Penny For your Thoughts

Unit 1 • Investigation I

ChemCatalyst

• Long ago, people tried to turn ordinary things into gold. This pursuit was called alchemy and the people who engaged in alchemy were called alchemists. –Do you think the alchemists were successful

in turning things to gold? Explain your thinking.

ChemCatalyst

• Long ago, people tried to turn ordinary things into gold. This pursuit was called alchemy and the people who engaged in alchemy were called alchemists.

• Do you think with all the advances in technology that we can find a cheap method to turn things into gold?

Unit 1 • Investigation I

Activity• Purpose: In this activity you will be

transforming a copper penny and discussing what happens.

• Safety Note: You must weat safety goggles at all times. DANGER! Sodium hydroxide will burn skin, eyes, and clothing.

(cont.)

Unit 1 • Investigation I

The Big Question

–Can we turn a penny into gold?

Unit 1 • Investigation I

You will be able to:

– Follow a procedure using lab equipment and describe your observations.

Materials• Penny• 2 tongs• Hot plate• Bunsen burner• Striker• Goggles• Paper towels• 2 100 ml –beaker• 1 250 ml beaker half filled

with water• Lab gloves

• Chemicals:– Zinc filings (just enough to

cover the bottom of the 100 ml beaker (10 g)

– 25 ml of 3M sodium Hydroxide

– Cold tap water

Steps to make the NAOH solution

• Must be 3 M

• For 1 M you would use 40 g of NaOH to make a 1L solution

• Put 40 g in about .8 liters, dissolve, then fill to 1 liter mark

• Triple amount of NaOH to get 3 M

• Since we need only about 0.5 L, cut total in ½

• Thus mix 60 g of NaOH into 400 ml of water then fill to 500 ml level

Lab Jobs to be divided up• Safety Czar:

– Make sure everybody is wearing goggles– Gloves are being used where appropriate– Hair and sleeves have been addressed by all– Team members are keeping safe distance– In charge of Group’s actions

• Penny Mover– Uses tongs to place penny into Sodium hydroxide solution and takes penny out when finished– Places penny into water

• Hot Plate specialist– Turns on and monitors Solution on Hotplate, makes sure beaker is in middle– Records the initial and final amounts of solution in beaker– Turns off hot plate when section is done

• Sodium Hydroxide Holder– Uses tongs to hold Sodium Solution Beaker as Penny Mover does his tasks– In charge of getting a beaker of sodium hydroxide solution from fume hood at start of class and returning

cool beaker at end of period

• Blocker/Flame Keeper/Spill Patrol– Makes sure that no one bumps Sodium Hydroxide holder as they walk with solution beaker – Lights and monitors Bunsen Burner– Turns off Gas at end of lab

All students will heat their own penny

PROCEDURE

For silvering the penny1. Place zinc filling in beaker,

covering bottom2. Carefully add 20 ml of NAOH

solution to beaker3. Place on hot plate and set to

4, if liquid boils, turn down 4. Use tongs to place penny in

beaker, with help5. Once it turns completely

silver remove with help6. Place penny in 250ml beaker

to cool and rinse

For turning penny into gold• Set up Bunsen burner• Light burner with

striker/match• Adjust flame using metal collar

(blue is hottest)• Use tongs to place silver penny

into flame• Hold penny in flame only until

it changes color, no longer• Place in 250ml beaker to cool

down

Safety check

• Shoes• Hair• Clothing• Goggles

The running of the Penny lab

• This lab will be done under the direct supervision of the teacher, because of the dangers involved

• Any action taken by a student that I deem detrimental to the class will be dealt with swiftly and harshly!

Steps to the lab

• Step 1 is prep and safety (goggles!, review safety tips)

• Step 2: Turn the penny silver by placing it into a heated solution that contains Sodium Hydroxide and Zinc

• Step 3: Turn Penny into gold by putting it into the flame of a Bunsen burner

• When you are not active in the lab, you should be observing others and answering questions

Clean up

• Any spills of Sodium Hydroxide must be immediately addressed

• Use paper towels to stop flow (make sure you are wearing goggles and gloves)

• Turn off hot plates once you are done with them, BEFORE you go on to Bunsen Burners

• Turn off gas to burners after you are completed with section

Response to questions

• Get out the composition book

• Add any other observations from the class to your own if you believe they improve what you have written. Note who said what

Questions to be answered in lab

In comp book

Question 1

Describe what you observed during the experiment.

a. Label and describe the materials/devices used, how they were set up for use, and what actions occurred.

b.After the step took place, indicate the general results with as much detail as possible

Question 2

• What do you think happened to turn the penny silver?

Question 3

• What do you think happened to turn the penny gold?

Question 3Making Sense

• Do you think you made real gold? Explain your response.

Question 4Making sense

• How could you find out if you did make real gold?

At the end of class

• Picture

• If you do not want your penny, I will keep it

Discussion of mass and volume requires one to understand what matter is

Which is the main focus of our next section