Estepr Theory Lab

All standardizations are performed in triplicate. Weigh out .1000-.1200 gram KIO3. Add 70-80 mL of deionized water. Swirl and dissolve. Add 3 mL of 6M HCl. Swirl and mix. Quickly titrated the brow-red solution with 0.1M Na2S2O3 until it is light yellow. Then add 3.5 mL of starch indicator. Titrate again until the dark color first disappears.

6-3: This process is used by cells to manufacture _biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products__

For the lesson observed the objectives was to explain the trends of the periodic table based on the elements’ valence electrons and atomic numbers. Additionally, students were responsible for applying their previous knowledge in calculating subatomic particles to review the Bohr Models and discus the relationship among families in the periodic table. Students will use the information from today’s lesson to make future judgments on reactivity and bonding created during chemical reactions in the next unit. Lastly, students were to connect the information on elemental properties to previous experiences with their health, commercial products, and everyday life.

The students created a macroscopic, three-dimensional (3D) model of several properties of the periodic table. They explained in their own words the following terms: atomic radii, ionic radii, first ionization energy, and electronegativity. Lastly, they identified, described, and explained the patterns observed in the 3D periodic tables for the following element properties: atomic radii, ionic radii, first ionization energy, and electronegativity.

Part 1: Esters aromas are very distinct and often pleasant, they are often used in food aroma and fragrances.1 Esters chemical properties are distinguished by their low molecular weight and low boiling points, caused by their dipole-dipole and dispersion interaction.2 Esters are the result of a condensation reaction, in which a carboxylic acid, an alcohol, and an acid catalyst react to create a water molecule and an ester.

Directions: Read/ Study all the lesson information in the 5.03 lesson then click the activity tab to perform two virtual labs. (There are recorded Teaching Videos for lesson 5.03. To view them click the “Help Sign” on the announcement page. Next scroll down to Lesson 5.03 stuff and you should see 5 part video links that will cover the lesson content.)

pH was recorded every time 1.00 mL of NaOH was added to beaker. When the amount of NaOH added to the beaker was about 5.00 mL away from the expected end point, NaOH was added very slowly. Approximately 0.20 mL of NaOH was added until the pH made a jump. The pH was recorded until it reached ~12. This was repeated two more times. The pKa of each trial are determined using the graphs made on excel.

The data gathered and calculated in the experiment accurately portrayed the way the reactions would have taken place. The chloride analysis was a little bit off from other groups due to the fact that our AgCl was in clumps, creating less surface area, thus our product took longer to burn and may not have burned correctly compared to other groups; yet there are several experimental factors that could have caused us to have different results than other groups, i.e. different measurements for samples. Our sources of error could have included eye measurement error, timing of set solutions error, measurement errors, and small calculation errors. Among other variables, the calibration of the analytical balance and spectrophotometer could have

What is the molecular geometry around a central atom that is sp2 hybridized, has three sigma bonds, and one pi bond?

Day 1. Michael was coming home for vacation from college. When he got home he found out that

33. Electron dot model is a way of representing the valence electron of an atom.

The book “The Periodic Table” by Primo Levi is undoubtedly a masterpiece. It showcases the enthusiasm, the level of dedication, and passion successful chemists such as Primo Levi himself had for the field of their expertise. The way Primo Levi has related the troublesome times and events he had to face in prospect with the elements of the periodic table is laudable. Primo Levi is surely an inspiration and a perfect example of prodigy and passion. Despite the challenges and the hardships inflicted on him by the bigoted group of Germens, he still managed to emerge as an exceptional chemist and an author who made great contributions to the modern chemistry as we now know it.

Aromatic compounds can undergo electrophilic substitution reactions. In these reactions, the aromatic ring acts as a nucleophile (an electron pair donor) and reacts with an electrophilic reagent (an electron pair acceptor) resulting in the replacement of a hydrogen on the aromatic ring with the electrophile. Due to the fact that the conjugated 6π-electron system of the aromatic ring is so stable, the carbocation intermediate loses a proton to sustain the aromatic ring rather than reacting with a nucleophile. Ring substituents strongly influence the rate and position of electrophilic attack. Electron-donating groups on the benzene ring speed up the substitution process by stabilizing the carbocation intermediate. Electron-withdrawing groups, however, slow down the aromatic substitution because formation of the carbocation intermediate is more difficult. The electron-withdrawing group withdraws electron density from a species that is already positively charged making it very electron deficient. Therefore, electron-donating groups are considered to be “activating” and electron-withdrawing groups are “deactivating”. Activating substituents direct incoming groups to either the “ortho” or “para” positions. Deactivating substituents, with the exception of the halogens, direct incoming groups to the “meta” position. The experiment described above was an example of a specific electrophilic aromatic

However, in 1957, Ronald Gillespie and Sir Ronald Nyholm, an Australian chemist, changed this proposal to build a more detailed theory. This theory, known as the VSEPR Theory (Valence Shell Electron Pair Repulsion) states that the atoms in a molecule will achieve a geometry that minimizes the repulsion between the electrons in the atoms and the molecular shapes can be predicted from their Lewis structures (diagrams that show the bonding between atoms of the lone pairs and molecules of electrons that may exist in the molecule.) Another expertise of Gillespie’s was the Kepert Model. The Kepert model is an alternation of the VSEPR Theory. Except, in the Kepert model, the metal lies at the center of the sphere and the ligands are free to move at the surface of the sphere. Lastly, the model ignores all non-bonding

     Kekule and Couper’s theory was not all without fault; it is suprising that they did not recognize atoms as three-dimensional objects if they were to be understood as true particles of matter in space. It was not until 1875 when van’t Hoff and LeBel proposed their hypothesis of compounds and atoms taking up space. Their hypothesis went as follows: Four bonds of carbon were located at equal angles to each other in space, this would be a rectangular tetrahedron. Immense amounts of proof have been supplied to support this theory, but is not universally accepted. It is believed today that this hypothesis is pure nonsense, proving that van’t Hoff and LeBel were misdirected. It goes to show science is not