CHEMISTRY CHEMISTRY 8-24-07 Friday (p.1)8-24-07 Friday (p.1)WARM-UP:WARM-UP: How do you exit from this How do you exit from this room in case of fire? Tornado? room in case of fire? Tornado?

TODAY’S GOALS:TODAY’S GOALS:1) Finish notes for Crazy Rocket.1) Finish notes for Crazy Rocket.2) “What chemical is it?”Activity 2) “What chemical is it?”Activity (prizes!!)(prizes!!)3) Lab Safety Rules--Explain & sign.3) Lab Safety Rules--Explain & sign.HW: HW: Sec. 8.2—Read & take notes.Sec. 8.2—Read & take notes.

1. How do you exit from this room in case of fire?

2. How do you exit from this room in case of Tornado?

Out room to left, down stairs, outside to DF lot space #25

Out room to left, down stairs, line up against hall; sit or kneel & cover face

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Equation for the reaction:Equation for the reaction:

(C(C66HH1010OO55))nn(s) + O(s) + O22(g) (g)

CO CO22(g) + H(g) + H22O(g)O(g)

cellulose + oxygen produces

carbon dioxide + water

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Reaction TypeReaction Type

CombustionCombustion::

Any reaction where a substance Any reaction where a substance (usually a (usually a hydrocarbonhydrocarbon) is ) is combined with combined with oxygenoxygen to to produce produce carbon dioxide carbon dioxide and and waterwater

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Energy changesEnergy changes

Because Because heat is released heat is released in this in this reaction it is called an reaction it is called an ““exothermicexothermic” reaction.” reaction.

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Why does the “rocket” lift off?Why does the “rocket” lift off?

The heat produced heats the air The heat produced heats the air “inside” the rocket; “inside” the rocket; hot air is hot air is less dense than cooler airless dense than cooler air, so the , so the rocket “lifts” off.rocket “lifts” off.

CHEMISTRY CHEMISTRY 8-24-07 Fri (per 3,6,7)8-24-07 Fri (per 3,6,7)WARM-UP:WARM-UP: What is produced in a What is produced in a combustion reaction? combustion reaction?

TODAY’S GOALS:TODAY’S GOALS:1) Turn in essay & signed contracts.1) Turn in essay & signed contracts.2) “What chemical is it?”Activity Notes 2) “What chemical is it?”Activity Notes & prizes. & prizes. 3) Take Sec. 8.2 quiz & safety quiz. 3) Take Sec. 8.2 quiz & safety quiz. 4) Ira Remsen Demonstration.4) Ira Remsen Demonstration.5) Lab Safety Rules—more??!!5) Lab Safety Rules—more??!!HW: HW: Sec. 1.1-1.2—Read & take notes.Sec. 1.1-1.2—Read & take notes.

Carbon dioxide (CO2) & water (H2O)

What is produced in a What is produced in a combustion reaction?combustion reaction?

CC66HH1212OO6 6 (s)(s)

formulachemical symbol

(the letter)

subscript(the number)

state symbol

ring standround bottom flask

iron ringpre-1982 penny

clamprubber stopper

tubinggraduated cylinder

To be read during the reaction: While reading a textbook of chemistry I came upon the

statement, "nitric acid acts upon copper." I was getting tired of reading such absurd stuff and I was determined to see what this meant. Copper was more or less familiar to me, for copper cents were then in use. I had seen a bottle marked nitric acid on a table in the doctor's office where I was then "doing time." I did not know its pecularities, but the spirit of adventure was upon me. Having nitric acid and copper, I had only to learn what the words "act upon" meant. The statement "nitric acid acts upon copper" would be more than mere words.

To be read during the reaction: All was still. In the interest of knowledge I was even

willing to sacrifice one of the few copper cents then in my possission. I put one of them on the table, opened the bottle marked nitric acid, poured some of the liquid on the copper and prepared to make an observation. But what was this wonderful thing which I beheld? The cent was already changed and it was no small change either. A green-blue liquid foamed and fumed over the cent and over the table. The air in the neighborhood of the performance became colored dark red. A great colored cloud arose. This was disagreeable and suffocating. How should I stop this?

To be read during the reaction: I tried to get rid of the objectionable mess by picking it

up and throwing it out of the window. I learned another fact. Nitric acid not only acts upon copper, but it acts upon fingers. The pain led to another unpremeditated experiment. I drew my fingers across my trousers and another fact was discovered. Nitric acid acts upon trousers. Taking everything into consideration, that was the most impressive experiment and relatively probably the most costly experiment I have ever performed... It was a revelation to me. It resulted in a desire on my part to learn more about that remarkable kind of action. Plainly, the only way to learn about it was to see its results, to experiment, to work in a laboratory.[3]

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Equation for the reaction:Equation for the reaction:

Cu(s) + HNOCu(s) + HNO33(aq) (aq)

NONO22(g) + H(g) + H22O(l) + Cu(NOO(l) + Cu(NO33))22(aq)(aq)

reactants reactants products products

Copper + nitric acid produces

nitrogen + water + copper(II)nitrate dioxide

things on the left things on the right

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State symbolsState symbols

““s” = solids” = solid““l” = liquidl” = liquid““g” = gasg” = gas““aq” = aqueous (dissolved in aq” = aqueous (dissolved in

water)water)

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Energy changesEnergy changes

Because heat is released in this Because heat is released in this reaction it is called an reaction it is called an “exothermic” reaction.“exothermic” reaction.

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Why does the penny have to be “old”?Why does the penny have to be “old”?

Pre-1982 pennies are mostly Pre-1982 pennies are mostly copper.copper.

Post-1982 pennies are made up Post-1982 pennies are made up of a zinc core surrounded by a of a zinc core surrounded by a thin layer of copper.thin layer of copper.

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Chemistry of ColorChemistry of Color

The NOThe NO22 gas produced is brown gas produced is brown

—ALL COLORED GASES —ALL COLORED GASES ARE POISONOUS.ARE POISONOUS.

Copper ions tend to produce Copper ions tend to produce blue solutions.blue solutions.