CHEMISTRY

2012-13Semester 2

2/14/13

• Entry Task

• Calculate the calories if 100 grams of water is heated 5 degrees Celsius.

• How many Calories is that?

2/19/13

• Entry Task

• Free Day!

2/20/13

• Entry Task

• How does a calorimeter work? Explain your answer in terms of calories, Calories, and temperature of the water before and after burning.

• Conduct our lab!! Everyone fill out the data sheet.

2/21/13

• Entry Task

• Identify and explain how and where thermal energy is being transferred in your calorimeter. Explain your answer in terms of convection, conduction, radiation, absorption, and reflection.

• http://science.yourdictionary.com

2/22/13

• Entry Task

• Say Something Nice• Please turn in your entry task papers!!

2/25/13

• Entry Task

• What is the boiling point of a substance? Use water as an example.

• Review and turn in thermodynamics lab. • Read pages 265-267. Answer questions 14-18

on page 267.

2/26/13

• Entry Task

• Look at the graphs on page 269. What happens to the temperature while ice is melting or water is boiling?

• Read pages 267 to 270. Answer questions 19-22 on page 270.

2/27/13

• Entry Task

• How do scientific ideas change over time? What influences the ideas?

Discuss Answers

• Scientists make predictions, conduct tests and share their results.

• Some of the predictions have evidence to be correct and others have evidence to be incorrect.

• Other scientists consider the results and conduct other tests and share those results.

• Over a long number of years, the knowledge grows and changes.

Take Notes!

• You will be making a timeline from the information in this movie.

• NOTES: – WHO - people, – WHAT - contributions to scientific ideas AND political

issues/ gender constraints of the era– WHERE - country where they conducted their work, – WHEN - YEAR(s) of effort– WHY – why was this discovery important?

2/28/13

• Entry Task

• What is a TIMELINE?

Discuss Answers

• A timeline is a graphic representation of the passage of time as a line. Either vertical like facebook or horizontal…

• EXAMPLE• http://1.bp.blogspot.com/-

zr2Mh-uoWfg/T6BQf69mDLI/AAAAAAAACmk/l_QQlVJ-sis/s1600/Timeline_Inventions.jpg

• Often, past on the left…current on the right. • Remember the spaces on the timeline should be even.

For example if you want to span 200 years over 10 inches, every inch would be 20 years.

3/1/13

• Entry Task

• Say Something Nice• Please turn in your entry task sheets!

3/4/13

• Entry Task

• List THREE interesting people and their discoveries from the movie last week.

Today’s Work

• Complete movie.• Discuss notes.• Set up timeline. • Complete your timeline with your partner.

– 1812 – Michael Faraday, electricity/magnetism, London, only gentleman are scientists– 1885 Einstein as a child– 1771 – Antoine Lavoisier, France, Conservation of Mass, French Revolution, he gets

guillotine—disliked tax collector– 1897 Einstein in high school, poor student, fascinated by light– 1846 – Faraday realizes electricity and magnetism are connected, invents electric

motor, names the “invisible light” electromagnetism– 1722- Emilie du Chatalay, France, before her time, translated Newton’s principia and

realized he had made an error, velocity should be squared, fell in love with poet Voltaire, died at 43

– 1905 – Einstein’s miracle year, Germany, 5 papers, including E=mc2 in 3 pages – 1919 – Fame finds Einstein and he divorces Mileva, marries cousin– 1907 – Berlin, Germany; Lisa Meitner becomes first professor (1912)of physics– 1920-30 “Golden Age of Nuclear Research”– 1930’s – Nazis drive out Jewish intellectuals; Einstein leaves in 1933; Meitner barely

escapes in 1938– 1938 – Sweden, Robert Frisch (nephew) and Meitner “split the atom” realizing that

lost mass is converted directly to energy during nuclear fission– 1942 Manhattan Project in US; bombs contain only a couple pounds of Uranium and

Plutonium

Gaps in your Notes

• http://www.pbs.org/wgbh/nova/physics/ancestors-einstein.html

• TIMELINE SCALE:• 1 inch = 20 years• ½ inch = 10 years• ¼ inch = 5 years• TIMESPAN: 1722-1942

3/5/13

• Entry Task

• Give a detailed example of how society influences science and technology and vice versa.

• Finish movie• Add detail and color to timelines

3/6/13

• Entry Task

• How did Einstein’s big ideas build on Faraday, Maxwell, Lavoisier and du Chatelier/Leibnitz?

• Also, where do you think physics and chemistry crossover?

3/7/13

• Entry Task

• Based on what you know of kinetic energy of molecules, will cold water or warm water have more dissolved oxygen?

Today’s Work

• We will test the dissolved oxygen content in tap water OR fishtank water (your choice!)

• Follow the instructions in the test kit. – Natosha – materials supervisor and reader of test

instructions– Krista – data recorder– Justin and Briana - technicians

• Put everything away for TOMORROW!

3/11/13

• Entry Task

• What does pH tell you about the fluid?• Find an answer in the textbook!

Today’s Work

• Complete a pH test. • Complete two more oxygen replicates• SET UP – 3 testing places at back tables for 7th

graders to do pH, nitrate and turbidity tests.• If time, complete a nitrate test and turbidity

test.

Answers

• pH stands strength of hydrogen. • Numbers closer to 14 mean more BASIC or

alkaline. • Numbers closer to 0 mean more ACIDIC. • Acid is between 0 and 6.9• Neutral 7• Basic is between 7.1 and 14.

3/12/13

• Entry Task

• What is happening when we add 8 drops of Manganous Sulfate Solution and 8 drops of Alkaline Potassium Iodide to the water sample?

• Read http://bit.ly/16ozZNS • Finish DO test. • Conduct turbidity, nitrate and pH tests.

3/13/13

• Entry Task

• What does the turbidity test tell you about our river water?

• Read and discuss packet on water quality parameters. • To Turn in: for each of the parameters (DO, BOD, pH,

turbidity and nitrates) discuss IN WRITING the apparent health of our river by comparing it to the optimal values given in the text.

• WATCH MOVIE!!

3/14/13• Entry Task• In the dissolved oxygen test, what chemistry is happening when

the solution turns from yellow to clear? • ANSWER: The thiosulfate molecule then reacts with any

I2 present.

• 2S2O32- + I2 = 2S4O 6

2- + 2 I-

• When the iodine (I2) molecules react, they break up into I- ions which are colorless.

• How does this help us know how many O2 molecules there are?• ANSWER: tells us that 4 molecules of the Sodium Thiosulfate

are required to change the color resulting from one molecule of O2 in the original water

Today’s Work

• One person – complete 3rd and 4th DO test• One person – complete BOD tests (3 trials)• One person – calculate averages and compile

the data onto the master sheet. • THIS DATA IS DUE TO THE Chehalis Basin

Education Consortium TODAY!!!

3/15/13

• Entry Task

• Say Something Nice• Please turn in your entry task sheets!

Today’s Work

• Find master data sheet on CBEC website• Transfer all data and averages to master sheet• Complete the essay:

ESSAY about our river data…

• For each of the parameters (DO, pH, turbidity and nitrates) discuss IN WRITING the apparent health of our river by comparing it to the optimal values given in the text.

• Explain how much higher or lower it is than optimal.

• Explain whether you think this is a good thing, bad thing, or just fine.

• Check with Ms. Maring when you think you’re done.

3/18/13

• Entry Task

• What do you know about balancing chemical equations?

• Is this equation balanced?• 2Na + H2O 2NaOH + H2

Today’s Work

• Read pages 207-210.• Answer #13 or 14 Questions on page 211. • Practice balancing equations at• http://education.jlab.org/elementbalancing/

3/19/13

• Entry Task

• Cl2 + NaBr Br2 + NaCl• Is this equation balanced? • If not, please balance it!!

3/20/13

• Entry Task

• Is this equation balanced?

• YES• Next time, I’ll count atoms before I start balancing!!

• If not, please balance it.

CH5N  +  11O2  → CO  +  10H2

O +  NO2

111

Today’s Work

• Complete balancing chem equations assignment.

• Work on any missing work. • Start studying for quiz: – Thermodynamics/Calorimeter– History of e=mc2– Water Quality Testing– Balancing Equations

3/21/13

• Entry Task

• Write your first Jeopardy Q and A for the upcoming quiz.

• TOPICS– Thermodynamics/Calorimeter– History of e=mc2– Water Quality Testing– Balancing Equations

• Today’s Work – complete 15 Jeopardy Q and A.

3/25/13

• Entry Task

• Give one…what do you know about:– Thermodynamics/Calorimeter– History of e=mc2– Water Quality Testing– Balancing Equations

• Call things out…write them down.

3/26/13

• Entry Task

• For which portion of the test categories do you feel least prepared? – Thermodynamics/Calorimeter– History of e=mc2– Water Quality Testing– Balancing Equations

•

History of E=mc2• How did Einstein’s big ideas build on Faraday, Maxwell, Lavoisier and du

Chatelier/Leibnitz?• Faraday discovered the interaction of electricity and

magnetism and made an electric motor. • Maxwell figured out speed of light• Lavoisier figured out conservation of mass. • Einstein used the above 3 discoveries so that ENERGY

becomes MASS at the speed of light squared. • Du Chatelier figured out that speed had to be

squared.

Water Quality

• What does the turbidity test tell you about our river water?

• ANSWER: It tells us how much suspended (floating) solid material is in the water. Low turbidity is good because less dirt for gills and more light for plants.

• What does the dissolved oxygen test tell us about our river water?

• ANSWER: How much oxygen is dissolved in the water. If the water is warmer, there will be less oxygen because the kinetic energy of the molecules is increased and the oxygen will bounce out!

Balancing Equations

• How would you know when an equation is balanced? USE words REACTANTS and PRODUCTS in your answer.

• When there is the same NUMBER OF REACTANT ATOMS as there are NUMBER OF PRODUCT ATOMS

• Is this equation balanced? NO, not enough H’s • 2Na + H2O 2NaOH + H2

• BALANCED: 2Na + 2H2O 2NaOH + H2

Calorimetry

• QUESTION:How does a calorimeter work? Explain your answer in terms of calories, Calories, and temperature of the water before and after burning.

• ANSWERS:• A calorimeter measure how many calories are in food. • We measured the mass burned and measured change in

temperature of the water. The heat of burning transferred to the water and thus we can calculate calories of the burned food.

• 1000 calories = 1 Calorie (Kcal or kilocalorie)• 1 calorie is the amount of energy needed to heat 1 gram of

water 1 degree celsius.

3/27/13

• Entry Task

• Can you recall the 2 laws of Thermodynamics we’ve studied??

Which leads us to two important LAWS:

• The First law of thermodynamics.– It states that energy cannot be created or destroyed – it can

only change forms.– Also called “Law of Conservation of Energy.”– First proposed by a German medical doctor, Julius Robert

von Mayer in 1842. He did not get much credit for his idea.– In 1844, James Joule comes to same conclusion and he gets

credit because he is established in the scientific community. (Unit of energy named a Joule)

The 2ND law of thermodynamics.

• It states that energy in a system spreads out if it can. It moves from hot to cold.

• Heat never flows from cold to hot.• Also called “Law of Entropy”. Entropy can

loosely be called the disorder of energy in a system. (Energy that is NOT available for useful work.)

• AKA: Everything gets cold and falls apart

4/8/13

• Entry Task

• Does anyone know what a MOLE is? In Chemistry!?

ANSWERS

• 6.02 x 1023

• Avogadro’s Number• ANALOGY: a dozen. How many eggs in a

dozen? How many chickens is a dozen chickens? Houses? People?

• A mole is 6.02 x 1023 atoms or molecules of any substance.

Today’s Work

• Watch 2 videos and take notes: http://www.kentchemistry.com/moviesfiles/chemguy/advanced/ChemguyMole.htm

• Read about it and do some practice problems:• “The Mole” on pages 179-184. Answer

questions 16, 17 and 18.

4/9/13

• Entry Task

• What is the mass in grams of 2 moles of H atoms? Show your work!

• “The Mole” on pages 179-184. Answer questions 16, 17 and 18.

• “Moles and Formula Units on pages 184-186. Answer questions 22-27 on page 186.

• “the Mathematics of Chemical Equations” on pages 239-243…Answer review questions 6-11 on page 243.

4/10/13

• Entry Task

• What is the mass of 1 mole of H2O? Show your work!

4/11/13

• Entry Task

• For the following equation:• 6CO2+6H2O —> C6H12O6+6O2• If it starts with 12 moles of CO2, how many moles of C6H12O6

will be produced?

4/12/13

• Entry Task

• Say Something Nice• Please turn in your entry task sheets!!

• Turn in all homework!!

4/15/13

• Entry Task

• What does STOICHIOMETRY mean? The ratios in a balanced chemical equation and everything you can mathematically calculate from that.

• #10 from practice problems…

• Conduct Lab – goggles and aprons

4/16/13

• Entry Task

• From the lab sheet, what is the mole ratio of iron to copper?

• Will the gram masses be in the same ratio? Why or why not?

• Answer analysis and questions – turn in lab

More Mole Practice…

• A little more practice today and tomorrow for quiz on Thursday!

4/17/13

• Entry Task

• How many grams per mole of CH4 ?

• How many moles in 21.6 grams of CH4?

• How many molecules are there in 21.6 grams of CH4?

• Finish lab questions• More mole math practice worksheets

4/18/13

• Entry Task

• Freebie! • What else can we do without Justin here?

4/19/13

• Entry Task

• NONE!• Please turn in your entry task sheet.

• QUIZ – TO GET ALL POINTS,• SHOW YOUR WORK