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Sabah Hussain 403
Transcript of Sabah Hussain 403
-Potassium iodide 0.1% solution,
-Hydrogen peroxide 3%,
-Sodium thiosulfate 0.001 M,
-Hydrochloric acid, 0.1 M,
Distilled water (1 gallon)
Micro-titer plates (It would be best if they're white/transparent)
Stopwatch or other some other sort of timing device
White piece of printer paper
Safety glasses (For personal protection)
Latex gloves (For personal protection) Conclusion Hypothesis So what happens during my experiment is….
1. Colorless chemicals are added together.
2. There’s no visible change at first---- it’s transparent.
3. After a moment of patince, the liquid solution turns into a dark blue complex. Le Chateliers Principle La Chateliers Principle states that when a change is made to a reaction, the reaction will react to it by opposing it. 7. Pay attention at all times. 5. Wear old work clothes.
6. Ask your parents permission to be working with chemicals. Why is the Iodine Clock Reaction so notable? The Iodine Clock Reaction What is the Iodine Clock Reaction?
Iodine is a element in the periodic table.
Chemical Kinetics, or Kinetics is the study of the rates in which chemical processes take place.
In this project I was to try to understand what happens during the Iodine Clock Reaction.
I 3- (aq) + 2 S2O^3 - (aq) -----> 3 I (aq) + S4O6^2- (aq) Now for the exiciting part............. 1 3- + starch -----> (1 3- starch complex) Background Research
-Chemical kinetics or reaction kinetics is the study of the rates in which chemical processes take place.
-Chemical kinetics also help gain information about the reactions mechanism and transition rates in a chemical reaction. In short....... Law of Mass Action Activation Energy Collision Theory.... Reaction Mechanism Transition State Temperature Chemical Kinetics Physical state Concentrations Catalysts 1. Pictures of the Experiment 1.Wear gloves.
2. Your body should be covered.
3. Cover up your working area.
4. DO NOT DRINK ANY OF THE CHEMICALS. Roller Coasters: 23 The Iodine Clock Reaction has been used in Chemistry classes as it is rich in the element of drama. It is also a classical chemical reaction that displays the chemical kinetics in action. In the Iodine Clock Reaction, there are really two methods occuring simultaneoulsy. The first process is slow and produces the triiodid ion.
H2O2 + 3 I- +
2 H+ -----> 13- + 2 H20
The triiodide ion is a mixture of iodine and iodide. Basically meaning;
Hydrogen peroxide reacts with iodide ions in an acid solution to form triiodide and water. Triiodide has relationship with starch When they both react a dark blue
complex color is formed. The Iodine Clock Reaction Equation for reaction 2: -The reaction is so fast that none if the triiodide has time to form a complex with starch; even though starch is present in the reaction mix. In the second equation: - The thiosulfate is now consumed to make tetrathionate. Now that it is all used up; triiodide is able to react with starch. Which means.................... Almost done with the reaction process........ The starch reacts with the triiodide to form a blue complex! The faster the reaction in equation 1 goes, the faster the dark blue complex will appear. Overall............. Purpose The purpose of this project is to test and see what happens during the Iodine Clock Rection, and how levels of Hydrogen Peroxide affect it. I predict that the more the Hydrogen Peroxide drops I add to my experiment, the faster the Iodine Clock Reaction will proceed. According to sciencebuddies.org, "The rate actually depends on the concentration of hydrogen peroxide raised to a power, called the "reaction order."" Based on my background research, I can accept that fact; given that the reaction order is used in Reaction Rate Laws to indicate certain powers, and determine how important the concentrations are, in terms of how fast they go. The statement, "...how fast they go..," being how fast the reaction takes place, according to the amount of concentrations the reaction order represents. In all, I believe that the amount of Hydrogen Peroxide added to my experiment will hasten up the chemical reaction process, causing the mixture and appearance of the dark blue complex to appear sooner, compared to my experiments to be done with a low concentration and low amounts of Hydrogen Peroxide. Materials/ Apparatus My control Variable:
4 drops of the potassium iodide (KI) solution, 2 drops of hydrochloric acid, 1 drop of starch solution, 1 drop of thiosulfate solution
My independent variable:
Amount of Hydrogen Peroxide
How fast the reaction proceeds with different levels of hydrogen peroxide
Seconds Step 1: Take all the necessary precautions needed for protection. It's urged that you wear gloves and safety glasses.
Step 2: Determine your work area and cover it up with unneeded material. Using old newspapers, rather than throwing them way, would be a good Eco-friendly and smart choice.
Step 3: Take the amount needed of each apparatus (chemicals), and prepare them for later use so you won't be to and fro between the steps.
Step 4: Prepare a 1% starch solution by first dissolving a starch capsule, available to you in the Kinetics Reaction Kit, in a 50 mL beaker filled with distilled water.
1. For further analysis, it is best to take a drop of both the solutions, listed above, and mix the drops on flat piece of plastic wrap which should be on top of a white printer paper. Separate the drops roughly by 2-3 centimeters.
2. Observe the as the two drops collide against a white background, for most satisfactory results.
3. Experiments shall run in pairs (two wells per duplicate).
4. If the results are not precise, re-do the experiment for acceptable results.
Step 5: Use the following apparatus for the experiment in two adjacent wells: 4 drops of the potassium iodide (KI) solution
2 drops of water
2 drops of hydrochloric acid
1 drop of starch solution
1 drop of thiosulfate solution
8 drops of hydrogen peroxideStep 6: Now, mix thoroughly with a tooth pick.
Step 7: Start the timer and then begin immediately as soon as the hydrogen is added.
Step 8: Keep track of the time, and it is vital to record the time in which you began to see the blue complex color developing, in your observation notebook.
1. Label this as, "lag time."
* Lag is a period of one event and another; in scientific terms2. Record the room temperature.
Step 9: From then on, you will continue the procedure but with one less drop of hydrogen peroxide and one more drop of distilled water.
1. Mix thoroughly with a tooth pick.
2. Start the timer.
3. Immediately stop and record the time when the solution turns, or begins to turn dark blue.
4. Record the room temperature.
Step 10: Repeat step 9 until you reach up to using one drop of hydrogen peroxide.
Step 11: Repeat the whole procedure at least two more times with clean equipment or materials, to prove that the results are based on precision not luck. So when you're studying Chemical Kinetics, you're studying the reaction rate of a chemical reaction. Main factors that influence the reaction rate: 1. Physical state of the reactants
2. Concentration of the reactants
3. Temperature at which the reaction occurs
4. Whether there are any catalysts present in the reaction Chemical Kinetics Physical State:
-When reactants are in the aqueous (aq) solution and thermal motion brings them together. Concentration:
-The Collision Theory states that the reaction rate increases with concentration. Temperature:
-When you heat something, you make the molecules move faster; given that you are providing them thermal energy.
-Temperature usually has a big impact on chemical reactions. Catalysts:
-Catalysts increase the reaction rate by providing a different reaction mechanism; but with a lower activation energy. Collision Theory........ The Collision Theory states that in the process of chemical reactions, molecules must collide in order to react together. The reaction mechanism of a chemical reaction or chemical transformation, is a step-by-step thorough method that tells exactly what's happening through the procedure until a chemical change occurs. During the transition state two thing happen: -A statse in which An unstable arrangement of atoms exist only for a few moments during a chemical reaction.
-Highest point of energy formed during a chemical reaction Continuation on the Transition State Theory During the transition state an odd activated complex molecule is formed. It has some partially formed and partially broken bonds. This theory suggests that there are 3 major factors that determine is a reaction will occur or not. Basically; the Transition State Theory suggests of two possible outcomes: -A return to the reactants
-A rearranging of the bonds to form the product H2O Molecule Rearrngement The Law of Mass Action states that the rate of any given chemical reaction is similar to the product of the concentrations of the reactants. The law can be represented in a simple chemical reaction equation. aA+bB-------> cC+dD What really happens... Conecpt propsed by Svante Arrehenius
The "Activation Energy," is the minimum amount of energy that must be overcome for a chemical reaction to occur A graphy protraying what happens during a reaction SAFETY COMES FIRST Observations Bibliography: Graphs/Data: 8 drops of hydrogen peroxide- The reaction occured very fast. In fact, it was hard to exactly stop the stop-watch at the exact time. It occured almost instantly. 7 drops of hydrogen peroxide- Even though I decreased the amount of hydrogen peroxide by only 1 drop---- the results we're dramatic. When I had added 8 drops of hydrogen peroxide, the solution turned dark blue almost instantly. However, when decreased the amount of hydrogen peroxide by only 1 drop, the lag time was greater. 6 drops of hydrogen peroxide- I'm really surprised. The lag time is even greater than before. Just a few drops less of hydrogen peroxide is already making a big difference. 5 drops of hydrogen peroxide- There is no significant increase of the lag time. It certainly is taking a lot longer for the dark blue complex color to appear. 4 drops of hydrogen peroxide- As the amount of hydrogen peroxide is decreasing the solution isn't appearing instantly. The solution first turns into a tint of baby blue, and then after a while, it begins to turn into a dark complex. 3 drops of hydrogen peroxide- The range for the Iodine Clock Reaction is now about 30-40 seconds; meaning that the lag time has increased alot. I have also noticed that, as the drops of hydrogen peroxide decrease, it takes more time for the reaction to occur. 2 drops of hydrogen peroxide- It took a long time, compared to other trials before, for only a tint of baby blue to appear, and another 5-8 seconds for it darken. 1 drops of hydrogen peroxide- It took a VERY long time for the reactions product to become to the naked eye. The lag time, was by far the greatest. "Reprogramming and Somatic Cell Nuclear Transfer (SCNT)." Somatic Cell Nuclear Transfer (SCNT). N.p., n.d. Web. 19 Nov. 2012. <http://hesc.stanford.edu/research/programs/scnt.html>.
"Introduction to Chemical Kinetics, First Order Precesses, Half-Life." Introduction to Chemical Kinetics, First Order Precesses, Half-Life. N.p., n.d. Web. 19 Nov. 2012. <http://www.chem.arizona.edu/~salzmanr/480a/480ants/kinintro/kinintro.html>
"Clock Reaction - UW Dept. of Chemistry." Clock Reaction - UW Dept. of Chemistry. N.p., n.d. Web. 19 Nov. 2012. <http://depts.washington.edu/chem/facilserv/lecturedemo/ClockReaction-UWDept.ofChemistry.html>.
"Iodine_clock." Iodine_clock. N.p., n.d. Web. 19 Nov. 2012. <http://group.chem.iastate.edu/Greenbowe/sections/projectfolder/flashfiles/kinetics2/iodine_clock.html>
"Harcourt Essen Sodium Thiosulphate Iodine Clock Reaction Essays and Term Papers." Harcourt Essen Sodium Thiosulphate Iodine Clock Reaction Free Essays 1. N.p., n.d. Web. 19 Nov. 2012. <http://www.studymode.com/subjects/harcourt-essen-sodium-thiosulphate-iodine-clock-reaction-page1.html>.
"Cornell : CHEM 342132 : Lab 6 Chemical Kinetics Iodine Clock Reaction." Cornell : CHEM 342132 : Lab 6 Chemical Kinetics Iodine Clock Reaction. N.p., n.d. Web. 19 Nov. 2012. <http://www.coursehero.com/file/72148/Lab-6-Chemical-Kinetics-Iodine-Clock-Reaction/>
"Home Version of the Iodine Clock Reaction." Home Version of the Iodine Clock Reaction. N.p., n.d. Web. 19 Nov. 2012. <http://www.sciencebob.com/experiments/iodine_clock_reaction.php>.
"Iodine Clock Simulation by Gary L. Bertrand." Iodine Clock Simulation by Gary L. Bertrand. N.p., n.d. Web. 19 Nov. 2012. <http://web.mst.edu/~gbert/IClock/IClock.html>.
"Shodor." : A National Resource for Computational Science Education. N.p., n.d. Web. 19 Nov. 2012. <http://www.shodor.org/>.
"Iodine Clock Reaction." Nuffield Foundation |. N.p., n.d. Web. 19 Nov. 2012. <http://www.nuffieldfoundation.org/practical-chemistry/iodine-clock-reaction>. My hypothesis was supported with my data and results. I had predicted that the more the hydrogen peroxide there is in a solution, the faster the reaction shall occur. Basically, I followed the same general procedure for making the recipe for the Iodine Clock Reaction; except, as each passing trial, I decreased the drops of Hydrogen Peroxide. To record my results, and to see change in the lag time, I timed my experiments; so whenever a tint of baby blue appeared, the recorded that time. The experimentation showed that the lesser amount of hydrogen peroxide there is present in the Iodine Clock Reaction, the longer it will take for the reaction to occur. Conclusion (continued) Drops of hydrogem peroxide There were two trials connducted Average 1 2 3 4 4 drops of the potassium iodide (KI) solution
2 drops of water
2 drops of hydrochloric acid
1 drop of starch solution
1 drop of thiosulfate solution
8 drops of hydrogen peroxide For the Iodine Clock Reaction, you need.......... I had originally thought that hydrogen peroxide will help the reaction occur faster because it is an acidic solution with high amounts of concentration, which, according to my background research, greatly contribute to the reaction rate of a chemical reaction, in this case, the Iodine Clock Reaction. In this project I learned that the Iodine Clock Reaction is not as simple as it looks. In fact a lot of processes and steps have to happen inorder for the chemical reaction occur. With the element of drama by it's side, no wonder the Iodine Clock Reaction captures its audiences attention. I was really amazed when I researched the endless concepts that are needed to understand the Iodine Clock Reaction fully. My experiment went smoothly, for the most part. There were little errors and mistakes, however. At one point during the experiment, I even forgot to record the lag time. There was no spillage of the chemicals; the secret to that was that I always paid close attention. (Keep in mind that these chemicals are poisonous.) Lastly, I also covered my work area where the experiment was to take place, because this way, if a chemical did spill; no imminent harm will be present. The Lag Time of the Iodine Clock Reaction Affected by the Amount of Hydrogen Peroxide Drops: