Conservation of Mass Investigation

Hypothesis: The baking soda and vinegar will create more mass than the soda and pop rocks because while the soda and pop rocks are just releasing the carbon dioxide trapped in them while an actual chemical reaction is going on with the baking soda and vinegar.

Observations: For the first part of the experiment with the pop rocks and the soda the balloon did not get blown up much at all. The reason for that was the balloon was being blown up by only the amount of Carbon Dioxide that was in the spark rocks instead of some kind of chemical reaction. (we know that it was Carbon Dioxide because the packet it came in said so.) What was kind of interesting was that our balloon did not inflate as much as some other groups. This may be because of the difference between the spark rocks and how much carbon dioxide they had in them.

The next experiment with the baking soda and the vinegar released much more gas and filled up the balloon quite a bit. By the time the balloon stopped inflating it was about the size of a cantaloupe. There was a lot of bubbles made by the chemical reaction, and when we measured the vinegar after the chemical reaction we found that the amount appeared to have increased. But we figured that it was just because of the amount of bubbles in the cylinder.

The picture above is what the two experiments looked like next to each other.

Conclusion: I excepted my hypothesis because the baking soda/vinegar combination worked much better and released more gas than the soda/pop rock combination. In this lab it was much harder to form a hypothesis. Jacob, Rory, and I had to gather a lot of information and make a bunch of inferences to come up with a decent hypothesis. All in all, it was a great experience and taught us a lot about the subject of mass. And the only problems that came up was a defective balloon for the second experiment. Luckily it did not ruin the results.

Chemistry Reaction By Heat Lab Investigation

Question: Does temperature effect chemical reactions?

Hypothesis: Yes, the higher temperature the faster the reaction. (this is for this experiment, it does not necessarily apply to all of them.)

Results: When we put the alka-seltzer in 266mL of hot water, it immediately fizzed up. Stirring was not even necessary. The top was covered in bubbles and the reaction went on for 21 seconds. The tablet was raised to the top by the bubbles and quickly dissolved into the water. The hot water was exactly 50.8 at the time we put the tablet in.

The room temperature water took longer to dissolve the tablet. There were also less bubbles than before while the reaction took place. The bubbles kept on appearing for at least 34 seconds. The water was 24.5 degrees(in other words room temperature).

For the cold water experiment we only used 133 mL of water unlike the other tests because we had to add ice to this one. The reaction lasted for 2 minutes. Not only were there hardly any bubbles for this one but unlike the last two times the tablet stayed at the bottom of the beaker. The temperature of the water was about -.1 degrees.

Conclusion: My team excepted our hypothesis because, after reviewing the notes, we came to the conclusion that the temperature was what made the experiment's results different. When the water was hot the tablet dissolved very fast. When the water was cold it dissolved very slowly, almost adding a minute and a half to the original time. This was the first time we got to work with heat(i.e. heating stuff up, etc.) and it taught us to be very careful with lab equipment. In real life, not only do some experiments have dangerous chemicals in them but they also may have some stuff where you can badly burn your fingers. The only problems we may have had was not burning our selves, we did have some close calls. That, and the fact that for the cold experiment I, instead of getting 133 mL, accidentally got 266 mL like the other two experiments. Luckily Miss. Leland stopped us before doing the experiment but we learned we have to be much more diligent in the future.

ChemThink; Chemical Reations

Note: My answers are in red.


1. Starting materials in a chemical reaction are called: starting points.

2. The ending materials in a chemical reaction are called: ending points.
3. The arrow indicates a: chemical change has taken place.

4. All reactions have one thing in common: there is a: rearrangement of 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 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. If we use only the atoms shown, we’d have 2 atoms of H and 1 atoms of O as reactants. This would make 1 molecule of H2O, but we'd have 1 atom of O leftover. However, this reaction only makes H2O.


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: 4 H reactants with 4 atoms of them in the product. 2 O reactants with 2 of them in the product.

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

12. There must be the same type 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 this equation, we have to add 2 molecules to the products, because this reaction doesn’t make lone O atoms.

16. When we added a molecule of CuO, now the number of O 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

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 + 1 O2 --> 1 H2O + 1 CO2

# of atoms in Reactants Element # of atoms in Products
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

20. What is the balanced equation for this reaction? (Use the table to keep track of the atoms on each side.)

2 KCIO3 --> 2 KCI + 3 O2

21. What is the balanced equation for this reaction? (Use the table to keep track of the atoms on each side.)

4 AI + 3 O2 --> 2 AI2O3

SU M M A R Y

Chemical reactions always involve: breaking bonds, making bonds, or both.

The Law of Conservation of Mass says that the same atoms must be: There must be the same amount of present before and after the reaction.

coefficients; atoms

Note: I had to remake my blog and this post got deleted. I just noticed this yesterday, so thats why this is posted so late.

The first great discovery of chemistry was in the later part of the 1800 century was made by Preistly. This had to do with gases. Preistly went to Paris to talk with another great chemist.

List of elements made by Preistly.

Second discovery was made by John Dalton, which was the first person that "discovered" atoms. He made a new system called the Atomic Theory.

Turn of 1900th century. Davey discovered how electricity reacted to different chemicals and change them.

Bunson and Kurkofe built a spectroscope where they could see what atoms were present. They were able to discover two more elements. They ended up using their machine to discover that their was sodium in the sun.

Joseph Thompson discovered electrum. He used a crook’s tube in his expiriments to study small parts of atoms.

The discovery of how atoms of one element combined with atoms of another element was discovered by Gilbert Newton Lewis. This led to scientists starting to make chemical compounds.

X-rays were the start of this discovery. Over the decades, scientists started making break throughs.

Bekrel discovered that uranium emitted x-rays by using the photo paper. The Curies then took up the project and in the process, discovered two new elements in the process.

John Hyatt made the first plastic, and led the discovery of different plastics.

Nanotubes where discovered by Richard Smallway and a team of scientists. Nanotubes are a cluster of carbon atoms.

Polymer Lab Group Investigation

Title: Polymer Lab;Changing Variables

Problem: How can we make a stronger polymer using materials similar to the ones used in Tuesdays lab? (glue and two tsp. of borax)

Hypothesis: If we use a stronger type of glue, and more borax, then the solution that we create will be stronger, and it will have a higher rebound factor.

Changes From First Experiment: Instead of white elmer's glue we are going to use wood glue. Also, we are going to conduct two separate experiments. The first one we will only change the type of glue. The second one, however, we will also include a increase of 2tsp. for borax. The reason for this is too see what will be the cause of certain changes, the wood glue or the increase in borax.

Materials:

Elmer's wood glue

water

stirring rod

500mL beaker

250mL beaker

graduated cylinder

borax

Results: The first experiment(we used wood glue instead of regular) was a success, we ended up creating a stronger polymer that did not come apart as easily. In fact, this one had lots of differences from last Tuesdays experiment. For one, it was yellow because of the wood glue we used instead of Elmer's white glue. Another thing was that is was much more soft, sticky, and it was easier to mold even when it had been in the freezer for 10 minutes. It was also very stretchy. We were able to stretch it up to 14 feet after we had freezed it! But even after it had gotten out of the freezer it wasn't very solid, even molding to the shape of the beaker it was in. As for the rebound measure it was much less than Tuesday's, the average being about 4.4, and after the freezing it was about 9.

While the first experiment went fairly well, the second experiment had much different results. This time the result was messy, while the outer parts was very hard, the middle of the glob was still liquid. In the end, it was too sticky to even take it off of the paper towel.

Conclusion: I partly except my hypothesis. While we did make a stronger polymer than before, the rebound was drastically less. Instead of the 10cm. before, the wood glue polymer made it only about 4.2. But I do believe that my whole group was surprised by the outcome. I was skeptical whether or not using wood glue would make a different to the outcome, or if it would even work. But if anything, it worked even better than the white glue. But the second experiment didn't turn out too well. The result was a yellow, gooey sticky mess, instead of the stronger, more bouncy polymer we were aiming for. The huge problem we had in our lab was not being able to even get the second experiment's results of the paper towel we put it one so we couldn't see the rebound factor. But it was such a large mess that I don't think it would have even mattered. But what was really exciting about this investigation was that my group got to make their own experiment like actual scientists. We got to research different things and see what we could change about the experiment to get different results. And while one part of the experiment was a success, the second one was a failure. While it was a bit disappointing, it was interesting to learn what the effects of more borax was. It was really a real life experience.

Sodium Silicate Polymer Lab Investigation

Problem: What does a sodium silicate polymer look like?
Hypothesis: It will be much like the experiment before. It will be a rubbery, squishy, and solid mass.

Results/Observations: At first, my lab group thought that the two labs would wield similar results. But the differences between the two labs became apparent not too far into the investigation. When we combined the sodium silicate and ethyl alcohol it just looked like very cloudy water. But when we started stirring it, we saw imediat changes. It looked all crinkly on the top, and as we kept stirring, it become a crystallized pile. (look below)
We poured the crumbly mixture onto Rory's hand and she squeezed it all together to form a ball, occasionally adding water. The ending result was a hard, condensed white ball. (look below)
In the end, while it was still a polymer, this investigation resulted in something much different than before. Not only were they made differently with different ingredients, but the first was rubbery and squishy, the second result was hard, dense, and reminded us of a bouncy ball. Also, the second result was much more bouncy than the first, having an average of 21 cm when room temperature, and an average of 18.25 cm after it had been in the refridgerator for 10 minutes. The first expirement only bounced up 9 cm and 15 cm when it was cold.

Questions
What characteristics are similar between your two types of polymers you have made? Differences?
Some similarities would be the fact that they are both white, moldible, and bouncy. But the second polymer was much more bouncy and a lot harder to mold. In addition, the second one was made much faster.

Most commercial polymers are carbon based. What similar properties to silicon and carbon share that may contribute to their abilities to polymerize?
They can bond very easily because they can give or take 4 electrons.

Plastics are made of organic (carbon based) polymers. What similarity does the silicone polymer share with the plastics?
They can both bond easily.

How did you know that a chemical reaction had taken place when the two liquids where mixed?
When we put the two liquids together it immediately became cloudy and when we started stirring it it became crinkled at the top and changed consistency.

How could you find out what liquid was pressed out of the mass of crumbled solid as you formed the ball?
You could smell it to see if it smelled like the ethyl alcohol(alcohol has a very strong smell that can burn your nose), or if you had the equipment, you could use different chemicals to see whether or not it was the alcohol or not.



Conclusion: I rejected my hypothesis because it was way off. My group thought that since we were making a polymer, the result would be similar to the one we had for the first experiment. Instead, it was almost the opposite! Instead of the soft, putty like result we have for the first experiment, we got an extremely bouncy, hard, slightly crumbly, semi-translucent ball. The only problems that we had was over/under measuring the sodium silicate. This experiment can be aplied to real life because this was really the first time I have ever worked with dangerous chemicals. While the sodium silicate just made your skin burn, it was very good practice for the future. Also, we got to learn more about polymers and how they differ.