AN EXPERIMENT IN ALCHEMY:

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AN EXPERIMENT IN ALCHEMY: Powered By Docstoc
					Benard Trevisan:


He Looks for Gold

                         In a dark old lab sits, an alchemist (someone who tries to
                         make gold from other things), an old man in the act of
                         taking 2000 hen eggs in pots of boiling water. He takes the
                         shells off and puts them in a pile. He heats them over a
                         flame until            they turn white as snow. His partner
                         takes the whites from the yolks and places them in the
                         manure of white horses. He lets this sit for 8 long years.
                         They are trying to make gold.

                       The two men hoped to make the stone after years of
waiting. The time came to see. Failure! They were not able to turn anything into
gold—Least of all, horse ^%%$%^.

Benard Trevisan was born into an upper class family in 1406. Encouraged by his
parents, Benard began his dream to turn metals into gold. His family hoped to
make a lot of money. But as the years passed, Benard lost all of his money. His
family lost faith in Benard and felt sorry for him. They even thought he had turned
mad.

But Benard still had hope. The egg shell experiment did not work. But he had
other ideas. For ten more years, Benard tried over a thousand times, using flowers,
herbs, salts, animal fat, chemicals, and fur. Still failure! He would not give up.
He buried himself in a dungeon, where he set up his lab. Fifteen more years went
by.

By now, Benard had no money and his health was very poor. He moved his lab to
the Baltic Sea, where he started to use silver, acids, and fire. After years of
experiments, he had the same results. He felt tired and alone at the age of 62. He
went to his home to see his family, but they did not want to talk to him. Benard
decided to return to his lab. He wrote this right before he died in 1490:

“I did not think to die. Till I had finished what I had to do I thought to find the
secret”
   1.   In what year was Benard Trevisan born?_______________

   2. What did the two alchemists hope to make?________________

   3. Write down the step by step procedure the two alchemists used in their attempt to create
      gold in paragraph 1?




   4. Describe Benard Trevisan’s family support from the beginning of his quest to the end in
      his pursuit to make gold?




   5. Why do you think Benard’s health dramatically declined?



   6. Why did countries and empires invest so much into alchemists?




Essay Question:


        1.   In what ways did the pursuit to make gold advance the study of Chemistry?
AN EXPERIMENT IN ALCHEMY:
COPPER TO SILVER TO GOLD

INTRODUCTION

One of the goals of the ancient alchemists was to convert base metals into gold. Although this
goal was never attained by chemical methods, the alchemists were able to perform many color
changes to make metals resemble gold. The introduction of alchemy to the west came in the 8th
Century when the Arabs brought it to Spain. From here it quickly spread to the rest of Europe.

Pre Lab:

                                Coin #1                  Coin #2                   Coin #3

 Date of Penny

 Initial Mass

 Volume

 Density

1. Describe the penny in terms of physical properties.




2. What material is a penny made of?




3. Read over the Procedures on the next page. List any potential safety hazards.
Procedure:


1. In the hood, a sodium hydroxide and zinc solution have already been prepared. CAUTION:
DO NOT ALLOW THE SOLUTION TO ACTIVELY BOIL, HOT SODIUM
HYDROXIDE IS VERY CAUSTIC AND IT MAY SPATTER.




 2. Using the tongs, place two copper tokens into the hot solution and continue to heat gently.
Almost immediately, the copper tokens should begin to turn silvery white and small bubbles
of gas will fizz from the solution. Occasionally, using the tongs, rub the tokens into the zinc and
turn the tokens over. When the tokens have become completely silver, remove them from the
solution and immerse them in a beaker of distilled water. Wash the tokens well to remove any
sodium hydroxide and dry them.




3.Weigh the silver tokens and record the mass of each token on your data table.




4. Using the tongs, hold one of the silver tokens by the edges and heat it in the outer
cone of the Bunsen burner flame. Within a few seconds, the token will change color.
Heat it for three more seconds and then immediately quench it in a beaker of distilled
Water. The resulting gold token can be dried and polished with a towel.




5. Repeat this procedure with a second penny. Do not heat your third penny.




6. Weigh the gold tokens and record the mass of each token on your data table.
Data Table: Use the correct units!




                            Coin #1   Coin #2   Coin #3

Mass of clean dry silver
token


Mass of gold penny



Volume of gold penny




Density of gold penny




Change in mass of gold
penny (Initial-final)



Change in mass of silver
penny     (Initial-final)
Analysis Questions:


Name ________________________________________________________                  Course/Section ______________

Partner’s Name _______________________________________             Date ___________________




1. What happens to the copper tokens when they are placed in the sodium chloride/vinegar acid mixture?




2. Describe the changes that occur while heating the copper tokens in the sodium hydroxide-zinc mixture.




3. Is the silver colored coating on the copper token permanent? Does it rub off easily?




4. Is the gold colored coating on the copper token permanent? Does it rub off?




 5. Why is it necessary to quench the copper token in water after heating it to produce the color change?
(Note: You may want to try heating a token and allowing it to cool in the air.)
6. Compare the masses you measured, before and after the silver color change, for each of the tokens. How do the
masses compare?




7. The density of copper, zinc, silver, and gold are given in the table below. Based on this information, did you
really change the copper token into gold? Explain.

Metal Density in
g/mL
Copper 8.92
Zinc 7.14
Silver 10.5
Gold 19.3




8. One of the goals of the ancient alchemists was to turn metals into gold. How do you think they might have
reacted to this experiment? (Note: The ancient alchemists did not use balances to weigh things.)




9. When the penny turns a silver color, is this a physical or chemical change? Why?




10. When the penny forms a gold color, is this a physical or chemical change? Why?
11. What is the element that gives the penny its silver color?




12. What is an alloy?




13. What alloy did you make?

				
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