Atom notes and Oleic Acid Lab

Walking into the classroom our hopes were high that the Homecoming Genie would finally make an appearance. But, with only a limited amount of people wearing the spirit day attire of a toga, he failed to reveal himself. After the Genie did not appear we moved on to go over the post lab of the Oleic Acid lab.

1. Finding the volume of oleic acid per drop of solution

Previously in this lab we were to find out the volume of a single drop of methanol. The lab gives you the information that the solution that was used contains .500% of oleic acid. You would then take the number you received from finding the drop of methanol and multiply that by .05.

2. Find the surface area of the oleic acid

The equation for finding the surface area of a circle is π*r². To find the radius you need to divide the average diameter you got earlier and divide that by 2. Then you plug the radius into the equation and you get the surface area.

3.Find the height of the oleic acid layer

The equation to find the height is: volume of oleic acid = surface area * height. You would plug in the volume of the oleic acid that u got in 1 and then the surface area you got from 2. Then divide the volume by the surface area to get the height of the oleic acid.

4. Calculate the width of the molecule

The lab gives you the information that the ratio of height to width for the oleic acid is 18:3. Using this you would take the ratio and turn it into an equation that looks like this:

18 = _h_

3 w

replace the h with the height you got from 3 and then cross multiply so you end up with: 18w=3(the height of the molecule). Then you solve the equation to get the width of the molecule.

5. Calculate the volume of one oleic acid molecule

The equation for the volume is:

V = (4/3) * π * r³

You then take the width of the molecule and divide that by 2 to get the radius. Plug the radius into the equation and solve the equation to find the volume.

These are just a few of the questions we went over in class and the harder ones of the post lab. When Mr.Lieberman finished answering questions we went on to review the notes.

Atomic Strucutre

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The notes we went over in class and once we finished with the notes Mr.Lieberman generously gave us ample amount of time to start our overflow of homework. Tonight's homework is to finish the labs, study for the quiz tomorrow, and a chemthink which is due on Monday.

Everybody don't forget to wear blue and gold tomorrow and show your titan spirit for the homecoming genie!
The next scribe will b.....Colleen Coleman

Oleic Acid Lab and Bohr Notes

Today was another exciting day in chemistry! We started off by finishing off some of yesterday's notes.

Atomic history day #2 1

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We got even further into atoms this afternoon by learning about Niels Bohr. Bohr introduced the Bohr Model in 1913, that is still widely used today. He discovered that the neutrons and protons lie in the center of the atom, a dense region called the nucleus, while the electrons are free to orbit the nucleus. The electrons circle around the nucleus much like the planets revolve around the sun, yet they are not confined to a planar orbit.






After we finished the notes, Mr. Lieberman reviewed yesterday's Rutherford Experiment. He gave us the correct formulas for finding the area of the circles and squares on the sheet, which are

(% dots in circles) x 602 cm^2=area of six circles

(% dots in squares) x 602 cm^2= area of six squares



Then we began our Oleic Acid Lab. Prelabs were checked in, and then we got in our lab groups to begin this exciting lab. First, we filled a dropper with methonal and counted the drops it took to fill 1 mL. We used this information to calculate the volume of a single drop of methanol.



We than took a lunch tray, cleaned it with warm soap and water, and filled it with cool water about 0.3 cm deep. We applied a thin layer of lycopodium powder and added 2 drop of a .500% oleic acid solution. Once this is done, we were instructed to measure 8 different diameters of the cirlcle that was formed, and averaged the diameters.

We didn't get any farther in the lab, because of time constraints. Tonights homework is to work on the lab (which is due Friday), but Mr Leiberman warned us that the calculations are extremely difficult.

Don't forget to wear your togas tomorrow so the homecoming genie pays us a visit! And, tomorrow's scribe will be Katie I.

Learning About Rutherford

Yesterday was a very eventful day in Period 6 chemistry! We began class by once again summoning the homecoming genie (he didn't show up). Shortly after, we began with some notes on Ernest Rutherford.

A student of J.J. Thomson, Rutherford started noticing that "alpha" particles were sometimes deflected by something in the air, and he couldn't figure out why. So he began his gold-foil experiments. He fired alpha particles at an extremely thin sheet of gold foil, and discovered that they were deflected through large angles and could even be reflected strait back at the source. This showed that most of the atom was empty, and there was a dense positive area in the atom (the nucleus).

Atomic history day #2 1

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After the notes, we took part in an interesting Rutherford Simulation modeled after the experiments Rutherford did when he discovered the nucleus. We got into groups of two and received papers, marbles, and carbon paper. Each sheet of paper had six cirlces on it with a tiny square in the center of each circle. We laid a peice of carbon paper (face down) on top of this sheet and dropped a marble on the paper about 200 times. This left each group with a sheet with 200 black dots scattered throughout the circles, squares, and outside edges.

We were challenged to use this sheet (and the dots that marked it) it estimate measurements for the areas of the circles and squares. The correct way to do this was to do

(% dots in circles) x 602 cm^2=area of 6 circles, and the same for squares, just replacing the percentages.

The nights homework was to work on this expirement for Friday, Oleic Acid Prelab, and the Chemthink.

Atomic history day #1

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Atomic history day #1

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The Homecoming Genie

1. Today in our chemistry class, Mr. Lieberman introduced us to the Homecoming Genie. The genie only comes out of its silver bottle once a year around homecoming! He got the genie from his high school chemistry teacher so its an old tradition. He told us that the Homecoming Genie would only come out if we had enough homecoming spirit. Even after he called the genie it still wouldn't come out, so we didn't have enough spirit yet! Hopefully it'll come out tomorrow if we all wear green and silver! After we experienced the homecoming genie, Mr. Lieberman started discussing the alchemy notes (as seen in the above post) with us. He discussed how the alchemists laid the basis for the foundation of chemistry today. They tried to do experiements like turn metals into gold and make immortality potions. Even though these experiments failed (obviously) for the alchemists, the did contribute greatly to science. They discovered:

• elements such as mercury and sulfur


• developed new glassware


• developed new lab procedures (wearing safety goggles)

We learned about the atomic theory:

• Law of Conservation of Mass: Mass is neither created nor destroyed during chemical reactions


• Law of Definite Proportions: a given chemical compound always contains the same elements in a specific proportion by weight.


• Law of Multiple Proportions: when two elements combine to form one or more compounds the weight of one element combined with the fixed weight of the other element are in a ratio of small whole numbers

We learned specifically about a few important early alchemists:

Robert Boyle : developed theories about elements- an element is a pure substance that cannot be broken down into other substances

John Dalton: built on the atomic theory-

• elements consisted of tiny particles called atoms


• elements were pure because all atoms in one element were identical and had the same mass


• elements differed because their atoms had different masses


• compounds consisted of the atoms of different elements combining together


• Atoms:small,indivisible, indestructible particles that had their mass, behavior and size based on what element they are

J.J. Thompson: made the cathode ray: tube with a small amount of gas inside (lead to television)

• he discovered electrons when he used a magnet to attract/repel the electricity inside the ray


• came up with the Plum-Pudding Model:

  

So.. that's what we did on September 27th in Mr. Lieberman's Honors Chem class.. Don't forget your green and silver tomorrow so we can see the Homecoming Genie!! ~Korri Hershenhouse

PS. The next scribe will be Ellen H!!