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Archive – Q3 week 8 – 19-20

Week of 3/23 – 3/27 – PLEASE REFRESH EVERY TIME!

3/23   – Monday – Meeting at 10:00am today
 
Link to today’s recorded meeting: 
 
Still working on Monday..
1. Update from AP Central:  
 
        a) Your AP Chemistry exam is on and it will be a 45 minute free – response test that you will  
             take online at your home.
 
        b) It will have 2 units omitted (breaks my heart!)
 

 

 
        c) You will given the choice of 2 dates to take it. Early  in April or later in May,
 
        d) Our plan….
 
        e) equilibrium problems..
 
2.  Today’s period 2 lecture – Completing review of Non-Spontaneous Form ( 5 – 10 )
      Complete review of the Thursday’s Form ( 6 – 10 ) which will review the concepts of 
     ∆Gº, nonstandard ∆G with Q, and Keq.
 – I review the LeChateliers principle Key, we did this worksheet earlier in the year.
 
LeChateliers principle worksheet KEY 2012 p.pdf
View Download
 
∆Gº will determine the position of the Keq (or its value).
 
– Slide 60 – 62 in Thermodynamics Presentation
3.  View Period 3 lecture: Le Chateliers Principle with demos – Q vs Keq
 
     a) Le Chatelier’s Principle (Q vs. Keq) with solutions, Cobalt complex Lab Demo
     b) Le Chateliers’s Principle with Heat,  N2O4  ——>  2 NOdemo
             i) Heat changes the Keq position. 
           ii) Derivation
 
We know that increases and decreases of Temperature CHANGE Keq position or value.  An Endothermic Reaction is favored in higher temperatures and an Exothermic Reaction is favored in lowered temperatures. We understand this by setting our standard ΔG formulas together and looking at the ln K equals (specifically at the ΔH part of the equation).
    
Today’s Period 3 Lecture: Le Chateliers Principle with demos – Q vs Keq
 
 
4)  LeChateliers Principle with using the homework worksheet and ΔG = ΔG° + RT ln Q, 
            reviewed how temp and pressure are a bit different U diagrams!!!
 
 Equlibrium 2 – Gibbs and lechats key.pdf. 
This worksheet reviews the important skill of calculating Keq from ∆Gº = – RT ln Keq

5) Live review of 

 
1) Fizz Keeper
2) Question 1, equilibrium 4, Ksp question.
3)  Question 2, equilibrium 4, “the Quadratic Catastrophe
4)  Equilibrium 6a – Small Equilibrium Constants, “Approximating away the Catastrophe”.
Equilibrium 4 – Equilibrium constants 2.pdf
View Download
Equilibrium 4 – Equilibrium constants 2 KEY.pdf
View Download
Equlibrium 6a Small equilibrium constants.pdf
View Download
 
Equlibrium 6a Small equilibrium constants key.pdf
View Download
 
      
Derivation with Keq, Enthalpy and Temperature : (optional)

YouTube Video

Last night we introduced a new Keq that we call Ksp when we look at ionization reactions:
 
 AgCl(s)  <----->     Ag+(aq)   +    Cl(aq)
 
Keq or Ksp = [Ag+][Cl]
 
All ionization reactions have the same general reactions so all the equilibrium expressions look the same. Its called a solubility product (Ksp) instead of Keq because its Ksp depend on the product of the ions in solution. The more ions in solution at equilibrium the higher the Ksp thus the more soluble the salt is.  We can measure solubility based on equilibrium constants. We do not consider the AgCl (s) in the equilibrium expression because it is a solid, which has no dilution ability.
 
3/ 23 HW:  1 part 2 Question Test (Ksp) – 20 minutes Tuesday!
 
Everyone takes this Tuesday!! 
PLEASE REFresh AS THIS WILL CHANGE BASED ON WHAT WE COVER IN CLASS TODAY!
 
I did cover the concepts of 1,2, and 3 in our live session today.  Feel free to move on to 5, and 6!

 

1.  Please complete – Equilibrium 4 – Question 1 – Ksp problem explained/modeled – lecture below.
       Period 2/3 did this as classwork!
 
Equilibrium 4 – Equilibrium constants 2.pdf
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Equlibrium 4 – Equilibrium constants 2 KEY.pdf
View Download
 
2.  Please complete Equilibrium 3. – Question 3 – Backside – Quadratic Catastrophe Lecture below.
        Just watch me review this problem. Please.
 
Equlibrium 3 – Equilibrium constants 1 key.pdf
 
Equlibrium 3 – Equilibrium constants 1.pdf
View Download
 
3.  Please complete Equilibrium 6a – Circumventing the Quadratic Catastrophe Lecture.
Lecture below.  You should work with me to complete this equilibrium problem!
 
Equlibrium 6a Small equilibrium constants key.pdf
View Download

 

4: Complete  Equlibrium 5 – Ksp.pdf worksheet and/or with me with the lecture below:
If you feel that you are on your way feel free to complete without video lecture and review with the key below.  YOUR ARE TO COMPLETE LETTER D in the question. In the video I say not to but please complete it and review with Key.
 
Equilibrium 5 Lecture: see below 
 
Equlibrium 5 – Ksp KEY.pdf
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Equlibrium 5 – Ksp.pdf
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5:  Complete Equlibrium 5a – Ksp.pdf worksheet with me with lecture below:
Equlibrium 5a – Ksp continues.pdf
View Download
 
Equlibrium 5a – Ksp continues key p.pdf
View Download

Classwork Lecture 1: Equilibrium 4 – question 1 use the backside for space.
Classwork Lecture 2 : The Quadratic Catastrophe lecture – 
Classwork Lecture 3: Circumventing the Quadratic Catastrophe
Start this at 12:00 – Approximation Lecture – 
Equilibrium 5 Lecture: 
 
Homework Lecture: Equilibrium 5a Lecture: 
 
 You are studying for AP with this work!
 
End of Monday…

3/24  – Tuesday –  *Meeting at 9:00 to review Ksp problems                                  
                                   *Meeting at 10:00 to take Ksp Free Response Test
 
LINK to the recorded video from 9:00 meeting (review of Ksp problems):
 
*I have notes that are posted in their separate page (in the 3rd quarter) for Ksp! Every skill that you need in Ksp is posted is reviewed in here. Those that like a textbook. I have posted my version there.
 
 
1:  Quick General review of Ksp/equilibrium/Q vs Keq – used New Ksp notes
 
2:  Ksp TEST – (10 point) AP Question –  1 question part 2 test – (30 minutes) 
                       – I have to give you time to upload and paste your responses.
                                                             
3. Review of test with key/started Equlibrium 2 – Gibbs and lechats.pdf – 
  
I will collect, grade, and email back out your AP graded free response test with a Scaled percentage grade TODAY!
I will also post a key in Power School.
 
 
3/24 – Tuesday Homework:  Tomorrow you will have a 40 minute test that consists of 2 part sections
                                                           1 will be a Ksp question and the other will be a thermo question.
 
** I just put the key from Last week’s Thermo’s free response test in Power School for your Thermo review.
 
1.  Review the PRACTICE Test with the keys below. 
I will go over the PRACTICE Test with you in terms of how to score the practice AP Question, if you do not understand form the printed Rubric posted below.
 
Also please take a look a my notes section for Ksp (equilibrium problems for ionization reactions).
 
You will have a 2 question (40 minute) part 2 TEST tomorrow.  A good review would be the following AP questions.
 
2.  Complete the THermo  worksheet below (Thermo Practice) and review with the key.
3:  Please complete Equilibrium 5b – Ksp practice.pdf  and review with key below.
      I made a lecture for this problem below!
 
***In Question (b) ii  of Equilibrium 5b – Ksp practice.pdf I did not finish the sentence: 
Calculate the minimum concentration of F(aq)  necessary to initiate precipitation of the salt selected in part (b)(i).
 
Today’s Test Keys
Ksp Free Response 2010 ques 1 KEY Grodski Board p.pdf
View Download
 
Ksp Free Response Test 2010 ques 1 KEY College Board.pdf
View Download
Practice Ksp Test Blank and Keys
Equlibrium 5b – Ksp 2010 ques 1.pdf
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Equlibrium 5b – Ksp 2010 ques 1 key p Grodski Board.pdf
View Download
 

Equlibrium 5b – Ksp 2010 ques 1 key College Board.pdf
View Download

Thermo Practice:
Equlibrium 2 – Gibbs and lechats.pdf
View Download
 
Equlibrium 2 – Gibbs and lechats key.pdf
View Download
Ksp Practice: Another Ksp problem!
Equilibrium 5b – Ksp practice.pdf
View Download
 
Equilibrium 5b – Ksp practice key (AP Central key).pdf
View Download
 
Lecture on the Ksp Practice – Equilibrium 5b – Ksp practice.pdf:
End of Tuesday..

3/25 – Wednesday –   Meeting today at 9:30 to discuss yesterday’s free response test
                                         Today’s Free response test is 10:00
–  I emailed everyone’s test last night – 
 
AP grade and Scaled Percentage Score:
 

 

Example of calculating scaled score:
 
Lets say student scores a 6/10 on a 1o point free response question.
 
6/10 = 60% —-> AP grade of 3  because it falls between 44 – 63 in the rubric above.
 
Now I decided an AP Grade of 3 is equal to an 80% of a regular test grade at the minimum and that an AP Grade of 4 is equal to a 90% of a regular test grade at the minimum.
Now a score of 60% of the raw grade is a very high AP grade of 3 as it close to the 63 – 64 cutoff point for an AP Grade of 4 so the scaled percentage should reflect a score closer to the minimum regular test grade of 90% for a AP Grade of 4.
 
                                                    AP Grade of 3  ———————->  AP Grade of 4
on regular test =                              80                                                             90
Raw grade AP Rubric=                 44                                                              63                                                  
 
Actual Graded Raw grade =                                                     60
 
Since it is closer to to the 63 cutoff for a 90 I need to calculate what percentage the actual graded raw grade is from the range of 44 – 63:
 
                                                                             60  –  44    =   .84 (of the range from the minimum)
                                                                             63  –  44
 
So a raw grade of 60 is .84 the from the minimum value of 44.  NOW since I decided that an AP grade of 3 is equivalent to an 80 on a regular test and an AP grade of 4 is equivalent to an 90 on a regular test the range of points in a regular test between the 2 AP grades is 10: 90 – 80 = 10
 
So to find how many points I add to the minimum regular test score for the raw grade of 60:
 
                                                                                .84   x   10 =  8.4 
 
                                                            And the actual test grade is now:  80 + 8.4 = 84 (Power school grade)
 
 
1. Review of Tuesday’s test.
2. Ksp and Thermo test –  2 question part 2 test – (45 minutes)
      two 10 point part 2 AP Questions.
                               
3/25 –  Homework: 
 
1. Please review your test with the key that will be posted later.
    The faster you look and review the stronger the connection you will make with the material.
Today’s Ksp and thermo Free Response Test Keys: posted after test
College Board Key and grading Rubric:
 
Equlibrium 5c – Ksp 2001 2006 college board key ques 1 and 2.pdf
View Download
 
Grodski Board Key:
Equlibrium 5c – Ksp 2001 2006 Grodski Key p.pdf
View Download
2. Please complete the following form which are past AP multiple choice questions on equilibrium. 

Equilibrium MC Review Form 1a 1920

 

 

End of Wednesday..


3/26 Thursday   – We will not Meet today. 🙁
 
1. Review Ksp and Thermo test –  with your graded test against the College board’s key. I will have your tests graded and emailed back you today.  
 
Today’s Classwork:
2. Intro to Rate Law – Last New topic! We are very close to being done with the entire course!
 
    a) You are to read my notes on RATE LAW that is posted in the 3rd quarter:
        https://sites.google.com/a/whbschools.org/grodski-ap-chemistry/3rd-quarter/rate-law-notes                                                                       
*You are to read my notes up to and including skill 5!  I have worked really hard to write a complete chapter in RATE Law that I hopefully is clear and logical and breaks down every skill you need to learn.
RATE LAW looks daunting at first but trust me everyone loves rate law once you let it sink in.  PLEASE do this before you view todays class lectures.  The Lectures will make MUCH more sense.
    b) Please view Rate Law Lecture 1 keeping in mind what you read in the Rate Law Notes.
Rate Law Intro Lecture 1:
 
Rate Law Presentation that I used in the lectures:

Rate Law

 
Rate Law Intro Lecture 2:  Please use this with your homework
3/26 – Thursday –  Homework: 
You really need to view the RATE LAW NOTES and lecture 1 Before moving on to the homework!
 
1.  Please watch the Rate Law intro Lecture 2 above and follow along with the 
     Kinetics honors rate law rumble –  worksheet and complete Kinetics honors rate law rumble worksheet 
     (questions 2 and 4).
___________________________________
RATE LAW SKILLs (in your notes) :  #1, #2, #3, #4, #5, #7
 
Rate Law Rumble 1819.pdf
View Download
 
Kinetics honors rate Law rumble key p – pdf.pdf
View Download
 
 
2: Please complete 2005B problem in Kinetics 1 – rate law.pdf  worksheet (first side).
___________________________________
RATE LAW SKILLs (in your notes) :  #1, #4, #7
Kinetics 1 – rate law.pdf
View Download
 
Kinetics 1 – rate law key.pdf
Complete RATE LAW Skills from the NOTES:
Skill #1 – Identify the orders of the reaction from the experimental evidence – Eyeball method
Skill #2 – Determining catalysts and intermediates in mechanisms
Skill #3 – Determining Rate Law from mechanisms or evaluating the best mechanism
Skill #4 – Determine the rate law constant with correct Units
Skill #– Calculate the Rate for the initial concentrations that are not in the experiment.
Skill #6 – Determine the Stoichiometric loss of reactants to gain of products
Skill #7 – Solve for the Rate Law orders without EYEBALL method
Skill #8 – Solve for the Rate Law orders with Graphs 
Skill #9 – Solve for time, concentration, or using integrated Rate Law formulas
End of Thursday.

3/27  – Friday  –  We will meet today at 10:00 am!
 
Link to today’s recorded meeting: 
1. Review of Ksp and Thermo Free Response test.
2: Rate Law Basics – from New Rate Law Notes – 
 
     -Factors that affect Rate of reaction – demos
     a) What Rate Law is not (not a measure of spontaneity) – a pathway from the initial to final state-
      b) Coefficients becomes orders for Reactants in the RATE LAW EQUATION
           for ELEMENTARY REACTION ONLY!
      c) Basic mechanism – slowest step is Rate Determining Step (RDS) –  The Elementary step in a reaction      
           mechanism that is the RDS defines the RATE LAW.
 
2: Mechanisms – did not get to the fast equilibrium mechanism – will complete as part of the homework.
 
Kinetics 2 – rate law.pdf
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Kinetics 2 – rate law KEYp .pdf
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Kinetics mechanisms – fast equilibrium.pdf
View Download
 
Kinetics mechanisms – fast equilibrium KEY.pdf
View Download
Today’s Demos:
 
A catalyst lowers the activation energy (Ea) by moving the reaction in a different pathway or MECHANISM that normally the reactants would not travel through.  A lowered activation energy will increase the rate of reaction as more energy is available for effective collisions!
 
I am using an iodine ion catalyst that creates the mechanism listed in last nights homework for the hydrogen peroxide decomposition.
 

Increased Pressure increases rate the Rate of reactions (gases) by increasing more frequent collisions!

Surface area affects Rate of reactions by exposing more atoms or molecules to increases collisions!
Temperature affects rate of reaction in light sticks:
A rate of reaction demo with liquid oxygen:

How temperature affects the rate of reaction (or the rate constant!):

 
Knowing that the iodate ion was 1st order from today, how did I set this up?
Today’s Virtual Lab:
3/27  Friday-  Homework:  – There will be a 10 point Rate Law Free response Test Monday
Monday’s Rate Law Free Response Skills:
Skill #1 – Identify the orders of the reaction from the experimental evidence – Eyeball method
Skill #7 – Solve for the Rate Law orders without EYEBALL method
Skill #2 – Determining catalysts and intermediates in mechanisms
Skill #3 – Determining Rate Law from mechanisms or evaluating the best mechanism
Skill #4 – Determine the rate law constant with correct Units
Skill #5 – Calculate the Rate for the initial concentrations that are not in the experiment.
1.  Please watch the video on how to deal with the “fast equilibrium” mechanism. You will Complete the Kinetics mechanisms – fast equilibrium.pdf with me. 
 
2: Complete the Kinetics mechanisms – fast equilibrium.pdf  worksheet (backside) and review the key.
3: Complete 1st page of Kinetics 2 packet specifically, 1984B. Omit questions c) and d) and review with key above.
4: Please complete the 2nd page of the kinetics 2 worksheet  (specifically  1994 B worksheet) and    
      review with the key.
 
5.  Watch a classroom lecture of me reviewing the homework.
 
Kinetics 2 – rate law.pdf
View Download
Kinetics 2 – rate law KEYp .pdf
View Download
Kinetics mechanisms – fast equilibrium.pdf
View Download
 
Kinetics mechanisms – fast equilibrium KEY.pdf
View Download
Fast equilibrium- Lecture: 
Lecture of Mr. Grodski reviewing this weekend’s homework:
End of Week 8..