Nitric Acid Acts Upon Copper

While reading a textbook of chemistry I While reading a textbook of chemistry I came upon the statement, "nitric acid acts came upon the statement, "nitric acid acts upon copper." I was getting tired of upon copper." I was getting tired of reading such absurd stuff and I was reading such absurd stuff and I was determined to see what this meant. determined to see what this meant. Copper was more or less familiar to me, Copper was more or less familiar to me, for copper cents were then in use. I had for copper cents were then in use. I had seen a bottle marked nitric acid on a table seen a bottle marked nitric acid on a table in the doctor's office where I was then in the doctor's office where I was then "doing time.""doing time."

I did not know its peculiarities, but the I did not know its peculiarities, but the spirit of adventure was upon me. Having spirit of adventure was upon me. Having nitric acid and copper, I had only to learn nitric acid and copper, I had only to learn what the words "act upon" meant. The what the words "act upon" meant. The statement "nitric acid acts upon copper" statement "nitric acid acts upon copper" would be more than mere words.would be more than mere words.

All was still. In the interest of knowledge All was still. In the interest of knowledge I was even willing to sacrifice one of the I was even willing to sacrifice one of the few copper cents then in my possession. I few copper cents then in my possession. I put one of them on the table, opened the put one of them on the table, opened the bottle marked nitric acid, poured some of bottle marked nitric acid, poured some of the liquid on the copper and prepared to the liquid on the copper and prepared to make an observation. But what was this make an observation. But what was this wonderful thing which I beheld?wonderful thing which I beheld?

The cent was already changed and it was The cent was already changed and it was no small change either. A green-blue no small change either. A green-blue liquid foamed and fumed over the cent liquid foamed and fumed over the cent and over the table. The air in the and over the table. The air in the neighborhood of the performance became neighborhood of the performance became colored dark red. A great colored cloud colored dark red. A great colored cloud arose. This was disagreeable and arose. This was disagreeable and suffocating. How should I stop this?suffocating. How should I stop this?

I tried to get rid of the objectionable mess I tried to get rid of the objectionable mess by picking it up and throwing it out of the by picking it up and throwing it out of the window. I learned another fact. Nitric window. I learned another fact. Nitric acid not only acts upon copper, but it acts acid not only acts upon copper, but it acts upon fingers. The pain led to another upon fingers. The pain led to another unpremeditated experiment. I drew my unpremeditated experiment. I drew my fingers across my trousers and another fingers across my trousers and another fact was discovered. Nitric acid acts upon fact was discovered. Nitric acid acts upon trousers. trousers.

Taking everything into consideration, Taking everything into consideration, that was the most impressive experiment that was the most impressive experiment and relatively probably the most costly and relatively probably the most costly experiment I have ever performed... It experiment I have ever performed... It was a revelation to me. It resulted in a was a revelation to me. It resulted in a desire on my part to learn more about desire on my part to learn more about that remarkable kind of action. Plainly, that remarkable kind of action. Plainly, the only way to learn about it was to see the only way to learn about it was to see its results, to experiment, to work in a its results, to experiment, to work in a laboratory.laboratory. Ira RemsenIra Remsen

Ira Remsen, born in New York City in Ira Remsen, born in New York City in 1846, was originally trained as a 1846, was originally trained as a medical doctor but left that field to study medical doctor but left that field to study chemistry and went on to become a chemistry and went on to become a leader in chemical education and leader in chemical education and research and to become the president of research and to become the president of Johns Hopkins University. He was the Johns Hopkins University. He was the accidental discoverer of saccharin, an accidental discoverer of saccharin, an artificial sweetener.artificial sweetener.

““Plainly, the only way to learn about it Plainly, the only way to learn about it was to see its results, to experiment, to was to see its results, to experiment, to work in a laboratory.”work in a laboratory.”

We learn chemistry We learn chemistry by doing chemistry.by doing chemistry.

In this lab you will be following In this lab you will be following copper through a series of steps copper through a series of steps called the …called the …

The The Copper Copper CycleCycle

The The Copper Copper CycleCycle

A series of reactions A series of reactions involving copper involving copper

where the reactants in where the reactants in one step are the one step are the

products from the products from the previous step.previous step.

The major drawback to The major drawback to this experiment is the first this experiment is the first step.step. The reaction that The reaction that

Ira Remsen described.Ira Remsen described.

The reaction where nitric The reaction where nitric acid acts upon copper.acid acts upon copper.

The nitric The nitric acid itself acid itself

is dangerous.is dangerous.

The brown gas is toxic.

Use a fume hood!

The brown gas is toxic.

This reaction This reaction mustmust be be done in a hood!done in a hood!

If you don’t have a If you don’t have a hood, don’t do the hood, don’t do the

reaction!reaction!

Why are you Why are you notnot doing this reaction? doing this reaction?

Consider the MSDS – the material Consider the MSDS – the material safety data sheet. It tells all about safety data sheet. It tells all about

the hazards of working with a the hazards of working with a particular substance.particular substance.

Check out the one for NOCheck out the one for NO22, ,

nitrogen dioxide.nitrogen dioxide.

Why are you not doing this reaction?Why are you not doing this reaction?

What are the hazards of What are the hazards of working with NOworking with NO22??

Check out the one for NOCheck out the one for NO22, ,

nitrogen dioxide.nitrogen dioxide.

SKIN CONTACT:SKIN CONTACT: Contact with liquid causes a severe Contact with liquid causes a severe corrosive action on the skin or eyes.corrosive action on the skin or eyes.

SKIN ABSORPTION:SKIN ABSORPTION: Unknown Unknown

EYE:EYE: See Skin Contact, above See Skin Contact, above

INHALATION:INHALATION: Vapors are a strong irritant to the Vapors are a strong irritant to the pulmonary tract. Initial symptoms of inhalation may be pulmonary tract. Initial symptoms of inhalation may be moderate and include irritation of the eyes and throat, moderate and include irritation of the eyes and throat, tightness of the chest, headache, nausea and gradual loss of tightness of the chest, headache, nausea and gradual loss of strength. Severe symptoms may be delayed (possibly for 5 strength. Severe symptoms may be delayed (possibly for 5 to 7 hours) and include cyanosis, increased difficulty in to 7 hours) and include cyanosis, increased difficulty in breathing, irregular respiration, lassitude and possible breathing, irregular respiration, lassitude and possible eventual death due to pulmonary edema in untreated cases.eventual death due to pulmonary edema in untreated cases.

INGESTION:INGESTION: None None

ACUTE OVER EXPOSURE EFFECTS:ACUTE OVER EXPOSURE EFFECTS: The vapor is The vapor is highly toxic and hazardous because of its ability to cause highly toxic and hazardous because of its ability to cause delayed chemical pneumonitis and pulmonary edema. The delayed chemical pneumonitis and pulmonary edema. The absence of market acute irritation of nitrogen dioxide limits absence of market acute irritation of nitrogen dioxide limits its warming properties. Contact with the liquid cause a its warming properties. Contact with the liquid cause a corrosive or chemical etching action on the skin or eyes. corrosive or chemical etching action on the skin or eyes.

CHRONIC OVER EXPOSURE EFFECTS:CHRONIC OVER EXPOSURE EFFECTS: Chronic or Chronic or repeated exposure may cause a permanent decrease in repeated exposure may cause a permanent decrease in pulmonary function (silo filler's disease).pulmonary function (silo filler's disease).

EXPOSURE LIMITS:EXPOSURE LIMITS: TWA = 3 molar ppm; STEL = 5 TWA = 3 molar ppm; STEL = 5 molar ppm (ACGIH 1995-1996)molar ppm (ACGIH 1995-1996)

IRRITANCY OF PRODUCT:IRRITANCY OF PRODUCT: See above See above

SENSITIZATION TO MATERIAL:SENSITIZATION TO MATERIAL: None known None known

CARCINOGENICITY, REPRODUCTIVE EFFECTS:CARCINOGENICITY, REPRODUCTIVE EFFECTS: None knownNone known

TERATOGENICITY, MUTAGENICITY:TERATOGENICITY, MUTAGENICITY: Mus-rat-ihl - 15 ppm/3 h continuousMus-rat-ihl - 15 ppm/3 h continuous

TOXICOLOGICALLY SYNERGISTIC PRODUCTS:TOXICOLOGICALLY SYNERGISTIC PRODUCTS: None knownNone known

Now you are going to see how Now you are going to see how nitric acid acts upon copper.nitric acid acts upon copper.

Several copper pennies will be Several copper pennies will be placed into a solution of placed into a solution of concentrated nitric acid.concentrated nitric acid.

What is the formula for nitric acid?What is the formula for nitric acid?

HNOHNO33

The 18M stock The 18M stock solution of solution of nitric acid.nitric acid.

A 4M solution of A 4M solution of nitric acid.nitric acid.

Copper pennies.Copper pennies.

The pennies are The pennies are placed into a placed into a beaker of nitric beaker of nitric acid, HNOacid, HNO33, in a , in a

fume hood.fume hood.

A watch glass A watch glass makes the gas makes the gas more visible.more visible.

Check out the Check out the temperature temperature change.change.

What changes What changes do you observe do you observe in the liquid?in the liquid?

This sample This sample went from went from

22C to 38C.22C to 38C.

The reaction is The reaction is stopped by stopped by removing the removing the pennies..pennies..

What changes What changes do you observe do you observe in the pennies?in the pennies?

How has the How has the liquid phase liquid phase changed?changed?

With what With what acids will acids will copper react?copper react?

What accounts What accounts for the color?for the color?

The pennies The pennies used must used must have been have been minted before minted before 1982.1982.

Why?Why?

2. Indicators of chemical reaction?2. Indicators of chemical reaction?3. Exothermic or endothermic?3. Exothermic or endothermic?4. Energy vs reaction pathway4. Energy vs reaction pathway5. Why concentrated HNO5. Why concentrated HNO33??

6. Factors affecting reaction rates?6. Factors affecting reaction rates?7. Predicting products from properties7. Predicting products from properties8. What are the types of reactions? 8. What are the types of reactions? 9. What type of reaction is it?9. What type of reaction is it?

1. How do we know a reaction occurs?1. How do we know a reaction occurs?

11. Redox11. Redox12. Oxidation number changes12. Oxidation number changes13. Balanced chemical equation13. Balanced chemical equation14. Net ionic equation14. Net ionic equation15. Nomenclature.15. Nomenclature.

And that is just for the reaction in And that is just for the reaction in step one …step one … as nitric acid is acting as nitric acid is acting

upon copper.upon copper.

10. Single replacement? 10. Single replacement?

Step 2 Step 2 Add about 20 drops of the Add about 20 drops of the solution from Step 1 to a solution from Step 1 to a test tube.test tube.

Add enough drops of sodium hydroxide, Add enough drops of sodium hydroxide, NaOH, until the no additional change NaOH, until the no additional change occurs.occurs.

Of what precautions should you be aware?Of what precautions should you be aware?

What is litmus paper used for?

Step 3 Step 3 Place the test tube in a Place the test tube in a beaker of boiling water beaker of boiling water until the change is until the change is complete.complete.

What are some What are some potential hazards in potential hazards in this step?this step?

Step 3 Step 3 When the reaction is When the reaction is complete, it is necessary to complete, it is necessary to wash the product.wash the product.

Add enough water to Add enough water to make the test tube half make the test tube half filled. Stir and allow the filled. Stir and allow the product to settle and pour product to settle and pour off (decant) the water.off (decant) the water.

What is What is being being removed by removed by the washing the washing process?process?

Step 4 Step 4 Add enough sulfuric acid, Add enough sulfuric acid, HH22SOSO44, to the test tube so , to the test tube so

that a complete change that a complete change occurs.occurs.

Are there any hazards in this step?Are there any hazards in this step?

It may help to use your stirring rod.It may help to use your stirring rod.

Step 5 Step 5 Add several small pieces Add several small pieces of zinc metal (Zn) to the of zinc metal (Zn) to the test tube.test tube.

Are there any hazards in this step?Are there any hazards in this step?

Do NOT stir, it’s Do NOT stir, it’s more interesting if more interesting if you don’t.you don’t.

Use a magnifying Use a magnifying glass to observe glass to observe the reaction as it the reaction as it takes place.takes place.

What evidence do you have?What evidence do you have?What kind of reaction?What kind of reaction?What are the products?What are the products?Write a balanced chemical equation.Write a balanced chemical equation.Write a balanced net ionic equation.Write a balanced net ionic equation.Why are the two equations different?Why are the two equations different?What other reaction occurred?What other reaction occurred?Is there evidence for it?Is there evidence for it?What other tests could you perform?What other tests could you perform?

Step 2 - Did a reaction occur? Step 2 - Did a reaction occur?

The following slides are used The following slides are used in reviewing the reactions after in reviewing the reactions after the lab is complete.the lab is complete.

What kind of reaction?What kind of reaction?What are the products?What are the products?Write a balanced chemical equation.Write a balanced chemical equation.Write a balanced net ionic equation.Write a balanced net ionic equation.Why are the two equations the same?Why are the two equations the same?Did any other reaction occur?Did any other reaction occur?Upon what did you make that Upon what did you make that prediction?prediction?

Step 3 - How do you know a reaction Step 3 - How do you know a reaction occurred? occurred?

What kind of reaction?What kind of reaction?What are the products?What are the products?Write a balanced chemical equation.Write a balanced chemical equation.Write a balanced net ionic equation.Write a balanced net ionic equation.Why are they not the same?Why are they not the same?What similarity can you see between What similarity can you see between the products of Step 1 and this step?the products of Step 1 and this step?

What would account for this?What would account for this?

Step 4 - How do you know a reaction Step 4 - How do you know a reaction occurred? occurred?

What kinds of reactions are they?What kinds of reactions are they?What are the products of each?What are the products of each?Write balanced chemical equations.Write balanced chemical equations.Write balanced net ionic equations.Write balanced net ionic equations.What evidence do you have that the What evidence do you have that the reactions you predict are occurring?reactions you predict are occurring?

Why was it necessary to wash the Why was it necessary to wash the solid (precipitate) in Step 3?solid (precipitate) in Step 3?

Step 5 - Two reactions are occurring. Step 5 - Two reactions are occurring.

Copper Lab

Balancing EquationsEvidence of

reaction

Types of reactions

Predicting products

Acid/base neutralization

Net ionic equations

REDOX

Reaction rate factors

pH and [H+]

Stoichiometry

Activity series

Solubility rules

Acids

Stock system

Nomenclature

1. Precipitate2. Gas given off3. Temperature change4. Color change

1. Synthesis2. Decomposition3. Single replacement4. Double replacement5. Combustion of a hydrocarbon

1. Concentration2. Temperature3. Surface area4. Catalyst

Thermodynamics Endothermic & exothermic

Reaction pathway diagramsActivation energy

Oxidizing and reducing agents

Strong & weak

The Copper Cycle LabThe Copper Cycle Lab

Comments or questions may be directed to

Mike JonesPisgah High School

Canton NC

mjones@haywood.k12.nc.us

07/13/0506/02/10