3 Qs

Recently I've learned about thermodynamics and how to solve for the entropy and ethalpy. Also about Gibbs law. In anatomy I just finished a claymation on muscle contraction. I plan to study thermodynamics over the break so I don't forget anything when I come back next semester.

Three Questions

Recently Iv'e learned about Hess's Law. We did a lab today that measure the enthalpys of different reactions; HCl and NaOH, NaOh and NH4Cl, and HCl and NH3. We measured the temperature change of two reactions and used Hess's law to determine the  the enthalpy change, delta H of a third reaction. I am understanding the calculations on how to figure out enthalpy and Hess's law. I hope to keep up my studies in this class and get at least a C in this class.

three questions

This week I learned about the sodium potassium pump. I learned how it is used as a electrochemical gradient in the body. As action potential moves throughout the cell acting as a domino effect, it occurs towards the direction of polarization. It occurs before the muscles can be stimulated again and the ionic concentration of the resting potential is restored by the sodium potassium pump. As the sodium enters the cell it has a reversal effect in charge and leads a change in the permeability momentarily. I have been taking my studies in chemistry to the next level. I come in during lunches and work on notes or worksheets. I ask more questions now in class and I read the book and study for about two hours a night at home. I hope to continue this work and make a drastic improvement in my grade. 

3 Questions

Recently I've learned about gas laws in chemistry class. I learned more about Boyle's law, Charles law, and avogardo's law. I also learned about Dalton's law of partial pressure. In anatomy I am learning about the skeletal system. And I am hoping to finally get strapped down and focus on getting better grades in my Ap chem class.

Battery Water Electrolysis

• How do the electrons flow through a voltaic cell (i.e., a battery)?
• Why is a salt bridge necessary?  What types of salt solutions are most useful within salt bridges? (What's the most important characteristic of these solutions?)
• What is the difference between an anode and a cathode?
• Where does the oxidation and reduction occur in a battery? 
  How is the redox half-cell related to both the flow of electrons and the cathode and anode?

http://ts2.mm.bing.net/th?id=HN.608000875050765589&pid=15.1&P=0

In spontaneous oxidation-reduction reactions, electrons are transferred and energy is released. If electrons flow through n external device energy is produced. Electrons only spontaneously flow from higher to lower potential energy. The salt bridge is a U-Shaped bridge to keep the balances charged. The cations move towards the cathode and the anions to the anode. An anode produces oxidation, while the cathode produces reduction. The redox half cell related to both the flow of electrons and the cathode and anode. The strongest oxidizer has the most positive reduction potentials and the strongest reducers have the most negative oxidizers. The greater the oxidation difference the greater the U.

For more information about Voltanic cells visit:

http://chemwiki.ucdavis.edu/Analytical_Chemistry/Electrochemistry/Voltaic_Cells

3 Q's

Recently I have learned the voltaic cell in my AP Chemistry class. I learned about being spontaneous and non spontaneous cells and how they react and function.I learned about the battery and how non-spontaneous reactions need a source of energy to balance their electrons. I just completed a lab on bones and finding out which ones which by clues. And also a lab on the electrolysis of water. which we concluded to be non spontaneous and it required a battery to produce the gases. I hope to do good on my retakes for chemistry.

3 Q's

Recently we completed a lab on calculating the percentage of H2O2 in a drugstore bottle of Hydrogen Peroxide. I actually completed the opposite experiment. Instead of titrating the KMno4 into the H202,  I titrated the H2O2 into the KMnO4.  I've learned about acid base equations, and titrating equations. Im planning on stepping up my game and dong everything in order to raise my grade in this class.

Determination of an Activity

 

The objectives of this explorer labwas to derive activity series, describe oxidation and reduction reactions by writing net ionic equations. Metals will loose electrons as easily as others will, thus explaining while they aren't all active. A replacement reaction is the replacement of  elements in compounds. A redox reaction involves the transfer  of electrons between two compounds. Metals have different reacttivity. They are ranked  by the highest reactions to the lowest;

3 Q's Blog

Recently we preformed a titration lab and have been working on acid-base equations. I have learned a lot about acid-base equations, and most recently about Redox equations.  I am really understanding the redox and oxidation equations. I plan to get a better grade in this class and i will put  in so much effort to make that happen.

Tirtration Explorer Lab

• What is the empirically determined concentration of a given sample of sulfuric acid?

A Bronsted-Lowry acid-base reaction witch transports a H+ ion from one molecule to another. A stronger acid will contain more H+ ions and the base will have less. The acids are "donors" while the bases are "acceptors"  Strong acids dissociate into weak conjugate bases, and weak acids dissociate into strong conjugate bases. All acid base equations react into a neutralized reaction. They are ionic meaning the H+ atoms increase, but do not change the number in Oxygen. Titration is a method for quantitative chemical analysis of unknown concentration of an identified component.  The empirically determined concentration of a given sample of sulfuric acid  is

Three Questions

Recently I just preformed a lab on electrolysis of water. We've been studying solutions and colloids and the Tyndall effect. I am understanding the concepts and ideas established in this lesson. I hope to continue to build my knowledge in chemistry and get better with my stoichemotery.

Electolytes and Water

Recently we worked with ionized and deionized water. We had to recreate the three different types of the ionized water. One was just distilled water, the other had a low concentration of electrolytes, and the other was comprised of a high concentration. We found out that the increase of salt gave the water a higher concentration, and the addition of distilled water lowered it. The electrolytes are ionic compounds containing both cations and anions that were dissociated in the solvent. The solvent produced negative and positive charges and conducted electricity. A solute is what is dissolved, hence the salt, and the solvent is what does the dissolving. A solution is a homogeneous mixture of two pure substances. An example of a particle diagram  would show that the Cl-ions are attracted to the hydrogen atoms and the Na+ atoms are attracted to the oxygen atoms.

There are two different concentrations of salt solutions that can be qualitatively demonstrated in the pictures shown below. By adding less salt to the beaker of water, we were able to cause the light to become dimmer. If we added more salt to  the water the light would become brighter. You can mathematically show the difference in concentration by finding the molarity. For example, you  can use moles of salt all over the liters of the solution for molarity. You can also use the  and also moles of salt over the kilograms of water. To figure out which beaker is the distilled water, low concentration, and high concentration, you use a electricity conducting tool which will show you the amount of electricity that was produced. Obviously the DI water had no ionization within it, so there was no electrolytes. The salt water contained cations and anions, and had a high concentration, because of this the electrolytes and water were attracted to the salt.  The tap water is ionized, but due to a low concentration, it didn't produce a lot of electricity.

These and Those Lab

Our last lab was the These guys and those guys. It was the combination of the sodium bicarbonate and acetic acid, otherwise known as baking soda and vinegar. we observed to see how much O2 and H2O we could produce. The chemical reaction is 
NaHCO3+HCH3COOH—>CO2+H2O+NaCH3COO.

We performed multiple attempts during this lab, but I was only present for one of the days. We used a variety amount of baking soda between (.25-4.00 grams) and adding it to two finger width amount of baking soda . We found out that the limiting reactant is the vinegar because of the increase of baking soda. Our experiment results produced to much CO2 and didn't react fully. 

This experiment helped verify stoich relationships and to review limiting reactions. Using the masses obtained from the experiment it is possible to calculate the theoretical number of grams produced and/or lost, therefore verifying the stoich relationships.

Three Questions

Recently we completed the baking soda and vinegar lab.  We have also been reviewing and reviewing stoichemetry, and moles. Tomorrow we have a test and I'm extremely nervous. Hopefully I will remember what to do, the math and get an A.

Electrolysis of Water

In Chemistry class today I completed the Electrolysis of Water Lab. I measured about 40 mL of distilled water in a 50 mL glass beaker. I mixed about a 1/2 teaspoon of Epson salt in the distilled water, until it was a clear solution. I then obtained two small lass tubes and filled the tubes to the top with the distilled water/Epson salt solution Then, I grabbed the small medicine plastic cup with the two tacks punctured on the bottom and placed it so the prongs of the tacks were submerged into the test tubes. Then I quickly flipped the tubes and plastic cup over, and filled the cup with the solution, and placed it over a D battery. The test tubes caught the oxygen and hydrogen that was being produced. We then retested the experiment by adding a pH indicator which turned the test tubes two different colors. The balanced chemical equation that was produced was;

2H2O --> 2H2 + O2

There were two qualitative indicators in this experiment;  you can visually observe twice the gas that was produced in the Hydrogen tube than the oxygen tube and the color difference due to the pH indicator that showed the difference in the composition. Yes, you can collect quantitative data to 'prove' the balanced reaction because the one tube produced twice as much gas than the other which can be proved in the equation. The equation showed that there is a ratio of 2:1 Hydrogen to oxygen which was proved by the results of the test tubes.

First Set without pH indicator

Second set with pH indicator

MY Particle Diagram

Three Questions

Recently, I have reviewed over the nomenclature and basic knowledge of identifying compounds and elements and took it to a better understanding. I completed an experiment that also helped me build my knowledge about matter composition and chromatography. I've reviewed a lot this past week, as well as learned new vocabulary. I am planning to continue building my knowledge in chemistry at a different stance. Learning new and more complicated knowledge about chemistry in a faster, more complicated pace. I'm excited to hopefully excel in this class, learn a lot of science, and it's going to take a lot of long nights, stress and hopefully I can come out and pass this AP Chemistry test.

Paper Chromotography

Dear Dad,
I know how interested you are in Chemistry, and I'd like to tell you about my most recent experiment today in my Chemistry class. As you know, Dad, a proper experiment should follow scientific method, and today's experiment was no different. Much of our background was knowledge previously learned in science class. Our teacher, Mrs. Gardner, asked a question and formulated the hypothesis for us, We just listened, sat down and followed the instructions. We created cards made from filter paper, which served as our stationary solvent, to separate our different solutes. We also prepared three different solutions, to dissolve the various pigments found in common marker dyes.  We tested seven different markers, both colors and makers of markers.  We used a blue, orange, yellow, brown, black, red and green markers from two different companies, and similarly used seven different FDC dyes (these are the primary dyes used by marker companies to produce their markers by mixing these FDC dyes).  The FDC dye colors used were blue 1, blue 2, red 3, red 4, green 3, yellow 5, and yellow 6.  We spotted a total of nine paper cards with each color; three cards each with the two different markers, and three of the FDC dyes with all seven dyes from each marker. We used three different solvents; a sodium chloride solution, isopropyl alcohol, and a Chromatography solution, which were our mobile solvents, and our stationary solvent was the paper. The three different sets of solutes which were the dyes; Crazy Art Markers, Vis-à-vis Markers, and FDC dyes.  The markers were comprised of dye solutions and were put together physically, which was evident in the separation of colors on our paper matrixes. The dyes each traveled differently depending on which solvent was employed.  The chromatography solution was a nonpolar solvent. Since our pigment molecules are polar, there were unable to dissolve in the solvent. This is evident by our data of the chromatography set. None of the pigments were dispersal with this solution. The alcohol, was very slow.  The alcohol molecule has both polar and non-polar parts, but mainly a non-polar solution. The NaCl solution being polar, dissolved the pigment molecules the best, and was able to quickly diffuse up the filter paper.   Since the NaCl solution spread the pigments the fastest, we noticed the most blurring.  The pigment molecules were more muddled because they spread so quickly.  Since the alcohol spread the pigments more slowly, the pigments had time to stratify more completely, giving us the vivid strata of different colors in each pigment blend. In this case, the heavier pigments were able to separate from the smaller ones, and clearly visible bands of color were evident. The attraction to the solvent is because of the polarity. Like dissolves like. The quantitative data (Rf) for the Crazy Art with sodium chloride were calculated below;
       6cm/6.5cm=.9230=.9
       2.2cm/6.5cm=.3384=.3
       1.8cm/6.5cm=.2769=.3
As you know Dad, the Rf is the distance of my component to distance of mobile solution. We measured from the .5cm line to the middle of the bulk of the solution, and divide that by the distance from the .5cm line to the solvent front line. A lot of the solutes stopped before the other solutes. This is due to their mass. While the lighter mass dissolves quicker, the heavier mass dissolves slower. The qualitative data that was observed in this experiment somehow used the same three different color pigments. For example in the Crazy Art/ Alcohol , the blue on #10 got darker, #9 went from and orange/yellow to a pink, and the black marker color on #6 went from black to brown to orange to red to purple, then blue. The reason why some of the dyes traveled further  than others is simply due to the chemical composition of mass. As I said before, lighter mass is quicker travel, when denser mass causes a slower travel speed. The chemical components of the solutions also played a key role to why some of the solutes traveled slower than than of others. This is due to nonpolar and polar attractions.
THis lab helps reinforce my previous understandings about chemical/physical changes and properties. We didn't use any type of chemical change or properties, because we were dealing with solubility. Which you know, Dad, is ALWAYS a physical combination of matter. We also reflected on matter classification and how matter affects the solubility and distance the pigments travel. And the separation techniques, were physically noticeable. We were able to separate the dyes from each other . Well, in other words we had fun. It was a neat experiment to start our class on. See you next time,


Love,
Mason