Today we tested the conservation of mass. We took pop rocks, soda, vinegar, and baking soda. We took a 20 oz bottle of Dr. Pepper and one pack of pop rocks to test the reaction. We took a balloon and and funnel and pour the pop rocks into the balloon. Then we tried to create a reaction with the pop rocks and the soda. We place the balloon over the top of the bottle to see if we could trap the gas that it created to fill the balloon. Our attempt was not a success because the balloon was not tightly around the top so most of the gas escaped and the balloon did not fill like it was supposed to. We tried again by pour more pop rocks and a different balloon, but then the balloon broke. So we tried to get another balloon on there fast. That balloon still did not fill that big, but bigger than the first attempt. The next test we conducted was with the vinegar and the baking soda. This was more of a scientific “cliche” but we still conducted it because we knew that it would create a gas that would fill the balloon. This experiment worked a lot better. I think it was because we had out the balloon on better from learning from the first test. I also think that it worked better because it created more gas and there was more of a reaction. In the first test, the gas was already there but we just released it. In the second test, we created gas rather than it already being there.
Thursday, March 17, 2011
Tuesday, March 15, 2011
Chemical Reactions and Temperature Lab Investigation
In this experiment, we tested chemical reactions in different temperatures. We tested what change in the chemical reaction would happen if we changed the temperature of the water. At first, we tested the water at room temperature. The water started out at a temperature of 74.8 degrees F. We put the tablet of alka seltzer in and the bubbles started to form. The chemical reaction was that the tablet created bubbles that fizzed up to the surface of the water. The reaction lasted about 36 seconds. During that time, the degrees of the water decreased about 0.7 degrees. The next test that we conducted was water that had been cooled with ice cubes. We had stirred the water for about a minute to make the water equally cool. Once we stirred the water, we did that same as the last experiment. We tested the chemical reaction again with the alka seltzer tablet. This time, the reaction was different because the water was colder. The alka seltzer tablet was dissolving a lot slower than the first tablet. The reaction time was 1:06. I think that the coldness of the water slower down the reaction. The water was 58.5 degrees F before and after the water was 58.6. The last experiment was conducted with hot water that was heated up to 52 degrees C, which is 125.6 degrees F. This time, the tablet dissolved a lot quicker than the room temperature and the cold water. The tablet dissolved in 21 seconds. I think since the water was heated up, it caused the water to speed the reaction.
Friday, March 11, 2011
ChemThink Questions
C H E M I C A L R E A C T I O NS T U T O R I A L Q U EST I O NS :
1. Starting materials in a chemical reaction are called reactants.
2. The ending materials in a chemical reaction are called product.
3. The arrow indicates a chemical change.
4. All reactions have one thing in common: there is a rearrangement of chemical bonds.
5. Chemical reactions always involve old bonds.
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. 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 as 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
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 + 2 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 2 atoms.
16. When we added a molecule of CuO, now the number of Reactant atoms is balanced but the number of Product atoms don’t match. Now we have to add more reactant atoms to the reactants.
17. The balanced equation for this reaction is
2 Cu + 2 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
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 KClO3 = 2 KCl + 3 O2
21. What is the balanced equation for this reaction? (Use the table to keep track of the atoms on each side.)
4 Al + 3 O2 = 2 Al2O3
SU M M A R Y
1) Chemical reactions always involve old bonds.
2) The Law of Conservation of Mass says that the same atoms must be present before and after the reaction.
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.
1. Starting materials in a chemical reaction are called reactants.
2. The ending materials in a chemical reaction are called product.
3. The arrow indicates a chemical change.
4. All reactions have one thing in common: there is a rearrangement of chemical bonds.
5. Chemical reactions always involve old bonds.
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. 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 as 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
# of atoms in Reactants | Elements | # of atoms in Products |
4 | H | 4 |
2 | O | 2 |
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 + 2 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 2 atoms.
16. When we added a molecule of CuO, now the number of Reactant atoms is balanced but the number of Product atoms don’t match. Now we have to add more reactant atoms to the reactants.
17. The balanced equation for this reaction is
2 Cu + 2 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 | Elements | # 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
# of atoms in Reactants | Elements | # of atoms in Products |
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 KCl + 3 O2
# of atoms in Reactants | Elements | # of atoms in Products |
1 | K | 1 |
1 | Cl | 1 |
3 | O | 2 |
21. What is the balanced equation for this reaction? (Use the table to keep track of the atoms on each side.)
4 Al + 3 O2 = 2 Al2O3
# of atoms in Reactants | Elements | # of atoms in Products |
1 | Al | 2 |
2 | O | 3 |
SU M M A R Y
1) Chemical reactions always involve old bonds.
2) The Law of Conservation of Mass says that the same atoms must be present before and after the reaction.
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
Today we retested the experiment of the glue polymer. We were told to redo an old polymer experiment, or look up another one to do. Our group chose to redo the glue polymer lab, but with a little modification. We had decided to add double the amount of borax solution. So instead of adding 5 mL of the borax solution to the 40 mL of glue, we added 10 mL. When we started to stir the glue, there was a lot of extra borax solution. We had concluded that the glue was fully saturated and could not hold anymore of the borax solution. I had suggested that because of the extra moisture, the ball would bounce higher. We had started to conduct the experiment and we started off the same way as before, but then we added the 10mL of the borax solution. Because we had added double the amount of borax solution, there were some differences in the outcome of the experiment. Some of those were that the ball was a lot more sticky and stretchier than the first time. I think that a chemical reaction in the glue had caused the glue to become more sticky with more moisture. When we were waiting for the piece that we put in the fridge, we had started to mess around with the polymer left in the jar. When the ball had warmed up to room temperature, it bounced higher and was not as sticky. The borax solution was also cold, so we concluded that because the borax solution was cold, that is why at first, when we first took out the polymer, it did not bounce. When we took it out of the fridge, it was a little more bouncy, but still not enough to measure because it was sticky. When it was room temperature, it lost a lot of its stick. So, it bounced higher when it was warmer because there wasn’t as much stickiness.
Thursday, March 3, 2011
Sodium Silicate Polymer Lab Investigation
In this experiment, we were making another polymer ball composed of ethyl alcohol and sodium silicate solution. We also had preciously created a ball made of glue and a borax solution made of 2 teaspoons of borax and water. It created a chemical reaction and created a solid out of the glue. There also were some similarities between the two balls though. They were both made from polymers. They also but were caused from a chemical reaction that occurred between a liquid and a thicker liquid. Some differences between the balls were that the ball made from the alcohol and the sodium silicate solution was more crystallized than the other glue ball because we had to form the crystallized ball rather than the glue ball which was more like a solid to start. In the experiment that we did today, our group had created the biggest ball in the class. I do not know if was our measurements, or if it was that our ball just created easier, or if it was the way that we were rolling our ball. I do not know, but if it was any of those then it is possible that anybody could have possibly made one just as big as ours. You could tell that there was a chemical reaction occurring because when you started to stir, crystals started to form at the bottom of the beaker, and it was getting harder to stir. It was getting harder to stir because it was forming into a solid. It was the same with the first experiment. Once you added the solution into the glue and stirred, the glue started to become a solid and it got harder and harder to stir. When you were trying to roll the ball, there was a liquid that kept coming out of the ball. You could tell that the liquid was the alcohol because of the smell. Once you lost that liquid from rolling the ball, it would crumble. That is the reason that you needed to put it under the water, so there was enough moisture in the ball to keep its shape.
Since we had created to ball with each of the polymers, we had a rebound test and compared the two tests. The first ball that we made, the one made of glue, bounced about 16-17 cm. The other one, the one made of sodium solution and alcohol, bounced about 15-16 cm. I think that the rebound of the second ball rebounded lower than the first ball because the second ball was a little more densely packed and not as flexible. The glue ball on the other hand was flexible and more bouncy therefore it went higher than the crystallized ball.
Since we had created to ball with each of the polymers, we had a rebound test and compared the two tests. The first ball that we made, the one made of glue, bounced about 16-17 cm. The other one, the one made of sodium solution and alcohol, bounced about 15-16 cm. I think that the rebound of the second ball rebounded lower than the first ball because the second ball was a little more densely packed and not as flexible. The glue ball on the other hand was flexible and more bouncy therefore it went higher than the crystallized ball.
Monday, February 28, 2011
The Science of Addiction
Natural Reward Pathways Exist In The Brain
There are several distinct regions in the brain. There are some regions in which pleasure and reward are associated with certain parts of the brain. The job for the reward pathway is to make us feel good such as activities like eating, drinking, and sex. The chemical dopamine is released when the brain is notified that you have eaten and you are full. This dopamine gives you a sense of pleasure. That is your reward for eating. The reward pathway is linked to the memory part of your brain, and the behavior part of your brain. The memory region helps you remember that you liked the food that you ate and you would like the eat it again. The behavior part of the brain helps you repeat that behavior such as remembering to eat something you like. The reward pathway helps us remember the behaviors for survival.
Drugs Alter The Brain Pathways
There are many different drugs of abuse. Too much alcohol causes loss of motor skills, balance, speech reaction time, and judgement. Large amounts of alcohol causes nausea, vomiting, loss of consciousness, and possible death. Anabolic steroids are man-made substances that are similar to male sex hormones. Although some bodybuilders and athletes may abuse the drug because the promote muscle growth. Steroids may be a drug worth using but there are some side effects. It may increase risk of heart attack, strokes, liver problems, and it also might cause loss of hair, and acne. Next is heroine. Heroine is the most used opiate. Heroine causes a rush of pleasure then you crash. These are just some of the many drugs of abuse out there.
There are several distinct regions in the brain. There are some regions in which pleasure and reward are associated with certain parts of the brain. The job for the reward pathway is to make us feel good such as activities like eating, drinking, and sex. The chemical dopamine is released when the brain is notified that you have eaten and you are full. This dopamine gives you a sense of pleasure. That is your reward for eating. The reward pathway is linked to the memory part of your brain, and the behavior part of your brain. The memory region helps you remember that you liked the food that you ate and you would like the eat it again. The behavior part of the brain helps you repeat that behavior such as remembering to eat something you like. The reward pathway helps us remember the behaviors for survival.
Drugs Alter The Brain Pathways
There are many different drugs of abuse. Too much alcohol causes loss of motor skills, balance, speech reaction time, and judgement. Large amounts of alcohol causes nausea, vomiting, loss of consciousness, and possible death. Anabolic steroids are man-made substances that are similar to male sex hormones. Although some bodybuilders and athletes may abuse the drug because the promote muscle growth. Steroids may be a drug worth using but there are some side effects. It may increase risk of heart attack, strokes, liver problems, and it also might cause loss of hair, and acne. Next is heroine. Heroine is the most used opiate. Heroine causes a rush of pleasure then you crash. These are just some of the many drugs of abuse out there.
Wednesday, January 19, 2011
Chemistry Video
When they combined equal volumes of equal gases, it produces twice the amount of gas. Gases were made of multiple atoms called molecules. Organic substances were different than non-organic substances. When a scientist combined two non-organic chemicals, he created one organic crystalized chemical. The periodic table of elements was created by Dmitri Mendeleev. Bunsen and Kirchhoff used the spectroscope to discover two more elements known as Cesium and Rubidium. Plastic are polymers. Polymers are long chains of molecules. They can be molded into different shapes. They are strong and they can be made into many things.
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