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Archive – Q3 week 5 – 19-20

Week of  3/2 – 3/6 –   PLEASE REFRESH!

3/2 – Monday – period 2/3 
 
1.  Review Backside of IMF Comparison worksheet 1.
 
2. Review IMF Comparison worksheet 2.
 
IMF comparison 2 worksheet Key.pdf
View Download
3.  Ideal vs Real solutions.
 
Review the concept of solubility/miscibility with water
 
                                                    – Like dissolves Like really means?? 
 
Mini – lesson on Ideal solutions- 
       Stronger IMF’s                                                                                                                              Weaker IMF’s
 Lower Vapor Pressure                                                                                                          Higher Vapor Pressure
   Lower Boiling Point                                                                                                                Higher Boiling Point
 
Today’s Demo:
 
 
4: Bonding TEST 3 – MO diagrams, Band theory, crystal field splitting, chromophores, intermolecular attractions, types of compounds.
 
                             period 4 –
1: Bonding TEST 3 – MO diagrams, Band theory, crystal field splitting, chromophores, intermolecular attractions, types of compounds.
 
3/2 – Monday Homework: 
1. Today’s Test will be available by 8th period.  If you do not pick it up I will scan and email it to you  this afternoon.  Please study for the bonding test 4 MO/GAP/ IMF test – using the video below  
which will be unlocked later today.
 
 It is time to eliminate repeated mistakes on the same concepts. Pay attention to how I reviewed to explain solubilities and boiling points! I will grade that section a bit tougher on Tuesdays test. Remember that it will be the best grade out of 2 tests.
 
*Also the key will be posted in PowerSchool.
Bonding test 3 – MO/band/IMF Class Review:
3.  Have a French sandwich with French bread and dressing.
 
End of Monday..

3/3 – Tuesday – period 2 – 
 
1. Bonding test 4 – 
                               period 3/4-
 
1.  Graphite flaming pencil demo – 
 
2. Bonding test 4 – 
 
3. Handback Periodicity /Bonding Tests – Review
 
3/3 – Tuesday Homework:
 
1.  TLC (Thin Layer Chromatography) Lab background and Hypothesis writing.
 
READ BELOW!!!!
 
This is our last formal lab this year.  I would like for you to write a background on how TLC works and relative strength of the different IMF’s in the molecular compounds (chemical indicators) that make up a industry standard mixture called Universal Indicator.
 
Universal Indicator Acid/Base Indicator that has a unique color for each pH value:
 
 

A lot of pool kits that measure pH use Universal Indicator!
Universal Indicator can accomplish this broad range of colors because it is a homogeneous solution of three Acid/base indicators (CHROMOPHORES!!!!!!!!!!!!) that change their amount of conjugation based on the concentration of available protons (H+) or hydroxides (OH).
 
Also do not forget the acid/base indicators ARE CONJUGATE ACID and CONJUGATE BASE solutions which are Buffer solutions.
 
                                              HIn                             —->                            H+       +         In
 
                                         Conjugate Acid                                                                                      Conjugate Base
                                              one color                                                                                                 New color
 
  Phenolphthalein is an example:
There are slightly different types of Universal Indicators that use slightly different mixtures of indicators. We will using the BOGEN Universal Indicator mixture.
 
Bogen Universal Indicator Mixture:             1.   Methyl Red                      pKa = 4.95
                                                                                         2.  Bromothymol Blue         pKa = 7.1
                                                                                         3.  Phenolphthalein             pKa = 9.4
 
So the colors of each pH from above are due to the mixture colors of each indicator at a certain pH levels:
                                                                                                 (negative theory of light)
 
Okay so the point of this lab it separate each of these 3 individual molecular substances by using TLC (Thin Layer Chromatography).  Thin Layer Chromatography is another physical way we can separate mixtures. 
 
– We have separated homogenous mixtures before using evaporation in the carbonate lab where we added HCl to an unknown white powder (that was either NaHCO3 or Na2CO3) and created NaCl (aq) and CO2 that left as bubbles.  We boiled off the water (separated the H-Bonds of water) and obtained dry NaCl (s) which we used by stiochiometry to determine our unknown. Connections!!!!
 
– we also studied distillation (of Coca-Cola) as another physical separation technique of mixtures!
 
– we also used filtration of a precipitate to separate a mixture in our gravimetric titrations!
 
Remember that solutions are mixtures that are soluble that are held together by IMF’s!  When we separate a mixture it is a physical change because we are not breaking bonds we are ONLY BREAKING IMF’s between MOLECULES!!!
 
TLC just like all chromatography separates a mixtures based on the idea that in a mixture the individual molecules retain thier individual properties since their chemical formulas are not changing in the process.  This means that each chemical indicator will retain their individual solubilities (their percentage of non-polarity due to the amount of predominant LDF forces or their percentage of polar nature due to the amount of dipolar and H-boding) in the mixture. 
 
Thus in TLC we will separate the 3 acid/base indicators by their solubility to either a mostly non- polar solvent (mobile phase – hexanes) or polar solvent (stationary phase – Silica Gel).  
 
We will spot a TLC plate with Universal Indicator in a starting position close to the bottom of a Silica TLC plate (stationary polar phase) and add a liquid solvent – hexanes (non-polar mobil phase) that move up the Silica TLC plate by capillary action.  When the solvent reaches the “spot” or mixture EACH component of the mixture, 
Methyl RedBromothymol Blue, and Phenolphthalein will have a choice to either stay with the polar Silica Gel on the TLC plate or move with the non-polar mobil hexanes.  BASED on their individual molecular structures (that define the IMF’s that they have), each chemical indicator will have a unique amount of polar or non-polar characteristics AND they will each move a unique distance up the TLC plate.
 
– If one of the chemicals is more polar (have stronger dipolar forces or have H-bonding) than the other three than they will prefer the Silica TLC plate and MOVE LESS than the other chemical indicators of the mixture that must have more non-polar characteristics.  
 
– The chemical indicator that is the most non-polar (have mostly LDF’s with less dipolar forces), would prefer to be attracted to the mobile non-polar hexane solvent and thus move up the plate more.
 
*Remember this a separatory technique based on solubility. Solubility is based on how similar the IMF’s have with the mobile non-polar solvent (hexane) or the polar stationary solvent (TLC silica Plate). Look at the two solvent molecular structure above to identify what IMF are most similar with each solvent! 
 
The distance that the individual chemical indicators move compared to the original spot will be measured.  
 
Tonight you will accomplish 2 things:
 
1.  Write a background on the TLC of Universal Indicator Lab.  
        This will be our last formal lab write – up.  You will have an email with the link to your shared doc to begin this lab.  The focus of your background MUST include a comparison of the polarity and non-polarity of the three chemical indicators in Universal Indicator.  This comparison must include a discussion of the IMF’s of the three chemicals using diagrams of their molecular structures.  Thus your background must include molecular structure that you should search for and place in your background. The whole purpose of the background is to develop a your argument or your position on whether which chemical indicator is the most polar and non-polar. 
 
2.  Write a Hypothesis based on your position established in your background.
        Basic Format: If the independent variable does this the dependent variable will do that .
 
           The Dependent Variable is the distance the indicator moves up the TLC plate.
 
                            We will measure that distance by a calculation called Rate of Flow = Rf
 
For those that had me last year in AP Biology we separated the different pigments in the photosystems in the chloroplasts in spinach leaves.  We were able to separate three different pigments (CHROMOPHORES!!!!!!!)  in that lab.
 
Yellow layer – Carotenoids – 
 
 
Green layers – Chlorophyll A and Chlorophyll B – is one slightly more polar?
 
– Notice these pigments are chromophores!!!
 
– There were three layers separated in the Time Lapse Chromatography below.  Looking at the pigments separate in the video below, and the molecular structure above can you identify the chemicals in the chromatograph? Why was the yellow layer almost at the top while the 2 green layers barely moved at all?
– Also notice that we did not spot this TLC plate, we rolled a coin on a spinach leaf unto the TLC plate to make line. The green line was our starting point.
End of Tuesday..

3/4 – Wednesday – period 2/3 – 
– period 2/3- 
 
– phase diagram of water and carbon dioxide:
 
1. Discussion of universal indicator, ph, Chromatography, AP Biology pigment lab
 
– making of dry – Ice – deposition – JOULE-THompson effect – IMF’s!!!!!
 
2: CO2 Demo – Universal solution and dry ice:
        warm water and Universal (green) plus few drops of .1 M NaOH solution- add solid CO2
        on overhead projector with light hole (from sunset demo)
 
3. TLC (Chromatography) of Universal Indicator Lab
 
TLC of Universal Indicator p.pdf
View Download
 
 
– period 4
 
1. Discussion of universal indicator, ph, Chromatography
2. TLC (Chromatography) of Universal Indicator Lab- data collection
    
 TLC of Universal Indicator p.pdf
                              
 
Presentation used for discussion:

3/4 – Wednesday – Homework – 

 
TLC Lab write- up – Data gathering and calualtions
 
1.  Please download Logger Pro from SELF – SERVICE when you are still in school.
 
2.  Make sure everyone has the picture of the chromatograph that I sprayed with a base to expose          the phenolphthalein spot.
 
From a lab group today:
 

 

*Notice that the phenolphthalein trails the methyl red.  It is probably faint in your picture but it is there.
They do not use a lot of it in the Bogen Universal indicator mixture and thus it is not a concentrated spot.
 
Our next step is to calculate the RATE of Flow for each SPOT .
 
RATE of Flow = R = distance each spot traveled from the starting position (bottom line)
                                                                  distance to solvent font (see diagram)
 
WE Need to measure these spots and we will do so WITH the pictures of your labs chromatograph and LOGGER PRO.
 
1. Make sure you have downloaded Logger Pro in school today.
2. Open Logger pro.
3. Click on Insert, Picture, Picture with photo analysis
 
4. Find your picture of your chromatograph in your computer and click open.
 
5. Your picture will appear. If it is too big or small just click the upper right corner of the image to resize so that you can see the entire image.
6.  Click on the set scale button on the right of the image.  The 4th button down. The one that is darkened.
7. When you click the set the scale button a cross appears. Please click and drag with that cross from the top of your chromatograph to the bottom. WE are setting the computer scale so that it will be able to measure.  Everyones TLC plate is 75 millimeters (mm) as I illustrated in the diagram above. Once you drop and drag the cross the exact length of the TLC plate ADD 75 for the distance and mm for the unit in the pop-up box.
Then click Ok to close the pop-up box.
 

   

8. Now we are ready for the computer to measure for us.  Please click on the 5th button down, the photo distance button and the cross appears.  Click and drag with the cross from the starting position to the middle of one of your dots.  I did the methyl red of the last group. The program will give you a value in mm for that distance. Make sure that you click and drag with the cross from exactly from the starting point to the middle of the dots. Record each distance and measure all of your spots this way.
-Also measure the Distance to the solvent front – Thank You Rose H.
 
9. Calculate the Rate of Flow for all 9 dots. Use page three of your handout portion of your lab to organize you data.  Please average your Rate of flow for each indicator in the mixture.
 
*Also identify each spot from your image of the chromatograph as I did in the illustration above.
 
10. Place data tables, images, into your Data section of your lab.
 
11.  Complete your Procedure, Data, and Results section in the shared doc that I sent you yesterday.
 
 End of Wednesday..

3/5 – Thursday  – period 2 – 

 
1. Discussion of Lab Write-up and conclusion
 
2. Use acid base indicator presentation to review components of the Lab
 
        1. discussion of how acetone can “dissolve” styrofoam.
           – reason why ethyl acetate can be dissolved in hexanes
 
        2.  Capillary action / surface tension explained
 
        3. rate of flow depends on solvent
 
3.  Thermodynamics intro a little..      
                                    period 3/ 4 – 
 
– phase diagram of water and carbon dioxide:
 
1. Discussion of universal indicator, ph, Chromatography, AP Biology pigment lab
 
– making of dry – Ice – deposition – JOULE-THompson effect – IMF’s!!!!!
2: CO2 Demo – Universal solution and dry ice:
        warm water and Universal (green) plus few drops of .1 M NaOH solution- add solid CO2
        on overhead projector with light hole (from sunset demo)
3. Discussion of Lab Write-up and conclusion
 
4. Use acid base indicator presentation to review components of the Lab
 
        1. discussion of how acetone can “dissolve” styrofoam.
           – reason why ethyl acetate can be dissolved in hexanes
 
        2.  Capillary action / surface tension explained
 
        3. rate of flow depends on solvent
 
 
Time Lapse – of TLC of Universal Indicator:
 
 
 3/5 Thursday’s  Homework:  
 
1:  Work on the TLC of Universal Indicator Lab.  Lab is due next Monday, March 9th.
       – you need to add the following components:
 
        Conclusion – discussion that uses data to determine the relative polarity of each chemical indicator that is in the mixture called Universal Indicator.  Using diagrams of the molecular structure determine what part of the structure may have been responsible for the outcome on the chromatograph.  Make sure you are discussing the IMF throughout and solubility. Tie in your background to help with this discussion. This is a very descriptive lab.
 
 
2:  Please view slides 1 – 15 of the Thermodynamics presentation AND fill in the notes that is missing in the note packet that I gave.
 
3:   Review your NOTES and complete the Form Below.
Thermodynamics Form 1:
 

Thermodynamics Form 1 19/20

 

 
End of Thursday…

 3/6 –  Friday – period 2/3 – 

1.  Review of Thermo form 1 – 
     – discussion of state functions, path functions, delta E
 
Thermodynamics Form 1 1920 – Form Key p.pdf
View Download
 
2: Thermodynamics to calorimetry- follow along note taking
 
THermo read along – Thermo notes.pdf
View Download
 
                                period 4 – 
1.  Review of Thermo form 1 – with printed key 
     – discussion of state functions, path functions, delta E
 
Thermodynamics Form 1 1920 – Form Key p.pdf
View Download
 
2: Thermodynamics to calorimetry- follow along note taking
 
Thermo 1 calorimetry.pdf
View Download
 
thermo 1 calorimetry key 0809.pdf
View Download
Fire syringe demo: (work done a system = +W = increase in internal Energy)
 

 

                                    
3/6 Friday Homework: 
1:  Complete the TLC of Universal Indicator Lab – due Monday (3/9)
1:  Please watch lecture and follow along with me with the THermo read along – Thermo notes.pdf worksheet that we started in class.
 
2: Complete questions  1 – 3 in the thermo 1 calorimetry.pdf  worksheet and review with the key.
     I completely review these questions with you in the lecture below.
 
Thermo 1 calorimetry.pdf
View Download
 
thermo 1 calorimetry key 0809.pdf
View Download
 
Today’s Homework lecture:  
 
3.  Complete the following worksheet based on calorimetry from constant pressure calorimetry with no chemical change.
Calorie problems .pdf
View Download
 
Calorie problems key complete p.pdf
View Download
 
4. Complete the form:

 

Calorimetry Practice Form ‎(MC)‎

 
 
End of week 5!!!

 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
THIS IS NOT PART OF YOUR WEEK..
For transistors lesson:

MO Conjugated Theory

 
video 1:

 

video 2:

 

video 3:
 How a quantum computer work?
  This is not part of the assignment.
Vacuum tubes videos
 
 
 

 
Notes for next week.  Review Enthalpy of dissolution after Hess law.