 or Back to the Experiments Page