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  Q1 : Week 7  – 10/16 – 10/20

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If you have not already please join the REMIND for this class. 

Please Make sure Your read all instructions for all assignments.    

LAB 3 – Electrolysis of copper (II) Chloride is  Late!

  ______________________________________________________                                                   Jump to:  Monday Homework         10/16 – Monday – A Day – 2/3a Lab, 4   

Main focus – 
 
      a) Test 2 – Voltaic/Electrolytic Cells/Cubic cell calculations/alloys – Review
     

      b) To Continue with particle and mole theory – 3b/4

Period 2 ,4 – 

           a) Test 1 – makeup  – Review with key.   

1st Test:                                    2nd Test:

mean = 80.25              mean = 85.8

sd = 12.1                      sd = 13.

 

           b) mole concept and particle theory theory in class  – 

Using the presentation we moved to Guy – Lussac’s work in period 2/3a                                                      Using the presentation we moved to Antoine Lavoisier in period 4                                                                                                                                                                                                             

Modern Atomic Theory – John Dalton! 

–  John Dalton                                                                                                                                                                                                           – Gay – Lussac                                                                                                                                                                                                            – Amadeo Avogadro

—————1800————————1803—————————————––1831———————————-—--1860———–———–1905

                Voltaic Pile                    Humphrey Davis                        Michael Faraday’s                                       Mole Concept         Atoms                     created!                   electrolysis of water               Laws of electrolysis                                               created.                 finally

                                                                                                                                                                                                                  accepted!

Period 3a – 

 1. Lab 4 complete 

   

Particle / Mole Theory Presentation:

_______________________ 
Lab 4 – The Metal Foil Lab

Objectives:

1. Calculate the Thickness of an aluminum and copper foil (thin piece of metal).

2.  Determine the number of atoms high a copper foil and aluminum foil are using volume, density and unit cell calculations.

The metal foil lab activity is not a formal writeup but please complete it as per the procedure in the handout that I gave.  A piece of paper with your work neatly written with units and sig figs showing all calculations will suffice.

Discussed the volume unit relatives cm3 = ml and the conversions of m3 to cm3metric prefixes:   

K H D [   ] d c m  —–>  micro, nano, pico

Conversion large number = small unit —–> small number = large unit
 
Lab 4- thickness of foils – 2017.pdf
View Download
  

Thin Foil Lab Instructions:

_____________________________________________________                                                                                                             jump to:  top  10/16 – Monday’s Homework: – 

1. Please view last night’s lecture again BUT start at 27:29 by clicking the video below. It will automatically start at 27:29. It will review the Law of Combining Volumes (by Gay- Lussac).   Please view this until to 34:20.

2. Please use the Law of Combining volumes tutorial below to complete the worksheet below.  You could just complete the worksheet and view with key, if you get the concept.

Law of Combining Volumes Diagrams.pdf
View Download
 
Law of Combining Volumes Diagrams key new.pdf
View Download

  

                                                                                                       

 

1 : Mole and Particle Concept Lecture : It will start at 27:29 when you start this. 

2: Law of Combining Volumed Tutorial : 

________________________________________________________________________                              Jump to:  Tuesday Homework / top    10/17 – Tuesday – B Day – 2, 3b/4 Lab                                           

Main focus – 
   
a)  To complete the Particle /Mole Concept History Lesson – to actually seeing atoms!!!
 
                                    Dalton –> Gay Lussac –>Amedeo Avogadro (Canazarro) 
 
b)  To write particle diagrams using Avogadro’s Hypothesis and Guy – Lussac.

c)  To Complete Lab 4  – mole and unit cell calculations – conclusion questions         

Period 2:

           1.  Guy – Lussac —> mole concept/particle concept—> smallest movie   

Period 3b:                                                                                                                                                                                                                                                                                                                                                                   1.   Antoine Lavoisier —–>  mole concept/particle concept—> smallest movie    

–Seeing atoms – Scanning Tunneling Electron Microscopy – (pizo electric crystal)

The need for a particle theory and mole theory.  They are deeply intertwined.
   

Richard Feynman said in Volume One of his Lectures on Physics:

If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generation of creatures, what statement would contain the most information in the fewest words? I believe it is the atomic hypothesis that all things are made of atoms — little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another.

Modern Atomic Theory – John Dalton! 

–  John Dalton                                                                                                                                                                                                           – Gay – Lussac                                                                                                                                                                                                            – Amadeo Avogadro

—————1800————————1803—————————————––1831———————————-—--1860———–———–1905

                Voltaic Pile                    Humphrey Davis                        Michael Faraday’s                                       Mole Concept         Atoms                     created!                   electrolysis of water               Laws of electrolysis                                               created.                 finally

                                                                                                                                                                                                                  accepted!

Period 4 –  Lab 4 complete 

                                                                                                                  

Particle / Mole Theory Presentation:

_____________________________________________________                                                                               jump to:  top               10/17 – Tuesday’s Homework: –

 

*Please read the following below before you begin your homework.

*We will complete next group of historical labs based on what was done as soon as the SOLVAY conference ended.  Chemical formulas will be built based on the percentages of mass determined experimentally.

In out Lab 5 we will determine the percent by mass of compound (hydrate) experimentally. SINCE compounds have fixed ratios or chemical formulas, this is a value that can help a chemist analyze and identify it.

In Lab 6 we will build a chemical formula of the hydrate by using the percentages of each part of the compound that we separate.Using the mole concept we will create a how many ratio (chemical formula)!!!

The homework tonight will based on starting with % by masses to determine the chemical formula (fixed ratio of how many atoms).  We will perform these type of experiments that was done after the Solvay conference, which was first step to determining the chemical formulas.

This is the beginning of Analytical Chemistry.

Law of Definite Proportions = the same compound will always have the same percentage of different elements in it. This really meant that the same compounds have the same chemical formulas!! 

 
And the different compounds have different chemical formulas MEANING different ratios of atoms CREATE the different compounds!!!

 

So the Law of Definite Proportions was a HUGE leap forward in Particle Theory! Thank you Joseph Proust!
 
1. Watch lecture 0 below. In the lecture I am modeling how to complete question 1 on the first side of the  Analytical Chemistry I – determining chemical formulas.pdf worksheet and then you will complete question 2 on the first side on your own. (We are using percent by mass to BUILD chemical formulas!!!).                                                                                                                                        When we use the mole concept!
 
Analytical Chemistry I – determining chemical formulas.pdf
View Download
 
2.  Please answer question 2 on the first side of the worksheet and review with key that is posted below.
 
Analytical Chemistry I KEY- determining chemical formulas.pdf
View Download  

1: AP Lecture : Calculating chemical formulas from percent by masses (that are obtained through labs). 

End of Thursday!.

______________________________________________________________________________             Jump to:  Wednesday Homework / top 10/18 – Wednesday – A Day – 2/3a Lab, 4                                 

Main focus –             
 
1. To Take the PSAT for 1oth graders.
2. To complete the Metal Foils lab
 
Period 2,3a:
 
1.  No class -PSAT 😢! I do not get to talk about mole/particle concept today?? 😭!
      Check the homework below.. Please stop by for a Hard copy of the homework sheet,
 
Period 4:
 No sophomores!😢
 
1.  Percent by mass —-> Hydrates mini lecture (Juniors will miss this tomorrow in class)
2. Lab 4 – Metal Foils lab complete / start homework.
  
                                                                                                                               

Particle / Mole Theory Presentation:

_________________________________________________________                                                                          jump to:  top                                     10/18 – Wednesday Homework: –

 
1.  Please view the last 17 minutes of the Greeks to Proust – percent error lecture below.  What I am doing here is transitioning from Joseph Proust (Law of Definite Proportions developed from percent by mass expriments) to discuss Hydrates.  These are salts (Ionic compounds) that have water inside the crystal of ions in an exact ratio.  We will work with with Hydrates in our next 2 labs.
 
2. Please complete the empirical&molec ditto hydrate combination.pdf worksheet and Review with key. 
       This worksheet used the basic skills that you used for side one of the worksheet from Tuesday night and then applies       it to a hydrate.  * If you need, I have posted a video below that review these problems if you need more help.
                                                                                                                                                                                                                             
empiri&molec ditto hydrate combination.pdf
View Download                                                   
                                                                                       
empiri&molec ditto hydrate combination KEY p.pdf
View Download
                            

1 : Greeks to Proust – Percent Error Lecture : It will start at the halfway point! 

2: Video Review of the Empir&Molec worksheet  : Calculating chemical formulas (empirical and molecular formulas) from percent mass data with Hydrates!

 

 ___________________________________________________________                      Jump to:  Thursday Homework /top  10/19 – Thursday – B Day – 2, 3b/4 Lab                             

Main focus –                                                                                                                                                         
a)  To Complete the Mole concept in class – period 2

b)  Analytical Chemistry begins with determining percent by mass (Hydrate lab) –

Our  homework has been based on starting with % by masses to determine the chemical formula (fixed ratio of how many atoms) or we had to get the % by mass through combustion analysis.  We will perform the type of experiment that was done after the Solvay conference which was first step to determining the chemical formulas.

Period 2,3b:

a)  Begin Lab 5 – Percent by mass of a Hydrate – Objectives and heating.

b)  Complete the Mole Concept in class during the heating.
         – Scanning Tunneling Microscopy
          – pizo electric crystals 
c)  Hydate background – more crystal lattice formations!
 
d) Make final mass measurements. 

Period 4:

e) Calculate the percent by mass of water in the copper (II) pentahydrate 

f)  Complete Lab and hand in

   

Richard Feynman said in Volume One of his Lectures on Physics:

If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generation of creatures, what statement would contain the most information in the fewest words? I believe it is the atomic hypothesis that all things are made of atoms — little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another.

                                                                                                                                                                                                                                                                                                                                                                 

                                                                                                    

_______________________________________________________________________                                                                                                                                  Lab 5 – Percent mass of water in a Hydrate

LAB 5 – copper sulfate pentahydrate lab.pdf
View Download

Let’s look at an ionic crystal that has no water called anhydrate.  
 
Lets look at copper (II) sulphate : CuSO4  :

 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.
The sticks represent the bonds or the attractions between the ions.

Its hard but if look inside the crystal there is one Cu per sulfate ion.
 
Lets look at the formula of the hydrate of the same salt : copper (II) sulphate pentahydrate: 
 
 CuSO4 ● 5H2O

Notice the Dot between anhydrate and water.  This Dot means “WITH” and not to multiply.   

There are exactly 5 water molecules for every 1 Cu+2 and  1 SO4-2 in the crystal.
 
Lets look at the crystal formation of copper (II) sulphate pentahydrate: 

 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.  This is a fixed ratio (stoichiometric ratio).

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.
                                                 CuSO4 • 5H20   ——->    CuSO4  (s)     +      5H20  (g)                                                                                                                               Heat                                         
                                                                                                                                                                                                                 Today we will be able to do the following:           
         a) Determine. the mass of your annhydrate (dried hydrate)
       b) Determine the mass of the water (THAT was in your crystal)
       c)  calculate the experimental percent by mass of water:
 
            % by mass =  Mass of the part (mass of water missing)         x     100  
                                    Mass of the whole (mass of original hydrate)
 
         d)  calculate the Theoretical percent by mass of water using the chemical formula of the hydrate:
                 
                                                                                    CuSO4 • 5H20
 
                    Given the formula above, determine the percent by mass of water of the hydrate:
 
                                           Assume you have 1 mole of CuSO4 • 5H20:
 
                                Thus in 1 mole of the hydrate you have 5 moles of water:
 
                                For every one (CuSO4 • 5H20) you have 5 moles of water.
 
                                                                         1               :               5
                                               
                                    Ratios of how many!!! This is why we need a mole theory!                    
 
                               
                          % by mass =  Mass of the part (mass of 5 moles of water)         x     100  
                                                   Mass of the whole (mass of 1 mole of hydrate)
 
*Mass of 1 mole of any compound (with a unique chemical formula) is the sum of the atomic masses of all atoms in the formula or molecule. You need the periodic table!
 

Percent by Mass of Water in a Hydrate Lab: 

______________________________________________________                                                                        jump to:  top                             10/19 – Thursday Homework: – 

 
DUE Monday, 10/23:
 
1. Please complete the Lab 4 using the video of the instructions below.  If you still need to measure a mass or dimension of Al or Cu please use the 2nd Video to obtain those.

 

DUE Tomorrow:

2.  Please watch lecture 0a, which is posted below with Thursday nights worksheet (side 2 – questions 3 of Analytical Chemistry I – determining chemical formulas.pdf. This the other side of the worksheet that we worked on Thursday night.  We will do question 3 together before you do question 4 on your own.  Tonight we will use analytical chemistry (discovering formulas using particle and mole theory in Combustion Analysis.)  Please read these notes before you begin.

– Combustion (burning):  
A redox reaction (imagine that) that uses O2 as the oxidizing agent on a fuel (normally a hydrocarbon)
 
                                             C?H?   +    O2    →   CO2     +     H2O
 
                                                      Notice that combustion is a redox reaction.
 
Using the law of conservation of mass by Lavoisier and the idea that every unique compound has a unique formula (law of definite proportions by Proust) we can determine the chemical formula of hydrocarbon fuel if we have the mass of the CO2 and  H2O that is produced.
 
The key to solving these problems are percent by mass!
 
Analytical Chemistry I – determining chemical formulas.pdf
View Download  
 
3.  Please answer question 4 of the same worksheet and review with key that is posted below.
 
Analytical Chemistry I KEY- determining chemical formulas.pdf
View Download
 
              

1: Thin Foil Lab Instructions : 

 

1: Thin Foil Lab measurement : If you still to measure the mass or dimensions of Al or Cu please use this video to grab those measurements

 

2: AP Lecture 0a : Calculating chemical formulas from Combustion analysis (that are obtained through labs). 

 

 .______________________________________________________________________                Jump to:  Friday Homework/top   10/20 – Friday – A Day – 2/3a Lab, 4                                   

Main focus –

a) To perform Lab 5 and Lab 6 in determining the percent by mass or the empirical formula (in hydrates).

b) To complete the error analysis of the hydrate labs

c) Complete Mole / Particular concept presentation

Period 2:

1. Begin the heating of the unknown hydrate for Lab 6

2. Complete the Final Calculations of Lab 5 – percent by mass of water

3. Complete the conclusion questions for Lab 5, write conclusion and hand in. 

Period 3a:

4. Final heatings, complete calculations of Lab 6 and hand in.  
 
5. Complete mole concept presentation/molecular vs empirical

 

Period 4:

1. Begin the heating of the unknown hydrate for Lab 6

2. Complete mole concept presentation. 

3. Final heatings, complete calculations of Lab 6 and hand in.    

Particle / Mole Theory Presentation:

 

___________________________________________________________________________________ 
Lab 6 – Determination of the Empirical formula of a Hydrate

                    *Determine the chemical formula of a hydrate:  

LAB 6 – Empirical Formula analysis of Hydrate.pdf

 
We will determine the formula of the hydrate in this lab much like your homework this weekend. Imagine that the work in the class parallels what we do in Lab!  To complete the chemical formula we need to obtain the grams of water lost and the grams of anhydrate remaining from drying out another hydrate.
The grams (how heavy) of water and the anhydrate will be determined the same way as Lab 5.  But we will take these grams (how heavy) and convert it to a how many number (mole concept) to get the ratio of water to anhydrate.
 

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! 
 

The Empirical Formula of a Hydrate: 

___________________________________________________                                                                         jump to:  top                                10/20 – Friday’s Homework: –

1.  Precipitation Analysis:   Now that we can determine chemical formulas from heating (Lab 6) 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 (USING RATIOS OF MOLES!!!!)
 
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 stoichiometry.
 
b) Watch Lecture 1.2 and follow along with me to complete questions 4, and 5 as we use precipitation 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!
                                                                                                                                                                                                                            Analytical Chemistry II – Mol,Dilution, precipitation analysis.pdf
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Analytical Chemistry II KEY NEW – Mol,Dilution, precipitation analysis.pdf
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a) Lecture 1.1 : Molarity of ions

b) Lecture 1.2 : Preciptation analysis

End of week 7!