## Q3: Week 9  – 4/4 – 4/8

4/4 – Monday – A Day – 2/3a Lab, 4

Main focus –

a) To Complete calculations of Ksp Problems

b) To approximate the quadratic for very small Keq values (Ksp, Ka)

Period 2/3, 4:   – Collect the Free Response Question from last Thursday.

1.   Review Last nights Form, selected problems
2.   Model the Ksp Problem – Q vs. K

Equilibrium 4 – Equilibrium constants 2.pdf

Equlibrium 4 – Equilibrium constants 2 KEY.pdf

3. Quadratic Catastrophe introduced
Equlibrium 3 – Equilibrium constants 1.pdf

Equlibrium 3 – Equilibrium constants 1 key.pdf

4. Quadratic Catastrophe avoided – (large and small Keq values)

Circumventing the Quadratic Catastrophe – (large and small Keq values)

Approximating away the Catastrophe”.

Equilibrium 6a Small equilibrium constants.pdf

Equilibrium 6a Small equilibrium constants key.pdf

5. Solving for Ksp value, Common ion effect, Approximating away the Catastrophe with Ksp,

Equlibrium 5 – Ksp.pdf

Equlibrium 5 – Ksp KEY.pdf

THis weekend 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.

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TODAY’s NOTES:  ____________________

If you made a submission last night or this morning then I will give you a 100 on last nights form.  There is no need to add another submission. We went over all aspects of the form that I wanted to cover.

I have Ksp Notes posted in 3rd quarter that go over every type of problem.
Many past students have said they were very helpful.

This homework will change based on what we accomplish in class. Please refresh until this changes.

1.  Please complete – Equilibrium 4 – Question 1 – Ksp problem explained/modeled – lecture below.

Equilibrium 4 – Equilibrium constants 2.pdf

Equlibrium 4 – Equilibrium constants 2 KEY.pdf

2. Complete  Equlibrium 5 – Ksp.pdf worksheet and/or with me with the lecture below: We started this is class. Both classes are at letter (c) of this worksheet. Please follow along with me in the lecture that picks up at letter D.
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.pdf

Equlibrium 5 – Ksp KEY.pdf

3.  Complete Equlibrium 5a – Ksp.pdf worksheet with me with lecture below:

Equilibrium 5a – Ksp continues.pdf

Equilibrium 5a – Ksp continues key.pdf

1: Equilibrium – Question 1 Lecture:

3: Equilibrium 5 worksheet – from c:

2: Equilibrium 5a worksheet review – whole video:

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4/5 – Tuesday – B Day – 2, 3b/4 Lab

Main focus –

a) To complete a Ksp FRQ.

b) To Review the concepts of equilibrium.

Period 2, 3/4 :

1. Hand back collected FRQ that was assigned last Thursday. Reviewed the energy shift question.
Mentioned that the responses were similar to the posted AP key. Was I born 53 years ago?

2.  Reviewed part (d) from Equilibrium 5 worksheet – Temperature and Equilibrium

3. Quick General review of Ksp/equilibrium/Q vs Keq – used New Ksp notes

4.  Ksp TEST – (10 point) AP Question –  1 question part 2 test – (20 minutes)

5.  Review of test and practice with the homework Ksp practice problem.

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TODAY’s NOTES:

I have Ksp Notes posted in 3rd quarter that go over every type of Ksp problem.

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4/4 – Tuesday Homework: –

1.  Review the PRACTICE Test with the keys below if you did not do so in class.

Today’s Test Keys
Ksp Free Response 2010 ques 1 KEY Grodski Board p.pdf

Ksp Free Response Test 2010 ques 1 KEY College Board.pdf

You will have a 2 question (40 minute) part 2 TEST tonight.  A good review would be the following AP questions.

2.  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).

Ksp Practice: Another Ksp problem!
Equilibrium 5b – Ksp practice.pdf

Equilibrium 5b – Ksp practice key (AP Central key).pdf

3. Please Complete the Take-home Test.
These 2 Free Response problems will be collected tomorrow. Please try giving yourself a total of 40 minutes for this test.

Each 10 point Free Response question should take 20 minutes to stay on pace.

I understand that not everyone will do abide by the 40 minute time limit so I would try it for 40 minutes and then add to it after the time limit is up to know how you are doing with the pacing.

Equilibrium 5c – Ksp 2001 2006 Test.pdf

AP grade and Scaled Percentage Score: Example of calculating scaled score:

Let’s say student scores a 6/10 on a 10 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

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)

2: Equilibrium 5a worksheet review – whole video:

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4/6 – Wednesday – A Day – 2/3a Lab, 4

Main focus –

a) To Review the measure of solubility through Ksp’s.

b) To introduce Rate Law

c) To determine the order of a reaction through experimental evidence AND                                determine the best mechanism for an overall reaction.

Period 2/3, 4:

1. Collect the take-home THermo and Ksp Thermo.

2. Review worksheet 5b concepts:

a) 2nd question review – my mistake

b)  Comparing Ksp’s and determining which salt would precipitate first.

RATE LAW Begins:

LAST NEW TOPIC: Rate Law – path function from Reactants to Products

3. Intro to Rate Law – Last New topic! We are very close to being done with the entire course!

a) effective collisions  – collision theory

b)  factors that effect RATE (speed) of reactions (increase the frequency of effective collisions)

i) RATE Law deals with the initial rate of a (spontaneous) reaction BASED on the amount of concentration

Rate Law does not measure spontaneity and spontaneity does not measure Rate Law!

c) Determine the Rate Law based experimental evidence

i) eyeball method vs calculating

d) rate Law predicts the best mechanism by predicting the elementary step that is rate determining.

The slowest step in a mechanism is Rate Determining Step (RDS) !

i) Coefficients = exponents ONLY for single step reactions = elementary reactions = single step reactions

Coefficients becomes orders for Reactants in the RATE LAW EQUATION for ELEMENTARY REACTION ONLY !

ii) Catalysts vs Intermediates.

iii) Determining the mechanism ( a group of elementary steps that overall = the overall reaction) that best represents                          the experimentally determined RATE Law.

Classwork modeling:

Rate Law Rumble 1819.pdf

Rate Law Rumble key .pdf

Kinetics 1 Rate Law .pdf

Kinetics 1 – Rate Law Key.pdf

Rate Law Intro Lecture 1:

Rate Law Intro Lecture 2:

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TODAY’s NOTES:

a) You are to read my notes on RATE LAW that is posted in the 3rd quarter:

http://mrgrodskichemistry.com/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) Rate Law Lecture 1 is what I did today, keeping in mind what you read in the Rate Law Notes.

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4/6 – Wednesday Homework: –

Key To last nights Take-home:

Equilibrium 5c – Ksp 2001 2006 Grodski Key p.pdf

1. You are to read the notes to review skills 1 – 5 (ALL Classes)

2. Please complete the first Rate Law Rumble Worksheet with Rate Law lecture 2 posted above.

PERIOD 2/3 DOES NOT TO COMPLETE THIS WORKSHEET

PERIOD 4 NEEDS TO COMPLETE THIS WORKSHEET Starting at QUESTION 2 –                                                                                Please use the RATE LAW Lecture 2 above to complete.

Rate Law Rumble 1819.pdf

Rate Law Rumble key .pdf

3. Please view the Fast Equilibrium Lecture below and follow along with me following worksheet. (ALL Classes!!)

Kinetics mechanisms – fast equilibrium.pdf

Kinetics mechanisms – fast equilibrium KEY.pdf

3. Please complete the first 2 pages of the Kinetics 2 worksheet  (1984B, 1991B) and review with the key. (ALL Classes)

*If you can use the eyeball method to determine the Rate Law then do so!!!!!

SKIP question C of 1984B

Kinetics 2 – rate law.pdf

Kinetics 2 – rate law KEYp .pdf

3: Fast Equilibrium Lecture:

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4/7 – Thursday – B Day – 2, 3b/4 Lab

Main focus –

a) To Calculate the orders of reaction (when eye ball method does not work)

b) To use stoichiometry in Rate Law questions.

c) To determine the Rate Law through Fast Equilibrium problems.

Period 2, 3/4:

1.  Review the Fast Equilibrium elementary step that helps determine the Rate Law formula for the overall reaction.

2. Review the homework problems – appropriate mechanisms for Rate Laws –

also skill #6 – stoichiometry in rate law

3. When you need to go beyond the eyeball method – Calculating the orders.

* Eyeball method vs. Mathematical method of finding the orders –skill #7

Kinetics 1 Rate Law .pdf

Kinetics 1 – Rate Law Key.pdf

4. catalyst  – Demo

5. Complete 199B of Kinetics 2 worksheets:

Kinetics 2 – rate law.pdf

Kinetics 2 – rate law KEYp .pdf

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TODAY’s NOTES:

Complete RATE LAW Skills from the NOTES:  http://mrgrodskichemistry.com/rate-law-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 #5 – 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

Worksheets worked on so far.

Rate Law Rumble 1819.pdf

RATE LAW SKILLs (in your notes) :  #1, #2, #3, #4, #5, #7

Kinetics 2 – rate law.pdf – (1984B, 1991B)

RATE LAW SKILLs (in your notes) :  #1, #4, #7

Rate Laws from Mechanisms (Optional) Lecture:

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4/7 – Thursday Homework: –

Integrated Rate Law Formulas:
Please follow these instructions. If you do these out of order you will not learn an reinforce the concepts that I want you to review.

1:  Please watch the Integrated rate law derivation lesson below on the derivation of the 0th, 1st, and           2nd Order Integrated  Rate Law formula.

These formulas help us utilize time with changes in our reactant concentrations!
These formulas are integrated formulas (Calculus) and they are needed to link “real time” with actual concentrations (area under curve).  Remember that Rate Law is the Rate from INITIAL CONCENTRATIONS of reactants. That Rate that we have been calculating for changes the instant the chemical reaction starts so it really becomes useless AFTER some time period after time zero.  They utilize concepts of derivative and integrals which many of you have NOT had in math YET! You do not need to use these concepts to answer the following questions, just the formulas:

How long does it take for the reaction to be completed?
How long does it take for the concentration of my reactant to reach a certain value?
Given the time, how much of the reactant remains?
What is the shelf life of the chemical? (how long does it take to decompose?)

2. Read the notes on the new INTEGRATED RATE LAW Formulas – Skill 8 and Skill 9

3: Complete the Form that goes along the video (this will be in auto-reply)

*4: Complete the following worksheet and review with the keys:
Give yourself 40 minutes, these are 2 part 2 questions, then grade. The goal is 7 out of 10.

2005B 2009 Kinetics quiz 2013 with college board and grodski keys.pdf

These formulas are USED WITH TIME!! They are used 2 ways.

1: They can be used to identify the Rate Order By how they are graphed. For instance if you graph a 1st order reaction using the ln[A]t  (ln of concentration of reactant at some time period) in the y axis and the t (time)  in the x axis it will be linear with a negative slope.  If it is not linear with a negative slope then the reactant is not 1st order.

See the reference table below.

2: Once you identify the whether the RATE ORDER is 1 or 2 use the correct integrated rate law equation to solve either the time (t), initial concentration [A]0 , concentration of reactant after some time[A]t ,
or the rate constant, k.

What this lecture describes is the mathematics  (Calculus ) needed to solve for or Link Time with remaining reactants.  These important derivations will derive our Integrated Rate Law Formulas that are given to us in our reference tables.   They help us identify the order (or exponents) of our reactants in our Rate Law Equation just by graphing the changes of concentrations of the reactants in time during a chemical reaction.

Here they are in our reference tables: It is usually very helpful to utilize these equations when you arrange them into a linear equation.   1st Order:                   X   –>  Y                                         R = K [X]1                                                                   ln[A]t – ln[A]0 =  -kt                                ln[A]t  =   -kt   +    ln[A]0                                 y      =    mx  +      b                                         (negative slope)    2nd Order:                X  +   X  –>  X2                                            1   –   1     =  kt                                  [A]t    [A]0                                            1     =  kt   +    1                                  [A]t                [A]0                                                 y     = mx  +   B                                                                                (positive slope)

1: Integrated Rate Law formulas:

3 : Integrated Rate Laws Formulas Form:

C

Derivations of the 0th, 1st, and 2nd order Screencast lecture – optional lecture

Catalyzed decomposition of hydrogen peroxide demo – lowering the Ea with a mechanism!

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4/8 – Friday – A Day – 2/3a Lab, 4

Main focus –

a) To identify the order of a reaction based on its graph vs time

b) To identify the order of a reaction based on its half- life.

Period 2/3:

1. Integrated Rate Law Review: (Homework review)

2005B 2009 Kinetics quiz 2013 with college board and grodski keys.pdf

IF you need help with the math using the integrated equations please use the following video.

2009 Review video of the Integrated Formula question from last night.

2. Review Letter C question that was skipped in 1884B in Kinetics 2 worksheet.

Kinetics 2 – rate law.pdf

Kinetics 2 – rate law KEYp .pdf

3. Iodine Clock Reaction –

– Looked at the mechanism in the Rate Law presentation to explain the “clock” reaction.

– Viewed the Iodine clock Test video and observed the first 2 tests to prove the iodate ion has an order of 1.

– Used that to create a demo with synchronous clocking with different concentrations of iodate.

4.  Half life derivations – differences between the 0th, 1st, 2nd order half life formulas.

Rate Law Presentation:

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TODAY’s NOTES:

Reference Table: This is the first order integrated formula.         This is the second order integrated formula. There is no zero order integrated formulas on the AP. This is the Arrhenius equation that ties activation energy ( Ea) and temperature to the rate law constant.

It is usually very helpful to utilize these equations when you arrange them into a linear equation.

1st Order:                   X   –>  Y

R = K [X]1

ln[A]t – ln[A]0 =  -kt

ln[A]t  =   -kt   +    ln[A]0
y     =    mx  +      b
(negative slope)

2nd Order:                X  +   X  –>  X2

–       =  kt
[A]t    [A]0

=  kt   +    1
[A]t                [A]0

y     = mx  +   B
(positive slope)

Iodine Clock Reaction and Lab:

Iodine Clock Demo.  Knowing what the order of the Iodate ion from the lab above is how did set this up?

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4/8- Weekend Homework: –

1. Complete a 5 question MC form on rate law.

Catalysts and Activation Energy (Ea = Activation Energy)
The Arrhenius equation calculations are not on the AP but the concepts of how the k (Rate law Constant, like the equilibrium constant) is related to temperature.

2.  Please watch the Lecture on the derivation of the half – life formulas and lecture on the
Activation Energy, Ea.

3. Complete the form below that is based on the 2 lectures.

4. Complete a 2 question FRQ (rate law and KSP).

Kinetics (rate law),Ksp Free Response, 2004B, 2009 FRQ .pdf

1 : Rate Law MC Questions Review Form.

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2 : Half Life Derivations of the oth, 1st and 2nd order

2 : Activation Energy (Ea) Lecture.

3: Half Life / Arrhenius/ Ea Form 21-22

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