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## Q2 : Week 10 – 1/22 – 1/26

<- Week 9

#### Refresh this page every time you arrive!  I update this daily!!!

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

– Regarding Homework assignments – IF you cannot complete the assigned homework before school the next day you must email me.

The Tum’s lab is Late. The aspirin lab is due!.

Lab 17, 18, 19, 20 ARE DUE!

Lab 16 –> I will help finish this week!

_____________________________________________________                           Jump toMonday Homework / top      1/22 – Monday A Day 2, 3a Lab/4

Main focus –

a) To review the gas law unit with review of the calculations of the Lab 20.

b) To observe real gas behavior through condensation of water vapor and oxygen.

Period 2/3a: –

1: Review Lab 20 calculations – hand in.

2.  raquetball/Gold fish/ Liquid oxygen demo

–  N2 (l) – boiling point  =  -196 degrees Celsius or 77 Kelvins.

–  O2 (l) – boiling point =  -183 degrees Celsius or 90 Kelvins.

– Clearly the boiling point or the condensation point of oxygen (-183 ° C)  is above the boiling point of nitrogen (-196 ° C). This means that liquid nitrogen is cold enough to condense oxygen to a liquid. If gases condense then they Have REAL significant Intermolecular Attractions.

Period 4: –

1. Lab 20 data collections.

2. Lab 20 calculations.

3.  raquetball/Gold Fish/ liquid oxygen demo – Real

– shrink wrap

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Lab 20 – The Molar Volume of Hydrogen

Lab 20 – Molar Volume of Hydrogen .pdf

Vapor Pressure of Water table.pdf

Here is the unbalanced chemical reaction (single replacement reaction).

Mg (s)   +    HCl (g)   —>   MgCl2 (aq)    +  H2(g)

Dilute Excess HCl will be added to a Eudiometer tube with a small mass of Magnesium secured by a copper wire.  Only the the Mg will react as only the Mg reacts spontaneous with protons from the HCl OR the proton is a strong enough oxidation agent that can transfer electrons from the metal.  The copper will not react as per the Standard Reaction Potential values posted below:

Cu+2   +     2e-    –>  Cu (s)        0.34 v
2H+     +     2e-    –>  H2 (g)        0.00 v
Mg+2   +    2e-    –>  Mg (s)       -2.37 v

The copper will that will affix the magnesium will not react in the acid and thus all the hydrogen produced will be produced by the oxidation of the Mg metal.

Molar Volume of Hydrogen Calculations:

Liquid Nitrogen and the gold Fish –

Liquid Oxygen Demonstration –

liquid oxygen – Rate of reaction

1. Please complete page 3 and page 7 of the Gas Law Test. It was given out in class.

2.  Study for the in class portion tomorrow. A great worksheet to review would be the following.

Daltons Law Worksheet 2.pdf

Daltons Law Worksheet 2 Key.pdf

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______________________________________________________________________                                     Jump to: Tuesday Homework / top  1/23 – Tuesday –  B Day – 2, 3b/4 Lab

Main focus –

a) To take the Gas Law TesT!

Period 2:

1Gas Law Test

2. Real Gas Demo : Liquid oxygen

Period 3b/4:

1. Gas law test

2. Complete Lab 20 –> Final calculation of percent yield for volume of hydrogen collected.

1. Please complete Page 4 of the Gas Law Test. You should of pulled it out of your folder of fun today.  That page is due tomorrow morning,

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____________________________________________________________________________                       Jump to: Wednesday Homework / top  1/24 – Wednesday – A Day 2, 3a Lab/4

Main focus –

a) To complete the Gas Law Test

Period 2/3a: –

1.  Complete Gas Law Test

Period 4 –

1.  Complete Gas Law Test

Real gas Demos: Liquid oxygen, Goldfish, raquetball

– shrinkwrap

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Connections and Transition:

We have for the last 5 months have been on tour through many topics of chemistry (redox, solution, acid/base, etc.) using the mole concept to perform stoichiometry.  Stoichiometry requires a particle and mole concept to predict and calculate the values of our chemical reactions and of course to determine the chemical formulas of our chemicals themselves.  We have been using the macro approach to chemistry as we have been looking at groups (moles) of molecules and formulas (if salts) to using the ratios to answer so many chemical questions.  We have not considered the micro approach yet AND NOW we will.  We will now look at the structure of atoms.

Before we begin with Atomic Structure we need a segway!  The first day must connect to the last day!  The connection is very easy.  Historically we studied the development of the particle (atom) theory with the mole theory. Both of these ideas were necessary in order to do any stoichiometry.  REMEMBER that chemistry really only began in the Karlsruhe Congress in 1860 when Stanislao Cannizzaro championed Amedeo Avogadro’s notion that equal volumes of gas at the same pressure and temperature held equal numbers of molecules or atoms, and the notion that equal volumes of gas could be used to calculate atomic weights.

Chemistry began when we USED GASES that we cannot see to determine what the atoms or their arrangements looked like from  Gay- Lussac’ s  whole number volumes when he reacted gases with gases.

Using Avogadro’s hypothesis ( V = n * K) Cannizzaro was able to for the first time show that stoichiometry can be done for chemical reactions as the molecular formulas of chemicals could be determined!!!  He essentially was able to fill the boxes with what the arrangements of atoms MUST be IF YOU ACCEPT 2 NOTIONS:

1. ATOMS are neither created nor destroyed BUT just rearranged!
(LAW of Conservation of Mass)

2.  Equal volumes of 2 (IDEAL GASES) MUST have the same number of molecules if they are
under  the same Temperature and Pressure (Avogadro’s Hypothesis!)

WE USED GASES TO DETERMINE ATOMS!

So it only makes sense that we now look more deeply at the particles we discovered through our understanding of gases!

So we begin Atomic structure.

2. Most important atomic structure experiments-

What is the Transition Here? How does atomic structure connect with gases???
Hmmm?? May be slides 21 – 42 will awaken your senses!!!

Everything we did in stoichiometry is due to atoms!!!!!

Please complete form with a specific description in your own words of the experiment from the following scientists using the resources below : (I need specifics and not simple generalizations).

a: J. J. Thompson  : Slide 45 – 53 on presentation below/ MIT Lecture 1 @ 30:40

b: Robert Millikan  : Slide 59 – 60 on presentation below

c: Earnest Rutherford:  Slide 67- 72 on presentation below/ MIT lecture 2 below

d: H. Moseley  : Slide 74 on the presentation below AND THE LINKS BELOW:

e: James Chadwick : Slide 74 on the presentation below

3. Complete a familiar form on atomic structure based on a Grodski (Sorry NOT MIT!) lecture and the information above.

Atomic Structure 1 Presentation (end of the particle theory presentation):

MIT Lecture 1: It starts right where you need to listen

MIT Lecture 2: It starts right at the beginning with Rutherford’s experiment.

2:  Atomic structure Form 1:

Grodski lecture 1 : It starts at beginning with the G(r)eeks!

3:  Atomic structure Form 2: 3 submissions can be used!

End of Wednesday!

________________________________________________________________________                            Jump to: Thursday Homework / top 1/25 – Thursday B Day – 2, 3b/4 Lab

Main focus –

a) To Review the experiments of JJ Thompson, R. Miliken, Earnest Rutherford

b) To Review the experiments of H.Moseley and Chadwick

Period 2:

1.  Hand back and Review Gas law Tests

2.  Atomic Structure Begins – “connections”

Period 2, 3b:

1.  Same as above.

1.  Hand back and Review Gas law Tests

2.  Atomic Structure Begins – “connections”

Atomic Structure 1 Presentation (end of the particle theory presentation):

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Cathode Ray Tubes NOTES :

Thomson presented three hypotheses about cathode rays based on his 1897 experiments:

1. Cathode rays are charged particles (which he called “corpuscles”).
2. These corpuscles are constituents of the atom.
3. These corpuscles are the only constituents of the atom.                                                                                                                                                                                                                                                      The third hypothesis was proven false by his student Earnest Rutherford ( the father of the atomic structure).

As a result of J.J Thompson’s experiments he developed a model of the atom, where electrons existed as very small negatively charges particles in a massless positive cloud. This was called the “Plum Pudding” or “Raison Cake” model.

electricalfundablog.com/

J.J. Thompson’s Experiment explained:

2.  The Mass Spectrometer Assignment Detecting Isotopes and determining                                                                                                                             average  isotopic mass.

a) Please listen to the video on the basics of mass spectrometry below:

Atomic Structure Isotopes Mass Spectrometer.pdf

Atomic Structure Isotopes Mass Spectrometer Key.pdf

d) Complete the Atomic Structure – Mass Spectroscopy .pdf worksheet and review with the key.

Atomic Structure – Mass Spectroscopy .pdf

Atomic Structure – Mass Spectroscopy Key.pdf

e) Complete the  form: Mass Spectrometer – Isotope Determination – 22-23

******Question 5 will reveal itself after or during Questions 6.

You will have a total of 1 submission to this form! I will return the grade to the form tomorrow morning.

Mass Spectrometer Form :  1 Submission only!!!!

End of Thursday!

_________________________________________________________________                                         Jump to: Friday Homework / top   1/26 – Friday – A Day 2, 3a Lab/4

Main focus –

a) To complete atomic structure experiments that lead to the Mass Spectrometer

b) To introduce the light as a wave and describe the crash course in particle and wave           theories.

Period 2/3a:

1. Complete the Atomic Experiments from Earnest Rutherford —-> Moseley —–> Chadwick

2.  Mass Spectrometer Review – (did not get to this below):

a) Isotopes, weighted average problem, atomic mass, most abundant naturally occurring isotope.

3.  Particle Theory on Direct Course to collide with or Light or wave theory!

Particle theory of the atom on a crash course with wave behavior of light
– Light as wave – double slit – Thomas Young
a) Laser pointer demo with double slit

b) Destructive interference, Constructive interference

c) IR remote –

4.  Ultraviolet Catastrophe!

#### Light and The Photoelectric Effect

Period 4:

Same as above –> Moseley —> Chadwick —> Mass Spectrometer

Atomic Structure 1 Presentation (end of the particle theory presentation):

Light into the Bohr Model:

liquid oxygen – Rate of reaction

Liquifying Oxygen (condensation of oxygen) by liquid Nitrogen.

YOU MAY MAKE ONE MORE SUBMISSION TO THE MASS SPECTROMETER FORM  from Thursday.

This weekend we will investigating another phenomena that could not be explained (like the Crook’s Tube) that wound up starting the Quantum revolution in physics!  At the time (1895 ) it was thought there was nothing more to discover in physics and BUT there was a REVOLUTION coming that will pit classical old world physical ideas against a NEW form that will challenge and rock the scientific community to its core.

The particle theory of the atom (electrons)  WAS ON A a crash course with the wave behavior of light.

It all begins with explanation of the ultraviolet catastrophe that began this Revolution.

1. Please view the lecture (Lecture 2.11) from 0:00 – 8:01 and complete ONLY question 1 with me on the worksheet.

atomic structure – 1 – photoelectric effect.pdf

atomic structure – 1 – photoelectric effect KEY.pdf

Grodski Lecture: (part of lecture) 0:00 – 8:01

2. Please view the Plank’s Constant and the Origin of Quantum  from 2:56 – 15:15.
PBS Digital Studios (part of video)  watch only 2:56 – 15:15

3. Please complete the Form below on the Ultraviolet catastrophe – You will be directed us the other resources below for a particular question in the form.

Figure 1:
Grodski Wave Demo:

Article for question 10:

From our reference tables:
NOTES On the Ultraviolet Catastrophe:
There is just not enough energy present at fixed temperatures to elicit high frequency radiation because the oscillators (electrons and atomic nuclei) are taking in the energy in constant chunks (photons) and re-emitting these photons. The energy is not a constant flow and does not build up.

The heater in the Black Body radiator makes the atoms vibrates at all different frequencies and thus a wide range of photons are released because temperature is proportional to molecular motion range.

The lower energy vibrations use up the energy first, leaving very few chunks or quanta to excite  the higher energy vibrations.  The higher energy vibrations (at the smallest wavelengths) are needed to elicit higher frequency radiation and there is just not enough of these photons available.

With classical physics, energy is a continuous stream of energy, and oscillators in the black bodies can vibrate with ANY frequency thus have an infinite amount possible frequencies or modes. Classical physics suggests that kinetic energy that is absorbed is absorbed evenly throughout every possible mode (or frequency ). This is called the Equal Partition Theorem and this theory work very well in many cases to predict kinetic energy in many systems.  It did NOT do very well in the explanation of wavelengths emitted from black bodies. Its formulas (of equal partition called the Rayleigh Law) led us with predictions that led to the “catastrophe” because energy that was absorbed by the black body was absorbed equally by all modes of vibration. Because there are more vibrational modes that are smaller (limit to zero) these high frequency modes would gain more of the energy than the less frequent lower frequency modes.

Max Plank’s new formula was able to predict the experimental results IF the frequency which is proportional to the Energy ONLY existed in discreet bundles and was not continuous! That is matter in the black bodies could not vibrate at any frequency and absorb ANY amount of energy. They could only absorb certain energy amounts AND only start vibrating or oscillating at certain frequencies!

Max Plank started the quantum revolution!

E (energy)  =     h          *         f
Energy  =  Planks   *    frequency
Constant

Planks Constant represents a proportionality constant (price per seat!) or the  smallest divisible value that frequency (can have).

It represents the “energy chunk” = 6.63 x 10-34 J s (Joule seconds)

Energy is absorbed in chunks of this small value x the frequency of the oscillator.

Energy is not continuous!

The oscillators of course are the atoms!!!

3: Ultraviolet Catastrophe Form:

End of Quarter 2!