Archive – week 6 – 19-20
Week of 10/7 – 10/11
10/7 – Monday – period 2
1. Test questions/ quick review
2. Mole concept – complete – review of filling boxes of volumes from Gay-Lussacs
– STM review/ piezo electric crystal / quartz watch
period 3/4
1. Test questions/ quick review
2. Mole concept – complete – review of filling boxes of volumes from Gay-Lussacs
– STM review/ piezo electric crystal / quartz watch
3. Lecture zero start in class – Determining chemical formulas!
a) Empirical vs. Molecular And ionic vs molecular
b) How many moles of parts to the whole.
4. Lab 5 – Lab 5 – Determination of Empirical formula of a Hydrate –
Mole THeory Presentation:
10/7 – Monday – Homework:
1. Please complete another submission of the weekends homework form.
2. Watch lecture 0 below.
3. Please answer question 2 on the first side of the worksheet and review with key that is posted below.
Lecture 0 : Determining Chemical Formulas from empirical data (Mole concept)
4: Please watch lecture 0a ( I model question 3) and complete question 4 on
Analytical Chemistry I – determining chemical formulas.pdf worksheet
End Monday!..
10/8 – Tuesday – period 2/3
Why we need a mole notes: H + Cl –> HCl
We can use a scale to count!
1. Homework Lecture 0 review – combustion analysis, percent by mass tie into today’s Lab
Form second responses
2. Mole ratios! Classwork! Exciting times we can now see atoms without looking at them!!!
a) Empirical vs. Molecular And ionic vs molecular
b) How many moles of parts to the whole.
3. Lab 5 – Lab 5 – Determination of Empirical formula of a Hydrate –
4. Conservation of Mass Presentation during heatings –
Flaming Flask Demo –
Cyclohexane combusts more completely when poured out because the ratio of
cyclohexane to oxygen is 1 : 9. We get those ratios when we balance.
That means 9 O2 molecules per 1 C6H12 is needed to maximize the reaction. The cyclohexane was not getting the right ratio in the flask but achieved the right ratio when it was poured out.
1 C6H12 (l) + 9 O2 (g) —–> 6 CO2 (g) + 6 H2O (g)
–period 4
Why we need a mole notes: H + Cl –> HCl
We can use a scale to count!
1. Complete the piezo electric discussion – quartz watch
2. Homework Lecture 0 review – combustion analysis, percent by mass tie into today’s Lab
3. Lab 5 – Lab 5 – Determination of Empirical formula of a Hydrate –
Flaming Flask Demo – description above
NOTES*Lesson for Lab 5 –
*Determine the chemical formula of a hydrate:
Because of the conservation of mass by Antoine Levassuer, the mass of water that is released from the crystal (hydrate) is the same mass that was is in the crystal. THus the moles of water lost is the water that are in the crystal (in the formula ) .
Formulas of compounds are fixed! (THanks Joe Proust – Law of definite proportions)
Once we determine the mass of water lost, we at the same time determine the mass of remaining part of the salt called the annhydrate. Convert grams of both parts of the hydrate to moles and then get a ratio of how many (moles) by dividing by the lowest number of moles. That ratio is what we will use for the fixed formula!
|
This image was build by X-ray imaging of salt. |
Now it is more complex than the crystal above for NaCl because we have a polyatomic ion in the crystal. The Yellow is the Sulfur attached to 4 oxygens (red). The brown color (i think its brown) is the copper. Notice regular repeating pattern. Its hard but if look inside the crystal there is one Cu per sulfate ion. |
Lets look at the hydrate of the same salt : copper (II) sulphate pentahydrate :
 |
Notice the Dot between anhydrate and water. This dot means “WITH” and not to multiple. Thus there are exactly 5 water molecules for every 1 Cu+2 and 1 SO4-2 in the crystal. |
|
You will notice that water (it has 2 white hydrogen atoms) molecules are situated inside the crystals at particular regions in the crystal in exact ratios. Stiochiometric ratios It is hard but you can see the 5 water molecules per 1 copper ion and 1 sulfate ion. What makes it hard is that the crystal repeats in all directions. The water can be removed from the salt by heating it. |
*Mole Concept Diagram Lesson:
A mole is an abbreviated NUMBER that helps chemistry quantify the actual number of particles (atoms, ions, electrons, molecules, etc.) needed to DO chemistry.
We need an abbreviated number because these microscopic particles ARE SO SMALL that we need a TREMENDOUS amount of them to have a significant amount of matter that we can measure with in the microscopic world. Think how many atoms a mole of Al atoms stacked on each other would be? (Lab 4!) It was over a 100 trillion meters even though each Al atom has 0.286 nm diameter!! Light travels at about 10000 trillion meters per second so this distance would extend way beyond our solar system!
Please remember that the mole is a “how many quantity” that helps us actually Do Chemistry!!! From the mole concept we are able to:
1. Determine the atomic mass of elements (This is how we determined how elements
differed initially!!!).
2: Determine chemical formulas of compounds.
3: Determine the chemical equations of chemical reaction.
4: Predicting quantities like how much of product will we produce given a certain
amount of reactants in a chemical reaction.
5: Predicting quantities like how much of a reactant is needed to make certain amount
of product.
6: Determining the quantities (V, P, T, n) of a gas under changing conditions.
7: Solve Electrolytic Problems (Amperage, how much metal is deposited on cathode, etc.)
8: Determine a concentration (Molarity = mole / Liter of solution) of a solution of ions etc.
9: Finding a quantity that is directly related to the mole.
The key is here is that we are able to use this How many Number not by counting particles which would be impossible but by USING A SCALE! Because we decided to make the Relative Atomic Mass the equivalent in grams that 1 MOLE of every element would measure we can use a GRAM Balance or Scale to measure mass AND THEM convert to moles or vice versa.
*OUR WINDOW INTO THE WORLD OF HOW MANY Particle IS THROUGH MASS
or volume if a gas.
Using moles to answer how many is called Stoichiometry!!!
Stoichiometry works because of the Law of Conservation of Mass.
Because of Antoine Lavoisier and the Modern Atomic Theory by John Dalton, atoms are neither created nor destroyed in chemical reactions and are just rearranged into different ratios of elements in compounds. These ratios are a How Many Value!
Stiochiometry also works because of the Law of definite proportions.
Because of Joseph Proust and the Modern Atomic Theory, each compound has its own unique arrangement of atoms called a chemical formula which results in each unique compound having a unique percent by mass of each type of atom (element) in its molecule. This is due to compound having a unique ratio of atoms in their chemical formulas. Chemical formulas are a How many Value!
Since chemical reactions are a result of atoms, molecules, and ions colliding as individual particles then to calculate the outcomes of reactions we must consider the moles (THE HOW MANY VALUE) of the chemical species.
Law of Conservation of Mass Demonstrations:
10/8 – Tuesday – Homework
*READ NOTES ABOVE
1. Please complete the empiri&molec ditto hydrate combination.pdf worksheet
2. Review with the key below:
3: Please view Lecture 1.3 with the worksheet below.
I will walk you through all questions except number 4.
4. Complete Worksheet Stiochiometry 1 – balance yield.pdf (number 4) and review with key below:
Lecture AP 1.3 – Basic Stoichiometry and percent yield:
5. Precipitation Analysis: Now that we can determine chemical formulas from heating (Lab 5) or from combustion analysis (Analytical Chemistry I – determining chemical formulas.pdf) we can also do so by the number of dry grams of precipitate, as long as we use stoichiometry!
a)Watch Lecture 1.1 Below and and follow along with me with question one as we calculate the Molarity of the individual ions in the solution using stiochiometry.
b) Watch Lecture 1.2 and follow along with me to complete questions 4, and 5 as we use precipitation to and stoichiometry to determine the chemical formulas of the salts (ionic compounds).
c) Complete question 5 on your own and review with the key below. This question puts it all together!
Lecture 1.2: Question 4 and 5 modeled:
End of Tuesday!
10/9 – Yom Kippur – OFF
10/10 – Thursday – period 2
Quiz on Homework/well it was a take-home!
1. Lab 5 – complete lab calculations – final heating was Tuesday..
2. Conservation of Mass Demo (hydrogen balloon demo with and without oxygen
with correct stiochiometic ratio! (Good cake?)
3. Started Analytical Chemistry Quiz (take-home)
Show lattices with and without water with the hydrate posted Tuesday
Did not get to…
period 3/4 –
Quiz on Homework/well it was a take-home!
1. Lab 5 – complete lab calculations – final heating was Tuesday..
2. Conservation of Mass Demo (hydrogen balloon demo with and without oxygen
with correct stiochiometic ratio! (Good cake?)
3. Started Analytical Chemistry Quiz (take-home)
4. Conservation of Mass presentation demo up Hindenburg.
3. Lab 7 – Empirical Analysis of copper Iodide setup – for it to react over the weekend.
Today’s Demo (period 3/4 class) – Thanks Brandon!
2 H2 (g) + 1 O2 (g) —-> 2 H2O (g) + Energy
Which balloon made the best cake?
100% Hydrogen Balloon:
66% Hydrogen with 33% oxygen (2 : 1 ration of Hydrogen to Oxygen):
Older Videos that compare…
Hydrogen and Oxygen demo:
10/11 – Thursday Homework –
1. Please complete the take-home quiz ON the worksheet that was given out today.
2. Complete the Form below that will allow to place your answers into the form below. The form will be on auto-grade to grade your responses. You may submit as many times as you would like BEFORE 9:00 pm. After 9:00pm you will be given 1 more response to submit. The form after 9:00 pm will not be auto-grade. I will send out the final grade with a hand written key at 10:00 pm.
Form: Analytical Chemistry Quiz Take – home.
YOU HAVE A MAX OF 3 SUBMISSIONS BEFORE 9:00 PM!
End of Thursday..
10/11 – Friday – period 2/3
Show lattices with and without water with the hydrate posted Tuesday
1. Homework – Analytical Quiz 1 Form review with key.
2. Hydrogen balloon explosion analysis –
3. Lab 6 – Empirical formula of copper iodide – setup – for it to react over the weekend.
No discussion or note-taking
4. Conservation of Mass demonstration – Challenger and Hindenburg
5. Pringles demonstration – If time permits!
Today’s Pringles can Demo (2nd period):
period 4-
1. Homework – Analytical Quiz 1 Form review with key.
2. Hydrogen balloon explosion analysis –
3. Finish Conservation of Mass Presentation to Zeppelins.
4. Pringles demonstration – If time permits!
5. Lab 6 – Empirical formula of copper iodide – setup – for it to react over the weekend.
6. Lab 6 note-taking.
10/11 – Friday (weekend) Homework:
1. Lab 5 – complete conclusion – Lab is due Tuesday 10/15.
2. Begin the formal write-up of Lab 6 with Google Doc that I will share with you. Everyone has a link to their individual google doc that YOU must use to complete this formal lab write-up.
Objective: To obtain the (empirical) formula of copper Iodide. Remember that copper has 2 different valence quantities as it can be Cu+ or Cu+2 but regardless we are doing a historical Analytical Chemistry experiment WHERE we do not know what the formulas of compounds are!
To determine the percent yield of copper iodide, (once we determine the empirical formula).
Begin the write-up of your first formal lab – Lab 6 – Determination of the empirical formula of copper iodide.
WRITE A BACKGROUND
1) on the properties of Copper metal, iodine, and diffrences in structure and reactivity or anything that might interest you. You could also discuss the product but again you do not know its formula.
2) You may also want to discuss things that you already learned. Will this be a redox reaction? Is it spontaneous?
What is the history of stiochiometry, mole concept, analytical chemistry?
3) This part is open-ended but you must write this Background in a way that it focuses your discussion toward your objective. You are in a way writing this background as prosecuting attorney would present their “opening statement” . You can use any interesting information that you find (You must list your sources as the last page) in your discussion but you must focus it at the end toward the objective at the end.)
You should start with a Title Page:
Lab Title
Student Name
Class
Date
Background Page (label the page as such):
(at the bottom of this page write the objective.)
Background:
Blahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh
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hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh
hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh
hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh
hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh
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Objective:
Write a Procedure Page:
Procedure:
1. Blahhhhhhhhhhhhhhhhhhhhhhh
2. Blahhhhhhhhhhhhhhhhhhhhhhh
3. Blahhhhhhhhhhhhhhhhhhhhhhh
Write a Procedure:
What did you do to accomplish your objectives, Can another researcher follow these steps and repeat the experiment sucessfully?
This section should have each step bulleted!!! You will need to use your notes to figure what we will do in this lab.
The best way to write this so you have a plan of action Tuesday morning is to think how you should mass out the contents of the reaction vessel so that you figure out as a lab group how you go about determining the
i) mass of the copper reacted.
ii) and the mass of iodine reacted.
Isn’t this what we need to get the chemical formula????
Write a Data Page:
Using your objectives, and procedure as your guide you should be able to write a data table of all measured values AND calculated values that is required to complete your objectives.
Add Calculations Page to show all Calculations including All chemical reactions:
You can do this on a piece of paper by hand and then take a picture with your phone and insert it into your google doc.
Add a Sources Page
List all websites that you used in your background or anywhere else in your Lab. You do not need footnotes or use any format like APA. Just list your sources at the end
We will complete the RESULTS, and CONCLUSION pages once we collect the data next Tuesday.
You will complete this write-up with a google doc that I will link to you using the gmail account I have on file for you. There are no exceptions! In this way I can monitor your progress and give you comments.
I will not accept links to your own google doc!
Remember to have access to the linked google doc you will need to logged into google in your browser with the google account (gmail) that you create.
The Formal Lab Write- up must follow the basic format listed in the Lab report Rubric page. There is an example posted there. I am also posting a short video (on the basics of the Lab)
End of week 6!