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Q1: Week 2  – 9/6 – 9/9

                                                                                                                                                                                    Jump to:  Tuesday,  Wednesday,  Thursday,  Friday 

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                                                                                                                                                                                                                                                       Jump to:  Tuesday Homework
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 9/6 – Tuesday – A Day – 2/3a Lab, 4 single –         

Main focus– 
 
    a) To apply Coulombs Law in Solubility and review the concept of spontaneity.
     
    b) To review how to write a half reaction and identify a redox reaction. 
 
    c) To introduce the concepts of voltage and Net Potentials in redox reactions.

 

Period 2, 4:

 
1. Review of Summer Institute Summer Institute and Summer Assignment Connections Form 
    used key below to review last question.     

 

Summer Assignment Connections Key – 22-23 .pdf

2. Solubility into Coulombs Law – Questions 5 & 6.

– Charge Density and Table F in the Regents Chemistry Table

– Spontaneity in chemical reactions – pathways allowable by nature (universe)

3.  Writing Half  Reactions from the Sodium and Chlorine Demonstration – Notes from lecture this weekend.

4.   Half reactions practice – worked on Redox 4 – Net potentials Demonstrations worksheet

– half reactions and agents. 

– net potentials —-> help us determine spontaneity 

Today’s Worksheets:

Redox 4 – Net potentials Demonstrations worksheet 1213.pdf
View Download 
 
Redox 4 – Net potentials Demonstrations worksheet 1213 key p.pdf
 
Standard Reduction Potential Table.pdf
View Download

 

5.  Standard Reductions Table Basics lesson: – DID not finish this.

 

        E0cell = NET VOLTAGE! (from redox reaction)
 
                       positive voltage = spontaneous = there IS a pathway that the universe allows = IT REACTS!
 
                      negative voltage = non spontaneous = there is a NO pathway that the universe allows = IT doesn’t
                                                                                                  under the current set of conditions 
Electron transport system, F vs O2 , S vs O as final electron acceptor, 
Na vs Cu for pipes, Gold inactivity
spontaneity and free Energy/ pathway of energy/ voltage
 
                                                  Cu in SnCl2  Reaction vs.  Sn in CuCl2

 

Today’s Net Potential lesson:  using the demonstration above. – We did not finish this today!

 

Spontaneous Reaction NaCl demo used for class lesson :

Period 2 – 2/3a Lab –                                                                                                                                       
 – I continued with the Net potential lesson, we needed the time to catch up from the loss of the period from the assembly last week.   
 
Lab one starts Thursday!    
 

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9/6 – Tuesday Homework: –

1. Please view the Danielle Cell Lecture posted below. You may need to take notes.

2. Please make 2 submission to the  Daniell Form (activity) below.    You have one more submission as I will review this lesson Live in class tomorrow.  You need to get as much as you can from this video and I will present it again tomorrow and take any questions!  We do this together! 

If you do not make your 2 submissions tonight then you will only have one for tomorrow!

1 – Daniell Cell lecture:  This is for tonight homework. .

I will spend a lot more time explaining The Standard Reduction Table tomorrow! That is the table to my right in the video. I need you to get as much out of the lecture below as possible! 

        E0cell = NET VOLTAGE! (from redox reaction using the standard reduction potential table.
 
  positive voltage = spontaneous = there IS a pathway that the universe allows = IT REACTS!
 negative voltage = non spontaneous = there is a NO pathway that the universe allows = IT                                                   doesn’t under the current set of conditions 

 

 
2 – Daniell Cell lecture: Form: 
       This form is based in the lecture above. You have 2 submissions tonight. It will be on auto-reply.

 

                                                                                                                                                                                                                                                     Jump to:  Wednesday Homework ________________________________________________________________________________

9/7 – Wednesday – B Day – 2 single, 3/4 Lab                  

Main focus –

 
     a) To better understand the Standard Reduction Potential Table and apply in to 
          determine the Net E0cell – electromotor force (volts) for chemical reactions.
     
     b) To review concepts of spontaneity, voltage, amperage through the Standard
          Reduction Table.
     
     c) Review the concepts of the Daniell Cell (battery/voltaic cell) that includes
          spontaneity. 

 

 
1. Review of Yesterdays demo that (posted below) that reviews the positive and negative volts. 
       
Standard Net Potential (E0 cell) = voltages = potential difference = joules/C = Energy to move 
                                                                                                                                                              charge                         Voltages measure a pathway of electron flow (redox reactions) = Spontaneity = pathway!                                                                                                                                                                                                                              A pathway allowed by nature is driven by an increase in Entropy. Entropy is the measure of the dispersion on energy from a concentrated source to a less concentrated source.                                                                                                                                                                                                                                                 This is the reason why Heat flows to Cold! or Stored Energy is eventually released OR                     Why a battery dies! Passive Transport!  Entropy gives us Free energy!!! Is there really 
    renewable energy?
 
E0cell = NET VOLTAGE! (from redox reaction)
 
                       positive voltage = spontaneous = there IS a pathway that the universe allows = IT REACTS!
 
                      negative voltage = non spontaneous = there is a NO pathway that the universe allows = IT doesn’t
                                                                                                                                              under the current set of conditions 

Today’s Worksheets:

Redox 4 – Net potentials Demonstrations worksheet 1213.pdf
View Download 
 
Redox 4 – Net potentials Demonstrations worksheet 1213 key p.pdf
 
Standard Reduction Potential Table.pdf
View Download

 

2. Daniell Cell Review: I reviewed the concepts of the an example of a voltaic cell. Video posted above in  Tuesday’s Homework reviews this lesson but today I will incorporate the concepts of spontaneity into it. It will include concepts from this weekends lecture.

I use a Danielle Cell demo to illustrate these concepts.

 

_________ 
3b/4 Lab – 
 
LAB Activity 1 – Making of batteries (voltaic or galvanic cell) – last 15 minute. In this Lab each person will make a pair of voltaic cells that if successfully created will power a 3 volt transistor radio.
 
                        a) Make one voltaic cell and identifies anode, cathode and tested voltage.
                            Identified the spontaneous process with positive volts
                            wrote half reactions, identified ox and red agents.
 
LAB 1 – Voltaic Cell.pdf
   

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9/7 – Wednesday Homework: –

1. Please make 1 more submissions for a the Daniell Form (activity) posted above in Tuesday’s post.  Please do so ONCE class is over,

2.  Read my *Connections NOTES –  POSTED IN This weeks notes (link: week 2 notes).

3. Watch the Voltaic Spontaneity lecture 2017 lecture below:
     
 4.  Complete the Voltaic Spontaneity Form.  You have 3 total submissions for this form this and it is on auto-reply so make sure you have the correct email entered.

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3 – Voltaic Spontaneity lecture:  This is for the homework form below..

 

 
4 – Voltaic Spontaneity Form:  This form is based in the lecture above.

 

 End of Thursday!

 

                                                                                                                                                                                                                                                           Jump to:  Thursday Homework
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9/8 – Thursday – A Day – 2/3a Lab, 4 single

Main focus –
     a) To link the concepts of spontaneity to the voltaic cell.
     
     b) To teach the concept of Le Chatelier’s Principle. 

 

1. Review the Voltaic Spontaneity HW Form- with key
     Skills:   Solubility, Spontaneity, Equilibrium, 
                  How concentration of soluble ions in a voltaic cell affect its voltage.
Daniell Cell Lecture Form 22-23 – Key p.pdf

     

Daniell Cell Lecture Form 22-23 – Key p.pdf                                                                                              View Download

Voltaic Spontaneity Form – 22-23 Key p.pdf                                                                                                             View Download

 2.  NO2 and N2O4  ampule demo with heat, viewing the ampule as equilibrium.

    Manipulating the spontaneity with heat, in phase changes, adding salt to ice
 
3.  LeChateliers Principle/ with worksheet
 
     LeChateliers principle worksheet p.pdf
     View Download
 
    LeChateliers principle worksheet KEY 2012 p.pdf
    View Download
 
4.  Re-vist the Classroom Daniell cell and predict voltage 
     by manipulating concentration of free ions

_________ 
2/3a Lab – 
 
LAB Activity 1 – Making of batteries (voltaic or galvanic cell) – last 15 minute. In this Lab each person will make a pair of voltaic cells that if successfully created will power a 3 volt transistor radio.
 
                        a) Make one voltaic cell and identifies anode, cathode and tested voltage.
                            Identified the spontaneous process with positive volts
                            wrote half reactions, identified ox and red agents.
 
LAB 1 – Voltaic Cell.pdf
   

 

LeChateliers Principle Notes:

Notice that concentration of the NO2 is large initially and decreases as the reaction proceeds.

Notice the initial concentration of N2O4 is zero (it has not been made yet) and increases as the reaction proceeds.

Both NO2 and N2O4 eventually level out and at this point equilibrium has been reached!

If the rate of 2NO2 combining to make N2O4 (forward reaction) is as fast as rate of N2O4 decomposing into 2NO2 (reverse reaction) then the concentration of both chemicals become CONSTANT at equilibrium.
 

At point C, there 100% NO2  and 0% N2O4  thus there is no competing reaction because there is no NO2 to combine to make the N2O4.  The reverse reaction is at it maximum spontaneity and the forward reaction is at its minimum. There is a Shift in the reaction to move in the reverse. Over time its spontaneity will steadily decrease until it reaches the point of equilibrium and the “death of the reaction”.

Notice that the equilibrium position is at the bottom!! This is where the death of the reaction or where there is ZERO Spontaneity or No more release of energy into the Universe.

                                     ΔSuniverse = 0

At point A we have 100% NO2 and 0% N2O4.  At this point there is tremendous pathway to go forward!  There is No competing backwards reaction!! The reverse reaction is impossible here.  It so spontaneous in the forward that the reverse is impossible!

At point B, there is 60% NO2 and 40%  N2O4.
Here we have a competing reaction reverse reaction thus the forward reactions is not as spontaneous and the reaction is getting closer to its death.  The reverse reaction is still not as spontaneous as the forward but it is closing in, thus the overall Net direction is still forward but this pathway is not nearly as great as point A. 

Dissolving of a soluble salt :  Water can compete with the Coulombic attractions of ions in a salt.

 

LeChatelier’s Principle Lesson :  If you need to review this..

 

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9/8 – Thursday Homework: – 

1. Complete LeChateliers Principle worksheet (front side) given out in class 
    and review the key below:

 

     LeChateliers principle worksheet p.pdf
     View Download 
 
    LeChateliers principle worksheet KEY 2012 p.pdf
     View Download
 
2. Please view my Demo video that was today’s demo.  It was a glorious fail for my period 4 class so I wanted to share this with everyone.  
 
3.  Please complete Intro Voltaic Cells Worksheet 2 
     BUT PLEASE Complete QUESTION 2 ONLY!!

 

      THIS IS THE SIDE THAT HAS NO TITLE. Sorry both sides are numbered 1!
o
      Intro Voltaic Cells worksheet 2 – skills.pdf
     View Download
4.  Review question 2 (the one you just did) with the key below.
 
      Intro Voltaic Cells worksheet 2 – skills Key p.pdf
      View Download
 
5.  And/or you can follow along with me going over Question 2 with lecture below.
     Intro Voltaic Cells worksheet 2 – skills.pdf  worksheet Lecture:  
 

4: Today’s Demo: Literally!

 

 

5: AP Chemistry Voltaic Cell Concepts Review worksheet 2 Video:  

Click on START AT 23:12 to view the video below to start directly at question 2.

 

 

Today’ lesson:

 

 

                                                                                                                                Jump to:  Friday Homework _________________________________________________________________________________________________________________________

9/9 – Friday – B Day – 2 single, 3b/a Lab 

Main focus –

a) To identify the voltage change in a voltaic cell due to Le Chatelier’s Principle with changes in the concentrations of ions in half cells, specifically when a precipitate is made.  

b) To identify the precipitate in a net ion equation using the solubility rules or concepts. 

1. Quick Review of the LeChateliers principle worksheet p.pdf – Keep connecting to the U diagram
m
LeChateliers principle worksheet KEY 2012 p.pdf
View Download

 

2.  Revisit the Classroom Daniell cell and predict voltage: 
 
     a) Diluting the Reduction half cell ( Cu/Cu+2 ) or Blue One with water.
 
    By adding water to the Cu+2 ion solution (molarity) decreased and thus the 
    Voltage Decreased!!!!   
 
Explained in terms of LeChatelier’s Principle and Spontaneity!
 
                                                              Stress          Response  
   
                                            ⬇︎ [Cu+2]          ⬆︎[Cu+2]
   
We added more water to dilute and lower the          The reaction responds to undo the stress by 
concentration of copper ions.                                         moving toward equilibrium (in the reverse).
 
*We were lowering a reactant by dilution and the reaction reacted by making more of the reactant to get to equilibrium.  
 
                                                  Zn0  (s)   +    Cu+2  —–>   Zn+2    +     Cu0
                              Stress:                                      decreases
                        Response:                       <—————– Shift =  voltage drop! 
                                                                                  (lowers spontaneity of forward reaction)            The reverse is favored more (than it was originally) which LOWERS the forwards reactions 
            pathways or spontaneity, which results in lowering the voltage!
 
    In terms of spontaneity:
 
          b) Diluting the Oxidation half cell (Zn/Zn+2) or clear bleaker with water.  
 
By adding water to the Zn+2 ion solution (molarity) decreased and thus the 
    Voltage Decreased!!!!   Explained in terms of LeChateliers Principle and Spontaneity! 
 
                                                              Stress          Response  
   
                                             ⬇︎[Zn+2]          ⬆︎[Zu+2]
   
We added more water to dilute and lower the          The reaction responds to undo the stress by 
concentration of zinc ions.                                              moving toward equilibrium (in the reverse).
 
   
                                                  Zn0  (s)   +    Cu+2  —–>   Zn+2    +     Cu0
                                Stress:                                                       decreases
                       Response:                       Shift ———————> = Voltage increase!
                                                                               (increases spontaneity of forward reaction)
 
    We can decrease the concentration of dissolves ions (aq) another way besides adding water. We can precipitate out an ion if we add another salt that delivers an ion that will make an insoluble salt.
The homework for the weekend will have this concept. 
 
3.  Precipitation reaction demo – Double replacement reactions or precipitation reactions- 
     Net ion reaction written to eliminate spectators!
 
Net Ion Reaction Intro – Precipitation 1920.pdf
View Download
 
    A) Wrote the precipitation reaction between lead (II) nitrate and potassium nitrate.
          We used the following worksheet:
 
    B) Particular Diagrams
    C) Identified the precipitate.
    D) Performed the demonstration.
h

Today’s demonstration:

 

 

Today’ lesson:

 

3b/4 Lab – 

LAB Activity 1 – Making of batteries (voltaic or galvanic cell) – In this Lab each person will make a pair of voltaic cells that if successfully created will power a 3 volt transistor radio.
                   
LAB 1 – Voltaic Cell.pdf

                           a) Made one voltaic cell and identifies anode, cathode and tested voltage.

                            Identified the spontaneous process with positive volts
                            wrote half reactions, identified ox and red agents.

 

                           b) Completed the diagram, conclusion questions, and reviewed errors for the writing of the 
                                conclusion

&nbsp

.  Started answering questions 5, 6, 7, 8 from Lab:
 
    question 6:  I should NOT have written that the Cu ions cannot pass through the dialysis tubing….
    
     question 7:  What ions flowing can pass through the Dialysis Tubing (cellulose).
 
    question 8:  What is fizzing – I will get to this the next lab period.
    
–Error Analysis for the conclusion:
 
Chemical reactions that may have contributed:
 
                                              Mg    +   HOH (water)   —–>  Mg+2  + 2OH–   +   H2 (g)

 

Would these ions (Mg+2  + 2OH–) form a precipitate with ions already present?  The color of the entire battery was bluish?                                                                             What does that say about movement of Cu+2 ions? 

 

What factors were competing?  Based on the experimental voltage which factor dominated?
 

My video below illustrates the reaction occurring above (the fizzing or production of hydrogen gas).

 

______________________________________________________

9/9 – Friday Homework: –  

1.  Please complete Intro Voltaic Cells Worksheet 1 
      BUT PLEASE Complete QUESTION 1.
      THIS IS THE SIDE THAT HAS the TITLE. (OPPOSITE OF LAST NIGHT’s HW).
      Sorry both sides are numbered 1!
h
Intro Voltaic Cells worksheet 2 – skills.pdf
View Download

 

2.  Review question 2 with the key below.
 
Intro Voltaic Cells worksheet 2 – skills Key p.pdf
View Download
 
3.  And/or you can follow along with me going over Question 2 with lecture below.
Intro Voltaic Cells worksheet 2 – skills.pdf  worksheet Lecture:
j 
4.  Complete Question 1 and 2 (AP Question 2002 and 2003)  
      Intro Voltaic Cells worksheet 1.pdf worksheet – 
      ( They are Past AP problems ) –
 
Intro Voltaic Cells worksheet 1.pdf
View Download
Intro Voltaic Cells Worksheet 1 key pp.pdf
View Download
5.  Review with key posted above or the video posted below.   
 
     

3: AP Chemistry Voltaic Cell Concepts Review worksheet 2 Video:

      Start from the beginning in the video.

 

 

5: Intro Voltaic cell worksheet 1 video:

    

End of week 2!