Wednesday, March 23, 2011

Yeast Beast Lab Investigation

Title: Yeast Beast in Action Lab

Problem: How does yeast impact pressure and acid & base levels?

Hypothesis: When the yeast is added, the pressure level will rise, and the acid and base levels will skyrocket.

Materials: 1 computer
1 Vernier computer interface
1 Vernier Gas Pressure Sensor
1-hole stopper assembly
10 mL graduated cylinder
3% hydrogen peroxide
Yeast suspension
3 test tubes
1 test tube rack
1 eye dropper
3 mL of acidic mixture (diet soft drink, preferably coca cola)
3 mL of neutral mixture (skim milk)
3 mL of basic mixture (stomach antacid)
3 sticky notes (with a writing utensil)
1 250 mL beaker
20 mL of tap water
1/2 teaspoon of yeast
1 teaspoon

1) Obtain all washed and dried materials on a solid, level surface. It is strongly suggested to wear goggles for safety, but it is not required.
2) Connect the black stopper to the gas pressure sensor, which will then be attached to the computer interface. Open Logger Lite from the Vernier data-collection program and search the computer for a file labeled “24 Yeast Beasts” from the Middle School Science with Vernier folder.
3) Obtain 3 test tubes and a test tube rack for sturdiness. With sticky notes, label each clean tubes with A, N, and B (for acid, neutral, and base), assigning one letter to each tube. This will annihilate any future confusion as to which one is which.
4) Add 3 mL of hydrogen peroxide to each tube, carefully measuring and analyzing each measurement at a level height to receive the most accurate results.
Add 3 mL of each mixture to its test tube.
Using a 250 mL beaker, measure 20 mL of water and add one half tsp of yeast to the mixture. Stir with the teaspoon until properly blended.
7) Add 2 eye dropper units of the yeast and water mixture into Test Tube A.
8) Insert the black rubber stopper into the test tube.
9) Vigorously twist the stopper on to fasten for an airtight fit.
10) Click the collect button to begin data collection. Note: It is vital to keep pressure on the top of the stopper while the yeast takes effect in the test tube.
11) Test the data and record he highest pressure and at what time that it was documented. Do not disturb the contents of the tubes or computer until the data is collected.
12) Repeat steps 6-11 until all three tests are completed.
13) Save all information and disconnect all tubing and cords only to return them to their original compartments.
14) Make diagrams of the experiment.

Results and Conclusion:

The above table displays how much of the 3% hydrogen peroxide solvent and quantities of the mixture (whether it be diet coca cola, skim milk, or stomach antacid) is combined while in their test tube containers. For visual purposes, the chart also marks the letter with its corresponding material (in this case, an acid, neutral, or base). In this experiment, 3% hydrogen peroxide was tested with each type of acid/base. In Test Tube A, diet Coca Cola was integrated with the H2O2 (3% hydrogen peroxide) solvent. Once the yeast solution was fabricated and 2 eye drop units were added to the cylinder of glass, the black rubber stopper (connected to the Vernier Logger Lite Software) was firmly fitted on the opening of the tube to produce an airtight, secure seal. However, pressure was still needed to be placed on the top in order to restrain the cap from popping off. Although the procedure was to remain until the two minute mark, internal pressure prevented that from being the case, consequentially shortening the testing period. At the 1.4 second indicator, the pressure from the yeast mixture combining with the peroxide and soft drink spiked at 137.86 kPa (pressure). Oddly enough, the chart shown on the computer interface displayed an odd dip at the beginning of the trial. This could have been representing the fact that more pressure needed to be placed at the top of the rubber stopper by making a significant note that a slight bit of air was being released at the top. This was immediately recovered, and the test resumed, allowing the pressure to make somewhat of a highly arched outline of the Vernier graph. The physical aspect, according to the naked eye, of the process came to a close when there were two distinct layers: one of pure coca cola solution and one of trapped gas in the soda’s bubbles. To sum the soda trial up, it was the experiment that produced the lowest yeast activity, according to pressure measurements, but the highest level of liquids/gases out of the three.

The neutral element in this experiment was the mixture of the yeast and water solution, 3% hydrogen peroxide, and 3 mL of skim milk. This too recorded results of a significant dip. Nonetheless, there was a sensible explanation of this occurrence which was described as the transfer of the rubber stopper; the stopper needed time to adapt to its new position and change in weight and pressure (from both the interior and exterior). Yet another variable that could have contributed to different results would be that the eye dropper was not exactly the most accurate measuring unit due to it inability to be completely consistent in its content dimensions. This physical reaction caused the two separate echelons (as described above) to become slightly less distinct due to its clear merging colors.

The last Test Tube contained the base and utilized the reaction between the stomach antacid, 3% hydrogen peroxide, and yeast and water solution to produce a final product with a very distinct layer of bubbles. This stratum could quite possibly be classified as taller than the liquid that it was buoyantly levitating upon (the solution). What was first thought out to be a potential candidate for the lowest activity of yeast pivoted to be the greatest activity, pressure measurement-wise, at least. It proved as a great success with a pressure peak of 173.05 kPa.

From this, we can conclude that, because antacids work directly as a medicine that controls the pH balance in a human being and stifles the pain of heartburn, it had the most effect as far as pressure goes because it was working as it would if swallowed. On the other hand, the amount of artificial sugar in the Coca Cola produced a large quantity of bubbles along with its high level of carbonation. In total, the experiment had a favorable outcome.

Thursday, March 17, 2011

Conservation of Mass Lab Investigation

Title: Conservation of Mass Lab Investigation

Problem: What products are being produced and can they be confined?

Hypothesis: When the pop rocks and baking soda is released into its corresponding solvent, then carbon dioxide will be transferred from the solute to the balloon.

Materials: 2 packs of Pop Rocks
1 full 20 fl oz of soda
2 balloons
1 narrow funnel
1 teaspoon
1 tsp of baking soda
50 mL of vinegar
1 graduated cylinder

Pop Rocks and Soda
1) Pour pop rocks into one of the two empty balloons.
2) Obtain a 20 oz bottle of soda.
3) With a little strength, attach the end of the balloon with the tip of the bottle at a slant, so as not to start the reaction at an inconvenient time.
4) Once this is completed, straighten the balloon so as to get a steady stream of pop rocks into the solute.
5) Watch and document how big the balloon grows, what happens to the pop rocks, and why this happened.
Note: Make sure to hold down the end of the balloon around the bottle opening in order to prevent it from flying off.

Vinegar and Baking Soda
1) Measure 50 mL of vinegar in the graduated cylinder by gently pouring the vinegar bottle into the lipped cylindrical plastic container.
2) Pour the 50 mL of vinegar into the empty soda bottle.
3) Next, connect the opening of the bottle onto the small end of the funnel, and pour one pack of pop rocks into the balloon.
4) Attach the balloon in the same manner as the pop rocks-filled balloon, tipping the bottle so that the baking soda does not accidentally fall into the vinegar.
5) Straighten up the balloon and allow the baking soda to flow into the solute.
6) Watch and document how big the balloon grows, what happens to the baking soda, and why this happened.
Note: Make sure to hold down the end of the balloon around the bottle opening in order to prevent it from flying off.

Results and Conclusions:
Pop Rocks and Soda
For this experiment, pop rocks were combined with the soda. In my case, the soda was Sprite. This could have been a crucial variable, considering that my group and I had the quickest and most fruitful results during the pop rocks trial. During this 5 minute time period (the amount of time it took the reaction to take place and completely settle), the reaction happened comparatively slow in contrast to the baking soda lab, which took about 30-45 seconds. After the reaction had commenced and the pop rocks were integrated into the liquid, they slightly raised the level of the Sprite. Also, there was a slight discoloration of the pop rocks and surface of the liquid; it had a brown hue to it while the gas was released and the carbon dioxide that was inside of the pop rocks were emitted and confined in the balloon. The green tint of the bottle could have skewed the actual results visible to the naked eye, however. At the 4 minute mark, there was a noticeable torrent of medium to small sized effervescence in one spot. As for the balloon, it only filled halfway and tilted to the side due to the limited amount carbon dioxide released. Since the balloons were too small to hold a whole pack of pop rocks, there was less gas to emit. Nonetheless, the balloon felt tightly compacted with gas. This proves that it was not a typical chemical reaction, rather, a physical reaction because the mass was not destroyed, only transferred. Consequentially, this first experiment proved the above hypothesis as correct. As for the problem, carbon dioxide was produced, and yes, it was indeed trapped inside of the balloon.

Vinegar and Baking Soda
Because there was some water remains in the empty Sprite bottle, there was an integration of vinegar and water, but not enough to make a terrible difference. However, this was still a variable worthy of notification. When the procedures were all followed through, and the chemical reaction was permitted to take its toll, the balloon filled up in as little as 30 seconds. This was a significant jump from 5 minutes to 30 seconds (approximately 1 minute to completely settle). Just before the amount of the carbon dioxide in the balloon stabilized, it deflated just the tiniest amount. This could have caused by the possibility that the section of attachment between the balloon and soda bottle was not completely secured, or loosened during the procedures process. As opposed to the previous test, this balloon filled up faster, produced more gas, and raised in a straight line due to the large quantity of pressure pushing up from the bottom. The reason why it produced more gas was because there was not as much of a limitation with the baking soda; each molecule collision between the baking soda and vinegar produced more carbon dioxide. One surprising fact about this particular experiment was that the liquid stayed pretty solid on the bottom, excluding the fairly large effervescence. Overall, this experiment also supported the above hypothesis.

Tuesday, March 15, 2011

Chemical Reactions and Temperature Lab Investigation

Title: Chemical Reactions and Temperature Lab Investigation

Problem: How does temperature affect chemical reactions, i.e. alka-seltzer tablets.

Hypothesis: When the beaker with the alka-seltzer tablet is heated to 50 degrees Celsius, the process will speed up significantly, and vice versa for the cold temperature trial.

Materials: 500 mL Beaker
1 Graduated cylinder
1 Vernier Lab Quest Mini temperature probe with Logger Lite software disk
3 Alka-seltzer tablets
1 Watch or clock
1 Hot plate (set on high)
3-4 Ice Cubes

Results and Conclusion: The cold temperature was tested first, in this particular instance. When the ice cubes were dropped, the water level only reached 175 mL, whereas the instructions in the procedures section suggested to use the dimensions of 266 mL. Nonetheless, this was one of the variables that might have affected the outcomes in the end ramifications. Once this was recorded, the tablet was gently dropped into the beaker so that no spillage would occur and cause for extra clean-up, and the beaker was scanned for any significant observations. One of the surveillances caught on to the seltzer’s patterns; the effervescence systematically raised to the surface until ice crystals formed. Approximately one minute into the experiment, the tablet began to rise about half-way as if to only skim the surface to see what the outside temperature was. It did not fully peak until later when it was too late, and the lozenge was disintegrated at one minute and thirty seconds. After the tablet was gone completely, a very active bubble residue was left in layers in the 500 mL beaker. The general uprising of bubbles continued. Larger bubbles that dwelled on the bottom of the container rose in a choppy manner alongside the edges of the lipped cylindrical glass, in contrast to the minuscule bubbles that gently ascended at a consistent pace in the center of the beaker. At the six minute mark, most of the activity had slowed down, and culminated in an accumulation of large bubbles on the perimeter. These globules concluded with ice crystals as a consequence of the cold temperature. To illustrate my point, batteries discharge quicker in a cold temperature than they normally would in a warm temperature. This is because reactions occur slower in tense, chilly climates than contracted, warm climates.

To conclude the first test, the gradual audio end (while the tablet fizzed, it emitted a definite audio susurration) died down about 3 minutes after the tablet was completely deteriorated. Temperature measurements were recorded at the start to be 13.4 C (and was also the highest temperature), with a low point of 6.2 (at 79 seconds), and a final product of 7.1 at 156 seconds.

The next step descending from a freezing temperature is room temperature. This test commenced with a degree of intensity of heat at 22.4 C. Once the alka-seltzer tablet plunged into the not-so icy water (due to the fact that it was cleaned out between each trial for the most accurate results possibly accumulated), the sizzle of the pastille reacted at a much faster rate, almost at double speed than the first. With a new record, the alka-seltzer fizzled until its end at roughly 30 seconds. It also pinnacled with a hazy water appearance visible to the naked eye. Taking into consideration the pattern of bubbles the previous test accrued, this trial also had stratums, ranging from thick to thin (with a mixture of both large and small bubbles). The difference comes in when discussing the placement of the ice crystals and effervescence. The medium sized bubbled formed a small patch of ice crystals directly in the center of the beaker and served as an unstable crust on top of the water-seltzer solution. All the while, petite bubbles gathered on the bottom with the exception of a slight ice crystal circumference, and gradually raised to the top in their normal, uniform velocity. Unlike the first experiment, this lab pilot had an almost definite audio end (even though it was louder while in the process), meaning that it had a precise crepitating elimination point that corresponded realistically with the termination of the alka-seltzer tablet. Once again, numeric results had a low extremity of 21.8 C at the end of the beta test (84 seconds), and an extended end point of 22.8 C at around 5 minutes.

Opposing both predecessors, the hot temperature test snowballed different results altogether. Following the directions in the procedures section, the container was set on the bunsen burner to reach the necessary temperature. Waiting for the solvent in the beaker with the probe peeping through the topmost echelon on the glass to reach 50 degrees Celsius was the one and only dull point in the third trial. Once the alka-seltzer tablet was added and the beaker was removed from the hot plate, a fragrance was omitted in the atmosphere that was similar to that of a burning liquid. And in less than 15 seconds, the capsule was completely disintegrated and practically dead silent, as far as fizzing goes. This was also the time that it took for all but a few of the bubbles to raise up to their repeated destination. There are always a few exceptions, nonetheless, those that could have been prevented due to variables blocking the pathway of a perfect science experiment. These variables may include the inconsistent position of which the temperature probe was placed in this and previous trials, as well as taking into consideration the tablet. Whether the tablet was whole or not could have impacted the experiment because the inside was exposed to oxygen, light, and any dust floating in the air at that particular time and place. On the other hand, the hot temperature test also cumulated specific heat intensity results including (but not limited to) the following: starting at 22.3 C, fabricating a high peak of 53.8 C at 1.5 seconds after recording, and finally an end conclusion of 50.2 C at 57.5 seconds. Therefore, the above hypothesis can be officially approved as not just theoretically, but also realistically correct.

Friday, March 11, 2011

Chem Think: Chemical Reactions

1) Starting materials in a chemical reaction are called reactants.

2) The ending materials in a chemical reaction are called products.

3) The arrow indicates a chemical change has taken place.

4) All reactions have one thing in common: there is a rearrangement in chemical bonds.

5) Chemical reactions always involve breaking old bonds, forming new bonds, or both.

6) In all reactions we still have all of the same atoms at the end of that we had at the start.

7) In every reaction there can never be any missing atoms or new atoms.

8) Chemical reactions only rearrange the bonds in the atoms that are already there.

9) Let’s represent a reaction on paper. For example, hydrogen gas (H2) reacts with oxygen gas (O2) to form water (H2O): H2 + O2= H2O If we use only the atoms shown, we’d have two atoms of H and two atoms of O as reactants. This would make one molecule of H2O, but we’d have one atom of O leftover. However, this reaction only makes H2O.

Remember: reactions are not limited to 1 molecule each of reactants. We can use as many was we need to balance the chemical equation.

A Balanced Chemical Reaction Shows:
a) What atoms are present before (in the reactants) and after (in the products)
b) How many of each reactant and product is present before and after.

10) So to make H2O from oxygen gas and hydrogen gas, the balanced equation would be:
2 H2 + 1 O2 = 2 H2O
Which is the same as:
# of Atoms in Reactants Element # of Atoms in Reactants
2 H 2
4 O 4

11) This idea is called the Law of Conservation of Mass.

12) There must be the same mass and the same number of atoms before the reaction (in the reactants) and after the reaction (in the products).

13) What is the balanced equation for this reaction? 2 Cu + 1 O2 = 2 CuO.

14) In the unbalanced equation, there are: Reactants = Products
Cu atoms-1 Cu atoms-1
O atoms-2 O atoms-1

15) To balance his equation, we have to add 2 molecules to the products, because this reaction doesn’t make lone oxygen atoms.

16) When we added a molecule of CuO, now the number of oxygen atoms is balanced, but the number of Cu atoms don’t match. Now we have to add more Cu atoms to the reactants.

17) The balanced equation for this reaction is: 2 Cu + 1 O2 = 2 CuO
This is the same thing as saying: Reactants = Products
# Cu atoms-2 = # Cu atoms-2
# O atoms-2 = # O atoms-2

18) What is the balanced equation for this reaction? (Use the table to keep track of the atoms on each side.)
1 CH4 + 2 O2 = 2 H2O + 1 CO2
# of Atoms in Reactants Element # of Atoms in Reactants
1 C 1
4 H 2
2 O 3

19) What is the balanced equation for this reaction? (Use the table to keep track of the atoms on each side.)
1 N2 + 3 H2 = 2 NH3
# of Atoms in Reactants Element # of Atoms in Reactants
2 N 1
2 H 3

20) What is the balanced equation for this reaction? (Use the table to keep track of the atoms on each side.)
2 KCLO3 = 2 KCI + 3 O2
# of Atoms in Reactants Element # of Atoms in Reactants
1 K 1
1 CI 2
3 O 3

21) What is the balanced equation for this reaction? (Use the table to keep track of the atoms on each side.)
2 Al + 2 O2 = 3 Al2O3
# of Atoms in Reactants Element # of Atoms in Reactants
1 AI 1
2 O 2


1) Chemical reactions always involve breaking bonds between atoms and rearranging them in a particular order to create the product.

2) The Law of Conservation of Mass says that the same atoms must be present in the product as they were in the reactants. This is a reworded explanation of the French Chemist Antoine Lavoisier in 1789, which simply states that mass is neither created nor destroyed in any ordinary chemical reaction. Also, “the mass of substances produced by a chemical reaction is always equal to the mass of the reacting substances.”

3) To balance a chemical equation, you change the coefficients in front of each substance until there are the same number of each type of atoms in both reactants and products.

Wednesday, March 9, 2011

Polymer Lab Group Investigation

Table 6: Haley C., Keara B., Holden L.

Title: Tacky Glue Polymer

Problem: How does the tacky glue change the physical and chemical properties of the polymer?

Hypothesis: When the white Elmers glue (polyvinyl acetate) is replaced with tacky glue, the end result of a polymer will ultimately be stretchier.

Background Info: Tacky glue is just a "white glue" that's made especially thick so that it will grab and hold onto things more rapidly than thinner white school glues (such as Elmer’s glue). Also a terminology for glue that has not dried, but does so after attached to the substances being held together in a clear and flexible manner. This, as well as other PVA glues (polyvinyl acetate) must be kept from freezing in a cold environment, otherwise it will not act according to original plan. Slight to obvious discoloration of items is one symptom of tacky glue gone bad, and will peel of of glass, metal, and plastic after dehydrated. It is not a standard request for archival items due to its pH neutral chemical property. Nonetheless, if a quick clean up is in order, soap and water will work perfectly. This type of glue is typically available at craft stores, hobby stores, fabric stores, or even at places such as Target, etc.

Materials: 1 Tacky glue - polyvinyl acetate
1 plastic spoon
1 200 or 250 mL beaker (Pyrex)
1 500 mL beaker (Pyrex)
1 plastic or glass stirring rod with bent tip
1 graduated cylinder
525 mL of water
2 tsp of Borax laundry detergent (hydrated sodium borate)
1 ruler (30 cm)
1 plastic bowl (or any bowl that can hold a decent amount of material)
1 square of paper towels (or any absorbing material used for cleaning)
1 refrigerator (with an average temperature of 1.7- 3.3 degrees Celsius)
1 flat surface (a table will do)

1. Arrange the materials to be used at the head or front of a flat surface.
2. Add 400mL of water to the larger beaker. Set the used beaker aside.
3. Pour about ½ cup of Borax into the plastic bowl.
4. Stir in two teaspoons of borax into the water bowl for about 30-60 seconds or until the solute has dissolved in the solvent. Set this aside for future applications.
5. Measure 40 mL of tacky glue and transfer it into the smaller beaker. Fasten the cap back on the glue when not pouring.
6. Add 5 mL of water, measuring with the graduated cylinder, to the adhesive.
7. Record any observations of physical or chemical properties.
8. Quickly sanitize and rid the stirring rod of any previous substances.
9. Give the Borax compound a brisk stir.
10. Blend the glue and water for about 30-60 seconds, or until fully integrated.
11. Record any observations of physical or chemical properties.
12. Calculate 25 mL of the Borax solution that was just stirred with the graduated cylinder.
13. Deposit the solvent matter into the small beaker.
14. Coalesce the two elements, both solvent and solute, with the stirring rod.
15. Examine its features and document the discovery, just before cleaning the materials.

Stretchy Test Procedures: One ruler and a flat surface (preferably a level table) is needed to perform this experiment. After the polymer has successfully been formed, and is set to a comfortable, pliable room temperature, the trial(s) may commence. Align the ruler with the edge of the table; have the side with the centimeters facing the edge. Mold the sticky substance into an oval shape. Firmly grasp the polymer with both hands, leaving about one to two centimeters of material between fists. Stretch the matter at a controlled pace so to be sure that observations are able to be recorded, as well as allowing the polymer to adjust to the change in physical properties. How do you know when to stop stretching? When the link between the two wedges disperse in thin filaments, or the bridge suddenly splits, then it is a definite sign to halt the operation and record significant data. Depending on the fiber being tested, another ruler may need to be added to the materials in order to document accurate measurements. However, this is just in case the polymer spreads wider than originally expected (30 cm). Also, this test will need to be reiterated two to three more times in order to regulate an average calculation of its break-point. Compare and contrast with previous test results, as well as separate experiments.

Rebound and Temperature Test Procedures: The rebound and temperature test allows scientists in-the-making to chronicle the physical and chemical properties of a polymer. The only materials needed for these two tests are one 30 cm ruler, a flat surface such as a completely horizontal table, and a typical refrigerator (with temperatures at approximately 1.7 to 3.3 degrees Celsius or 35-38 degrees Fahrenheit). In order to test out the heated (more or less likely to be room temperature), vertically hold the ruler so that the 30 cm mark is at the top, and 1 cm mark is on the bottom. Mold the polymer in the shape of a ball for accurate and consistent ramifications. From the top of the ruler, drop the ball and observe how high and in which specific direction it bounced. Repeating this process several times is a recommended solution when trying to find a reliable average height; reform into a ball after each test if needed. Record conclusions, especially why this event occurred and what the exercise proved. To evaluate how a frigid environment affects the polymer’s chemical properties, place the polymer (still in the shape of a ball) in the center of a shelf (if possible), and wait for roughly 10-15 minutes. Once the substance has been able to settle in the refrigerator, re-alter the shape so that its mold is consistent, and eliminates any distorting variables. Reiterate the process used for heat. Record vital results.

How does it work?
A polymer is a long chain of molecules.

If the long molecules slide past each other easily, then the substance acts like a liquid because the molecules flow. If the molecules stick together at a few places along the strand, then the substance behaves like a rubbery solid called an elastomer.

Borax is the compound that is responsible for hooking the glue’s molecules together to form the putty-like material.

Results and Conclusion of Tacky Glue Lab: Tacky glue is known for its thicker, hydrated attributes. These qualities are visible to the naked eye when the top of the glue bottle is unlatched and the substance is poured out in a slow manner. Once the 5 mL of water is added to the glue, it seems to settle down on the surface. This is a repeat of the previous polymer test with white Elmer’s glue. However, the difference soon becomes apparent when the stirring rod is put into use and the chemical properties of the tacky glue activate with the Borax and water solution, acting as a catalyst for the soon-to-be-established polymer. Approximately 30-60 seconds of effortless stirring brings about a visual of altered adhesive clinging to the side of the container and an easily cleaned stirring rod. This extremely contrasts with the opposite experiment where the paste stuck to just about everything it came in contact with, such as glass, metal, skin, and paper. The tacky glue polymer was actually “picky” when choosing what materials to cling to, which included skin, paper towels (because of their texture), and itself. When it originally emerged from the beaker, it had bubbles attached to its exterior. This could possibly be due to the Borax mixing with water, a solvent mixing with a solute, thus creating bubbles from its soapy features. Because tacky glue is hydrated, it left the experimenters with a leaking solid that emanated glue. This excess substance was disregarded and was left in the glue’s original container, which had a large remainder to foggy liquid that did not set in with the polymer at the beginning. Yet another observation that was recorded was that the polymer slid smoothly off of the stirring stick, in variance with the Elmer’s glue lab, which roughly was torn off of the stick. It’s physical features when moist include a lumpy, slimy, waterproof-like, and somewhat less adherent texture. When dried, it gives the polymer a chance to express its capabilities to become more compact and depict a more solid image. Nonetheless, when stretched, the tacky glue substance appeared to have a central fiber, surrounded by sludge made from saturated glue and Borax, and was not a success in the Stretching Test, reaching a maximum limit of 23 cm in length. Once it was permitted to resolve on a balanced surface for about 5-10 minutes, it stretched to a total of 18 cm. Also, the rebound factor was determined at a height of 8-11 cm. The opposing polymer yielded results of 7-13 cm in height. This small difference could possibly be the aftermath of two polymers made out of the same form of PVA glues (polyvinyl acetate), where one is hydrated (tacky glue) and the other is not. After spending approximately 10-15 minutes in a 1.7 to 3.3 C degree refrigerator, the consequences (physical and chemical property change) were outstanding. When stretched slowly, it reached a height of 12 cm. However, this was not what excited us. The fact that we needed two rulers to measure the length of the stretched out polymer, which measured an average of 50 cm and reached a maximum of 59 cm) was incredible. It is important to make note that to reach such dimensions required equal tug force from both ends, as well as a leisurely speed in which to keep constant. This suggests that not only is the tacky hydrated glue stretchier, but also works better when left to dry, whilst Elmer’s glue (a much thinner adhesive) is more pliable when wet. Any variable that might have effected this experiment in particular may have involved the surface that it was bounced on (for the Rebound Test), the distance away from the ruler in which it was held (Stretch Test), and the overall amount of added hydration (from the tacky glue) to the solution. In conclusion, we can draw this results section to a close with a disproved, earlier stated hypothesis and that the thinner the polyvinyl acetate glue, the more flexible it is.

Results of Elmer’s Glue Lab: (Enclosed is the results of the Elmer’s Glue lab to be compared by the viewer. Previously stated comparisons are available to be read in the Results and Conclusion of Tacky Glue Lab section.) In order to document thorough results, it was vital to record the physical and chemical properties and reactions that occurred throughout the experiment. The first, and estimated to be seemingly one of the simplest, observations of the lab regards the minute details when stirring the solute (solid, in this case, the borax for the most part) into the solvent (liquid, in the case, the H2O and Borax solution for the most part). If the mixture is not blended, and a substantial wedge of borax laundry detergent is neglected at the bottom of the beaker, results may not be produced as they had been anticipated. This may be a consequential variable when dealing with later issues, such as skimming out 25 mL of the separated solute to commencing the chemical reaction of monomers linking to form the whole polymer. For best results, the two components of the mixture needs to be properly blended for 1-2 minutes of stirring, then again for about 30-60 seconds just moments previous to being added to the glue. After the proper quantity of stirring takes place, the solution will be saturated, not concentrated or diluted. If the solution is concentrated, then the borax would have to outweigh the amount of H2O in the beaker, and thus prevent the catalyzing proportions to coexist with the sticky adhesive in the alternative, yet smaller beaker. Nonetheless, a diluted solution would not culminate the correct response, either. An erroneous ratio of solid to liquid (solute to solvent) would severely modify the outcome of the experiment, because the end polymer would consist of too much liquid to hold any shape at all. On another note, the glue requires a bit of attention. Because it is in the glue’s nature to be viscous, it needs to be dually noted that its entails an opposite reactor (a solvent, in this case, the Borax solvent) to accurately activate the monomers, and ultimately form the long chain of of molecules in order to create the anatomy of a polymer. The following answers the “why” question in the situation. When the 5 mL of unembellished H2O is added to the resin, it just settles on the top as some sort of liquid film. And when the embellished water is annexed in the mix, with the help of the stirring rod, the reaction is catalyzed due to its chemical properties. The apparent physical attributes of the glue is altered into a swelled, glutinous adhesive with less viscosity than its genesis. In addition to this vital information, there are several other reactions that are significant enough to be mentioned. The glue fundamentally renders the following characteristics: coherent (as illustrated on the stirring rod due to its horizontal position and gravitational pull), slimy, mucilaginous, ill-fitted for reshaping, has similar qualities to liquified rubber with elasticity, and ultimately animated (with a vibrating reverberation) on contact. Any other qualities that remain while exposed to body heat via finger tips and palms include: H2O-infused, flexibility, and corpulent. The average rebound test yielded results of an average height of 7-13 cm. This evaluation was a good arbitrator when establishing the polymer’s physical and chemical properties due to its unbiased standpoint. To illustrate my point, visualize a room-temperature environment with a limited amount of variables in the atmosphere; it is the perfect locale for a controlled experiment such as this one, with no breeze or being to disturb it. After 10-15 of chilling in the refrigerator, the test was repeated about 3-4 more times with the same average height of 7-13 cm. However, this set of trials bore contrasting ramifications. Unlike the previous ball of water, glue, and Borax laundry detergent, this new gelatin-like sphere had a glossy off-white hue to it and held a shape about half the time that the original had been capable of. After the third trial with this new form, the body heat warmed the orb, and consequentially produced results with frequent similarities to the pioneering polymer.

Thursday, March 3, 2011

Sodium Silicate Polymer Lab Investigation

Problem: How do you make a sodium silicate polymer?

Hypothesis: When the ethyl alcohol is intermingled with the sodium silicate, the two will for a polymer via one providing the long chains, and the other providing as a cross-linker.

The main materials in this experiment were sodium silicate (approximately 20 mL) and 3 mL of ethyl alcohol. The procedures, in a round-about explanation, were equivalent to the following:

Measure 20 mL of sodium silicate with a gradual cylinder and pour it into the 200-250 mL beaker.

Quantify 3 mL of ethyl alcohol in a second beaker (one that had been empty prior to the alcohol and also holds the same quantities of 200-250 mL). This solvent was to be measured in the same gradual cylinder as the one used in advance. However, it is crucial to clean it out each time it is used, otherwise the mixture of solvents and solutes may cause a difference in chemical properties, thus disrupting the entire experiment. Note that alcohol is flammable, and needs to be handled with care, as does the sodium silicate.

At a steady pace, pour the alcohol into the beaker with the sodium silicate.

A stirring stick will be utilized in this next step. With a descent circular motion, stir the two solvents together to form a mixture that resembles tightly compacted snow.

With the forefinger and thumb on both the right and left hand, gently mold the solid mass into a sphere. To receive the best results, run the ball under flowing water for approximately 30 seconds while tightly shaping the polymer.

Use the Rebound and Temperature Test to calculate chemical and physical properties of the polymer, and use process of elimination to determine why this reaction occurred. Observe all worthy observations

Rebound and Temperature Test Procedures: The rebound and temperature test allows scientists in-the-making to chronicle the physical and chemical properties of a polymer. The only materials needed for these two tests are one 30 cm ruler, a flat surface such as a completely horizontal table, and a typical refrigerator (with temperatures at approximately 1.7 to 3.3 degrees Celsius or 35-38 degrees Fahrenheit). In order to test out the heated (more or less likely to be room temperature), vertically hold the ruler so that the 30 cm mark is at the top, and 1 cm mark is on the bottom. Mold the polymer in the shape of a ball for accurate and consistent ramifications. From the top of the ruler, drop the ball and observe how high and in which specific direction it bounced. Repeating this process several times is a recommended solution when trying to find a reliable average height; reform into a ball after each test if needed. Record conclusions, especially why this event occurred and what the exercise proved. To evaluate how a frigid environment affects the polymer’s chemical properties, place the polymer (still in the shape of a ball) in the center of a shelf (if possible), and wait for roughly 10-15 minutes. Once the substance has been able to settle in the refrigerator, re-alter the shape so that its mold is consistent, and eliminates any distorting variables. Reiterate the process used for heat. Record vital results.

Results and Conclusion from Sodium Silicate Polymer: From what was able to be seen from the naked eye, the solution of the ethyl alcohol and the sodium silicate has aroused several complicated, yet simple reactions. First off, when the ethyl alcohol was added to the silicate, already there were white specks, about half of a centimeter in length, that were forming on the surface of the liquids. It seemed as though the long (at least for the scientific branch of chemistry) chain were commencing their transformation, and preparing for the cross-linkers. This was when the chemical reaction was first recognized. Once stirring was initiated, there was roughly a 10-20 second delay before the two solvent morphed into one solute. This specific solute could be described as compact snow with a odorous fragrance of rubbing alcohol. In addition to this sense-stimulating expedition, concurring physical (caused by chemical reactions) features include having a moderate plastic texture, similar to the inside of a rubber bouncing ball, as well as a impressionable glossy sheen to its exterior. This glossy sheen is due to its extensive excursion in the classroom sink under cool to room temperature water, which being shaped into the proper mold (a sphere) for the rebound test. While Keara molded the newly made polymer in the sink, a foul odor emitted from the used water, and was hypothesized to be the residual components of the ethyl alcohol. This was the most reasonable explanation, considering that the alcohol was the cross-linker, and not all of the cross-linker is needed to be used depending on the amount of monomer chains formed from the silicate. There is, as there are for so many others in the scientific field, a logical axplication for these somewhat odd occurrences. The silicon atomic structure is simple and is only bonded to four oxygen atoms, disabling linkage in any specific areas. The ethyl atoms are even less complicated; they only contain two carbon atoms. Nevertheless, when the two are combined, with a little help from the stirring rod, the silicon branches out (with the side branches that mature polymers contain) to form the long chains, while the rivaling hydrous fluid enables interconnection because it acts as a cross-linker. These ethyl groups are additionally substituting for previous oxygen atoms.

Once this was accomplished, a ruler was utilized to estimate approximately how high the silicate ball could bounce due to its substance alteration (from where it would be dropped onto a flat surface such as a level table from 30 cm). After the first bounce, which was documented at a height of 10 cm, the ball crumbled and required repair. This repair included running it under water for about one minute, which consequentially was revived as a smaller, yet still usable orb. After this incident, no other crumblings took place. In fact, the orb was recorded to bounce at an average height of 8 cm, which correlated with its petit dimensions. One interesting fact that should be noted is that in two out of three trials, the ball bounced away; there were 3-4 trials for each rebound test, making it a total of 6-8.

On the other hand, fellow classmates chronicled contrasting results. For example, opposing classmate’s viewed an average height of 19.3 cm. This significant difference could have been the cause of extra water being added into my ethyl alcohol due to lack of drying the water from the graduated cylinder once cleaned in between uses. However, when my lab group and I placed the polymers in the refrigerator for about 15 minutes, it yielded an average height of 14 cm. This is a substantial difference than my classmates, who reached a height of 17.3 cm. However, there is a logical variable for this difference, as well. The quantity, as well as density and exact perimeter measurements have a huge impact on the gradient in which the ball hits the flat surface and bounces back up due to its energy levels. Because my ball was more cubic than others once frozen into an even glossier ice-like structure, it produced dissimilar ramifications.

Contrasting to the Borax laundry detergent and glue polymer made on Tuesday, the silicate polymer was more condensed. And as I am addressing Tuesday’s polymer lab, keep in mind the differing variables. The first polymer lab used white Elmer’s glue (or polyvinyl acetate), water, and Borax laundry detergent. This experiment bore the culminations of a more rubbery, sticky substance that did not keep its shape well, but could be impressionable. It was indeed, more like a combination of a liquid and a solid, whereas Thursday’s polymer was a definite “snow” or “ice” crystalized formation that either kept its shape or crumbled completely. The rebound temperature test generated an effect of 7-13 cm (dropped at the same height of 30 cm) at both room-temperature and cooled at 1.7- 3.3 degrees Celsius (35-38 degrees Fahrenheit). It’s undefined variables could have ranged from being a more viscous material, to its locale in the refrigerator (cool air sinks, and it was on a medium-level shelf), or even returned body-heat from constant reconstruction. Nonetheless, these two experiments differed more that they were similar. However, one variable was reiterated in both: the shape of the polymer once it was retrieved from the refrigerator, This shape-difference could have greatly effected the end product. That, and also the fact that a polymer is always a polymer, it is formed the same way, even though it uses different catalysts each time. No matter what, this stays constant.

At this point, you may be asking yourself, “well I know that there are carbon-based polymers that are in commercial plastics. What similar properties do these two chemicals have?” And if this is in fact true, I have, or at least Google has, the answer. According to several different experts, carbon-based polymers are the products, or gifts, of nature. Fundamentally, they are organic flexible molecular structures in plastic with denoting chemical bonds. While the carbon groups are authentic, the silicon-based polymers are synthetic, or man/woman’s gift to him or herself. This too, also has a pliable chain with strong, temperature-resistant bonds, which is why it is often profit-oriented.