Oct. 22-26

In chemistry this week, I learned about expansion, contraction, and the relationship between pressure, volume, temperature, and the number of particles.

On Monday, I was reviewing with my class the ethanol and water experiment–both were heated on a machine over a certain amount of time and given energy through the process of heating–and why the ethanol in the tube rose while the water didn't. The answer is expansion. Expansion is when a liquid takes up more volume as its volume is increased by more energy input through heating. Therefore, expansion occurred in the ethanol while heating occurred. The heating caused the particles to spread out over a longer distance, therefore, causing the ethanol level to increase.


Throughout the week, we learned the opposite of expansion–contraction. Contraction is where the volume of a liquid is going down as a result of it cooling down. As the liquid cools down, the particles get closer and closer together. They don't spread out. Therefore, the volume goes down as the particles become more densely packed from cooling.

The connection between expansion and contraction is how they affect the overall density as well as volume of a liquid. Through expansion, the volume increases, meaning that the density is going to decrease since the number of particles and mass remain the same with increasing volume. As for contraction, the volume increases. Therefore, the density will increase since the number of particles and mass remain unchanged with a decreasing volume. Therefore, expansion and
contraction affect not only the volume
of a liquid, but also its density.


Yet, the heat could have caused the water to evaporate and perhaps the ethanol. However, both tubes had stoppers, thus preventing anything from entering or leaving the system. But, the question is: What prevented the liquid from coming out the tube? Well, I speculated that gravity and the attraction (suction) between molecules could have collided the air particles with the water particles. But, what really prevented the water from coming out the tube was pressure–as a pushing force between the air particles and the water particles. Pressure is the physical force exerted from one object onto another object, which can be represented by the formula: pressure=force/given area. In this case, the air particles exerted their physical force onto the water particles.

Pressure, though, is affected based on the force exerted onto the area, which means that the greater the area or volume, the less the pressure. If the area were less, though, then the pressure would be greater. Pressure is affected because the greater the area is, the greater the resistance to apply pressure is. Therefore, the pressure is less than if there were a lesser area that pressure would exert with less resistance.


Throughout the week, the focus was on pressure, volume, temperature, and the number of particles, which were utilized in four experiments including: volume vs. temperature, pressure vs. volume, number of particles vs. pressure, and the number of puffs vs. pressure.

The relationship between volume and temperature was a direct one. The greater the temperature was, the greater the volume. The reason for this is because the greater the temperature, the greater the energy input through the process of heating. This would cause the particles in a liquid to separate farther from each other, thus increasing the volume.

In this class, there were four experiments. My group and I did puffs vs. volume. During the experiment, we used 2 puffs for every mL. So, the data was this:

1/4 puff=228 k/Pa
1/2 puff=220 k/Pa
1 puff=116.14 k/Pa
3/2 puffs=69 k/Pa
2 puffs=63 k/Pa

Therefore, the relationship between Pa (pressure units) and volume is that the greater the number of puffs, the less the pressure. These findings make sense because the volume and pressure are inversely related. Therefore, the more the volume is, the less the pressure is.

Like the puffs lab, the pressure and volume were inversely related to one and another. The greater the volume is, the less the pressure is. This is so because the mass and
the number of particles
remain the same, so if
the volume increases,
then the pressure would
decrease.

The relationship between temperature and pressure is that since increasing temperature would increase the volume, then the pressure would decrease. Therefore, the more the temperature is, the less the pressure is.

The relationship between the number of particles and pressure was direct. Thus, the greater the number of particles is, the greater the pressure is.

However, temperature doesn't influence the number of particles and vice versa because temperature doesn't determine the number of particles. Nor does the number of particles determines the temperature.

Oct. 15-19

This week, we learned about the motion of particles in solids, liquids, and gases, how energy and heat affect the motion of particles, and the different motions of particles.

First, I learned about the different motions of particles. The three types are: translational motion, rotational motion, and vibrational motion. Translational motion is the motion of particles moving side to side. For example, particles in a solid move side to side. Rotational motion is the motion of particles moving from one point around and back to its initial point. For example, when liquid particles are heated, they move rotationally. Vibrational motion is the motion of particles moving through particles.
For example, heat causes gas particles to move.

This week, I learned about sublimation. Sublimation is the process of matter turning from a solid to a gas, thus skipping the step of turning into a liquid. Mr. Abud demonstrated to us the dry, for instance. It turned from solid dry ice to dry ice with steam coming out. So, my group and drew particle diagrams showing before and after its conversions using the movements of particles. Before, the particles moved left and right. But, after it turned into gas, the movements went in all different directions since gases can spread from one place to another.

I learned, therefore, that particles in solids do move, thus challenging the previous belief that the particles in a solid did not move. Essentially, they move back and forth, left to right. Mr. Abud showed us a cartoon showing particles moving in this fashion as they danced. The connection is that in all solids, particles do move.

Next, I also learned that solids are rigid, meaning that they hold their own form and shape, since the molecules are attracted to each other. Therefore, they have no fluidity, meaning that the particles don't flow and move.

On the other hand, liquids and gases have fluidity. A liquid cannot hold its own shape except when it holds the shape of the container it's in. Otherwise, liquids flow because the motion of particles is faster, and they go in different directions; yet, they are also repulsed and held together. However, as the liquid flows, the distance increases. But, gases move faster than liquids and move greater distances.

The motion of the particles in these three states of matter vary because of how heat affects the motion of these particles. Heat is a form of thermal energy–it is just another form of energy transfered through heating. It is the same thing as energy, except energy is stored. Heat makes the particles move faster, therefore making a substance more less viscous, meaning that the particles become less resistant to move. The more heat the substances, the more energy they are receiving to put the particles in motion. For example, hot fudge that is melted is less viscous than hot fudge that hasn't been melted. The melted hot fudge will flow at a quicker rate since the heat enables the motion of particles to take place at a greater rate and distance. However, the unmelted hot fudge will have a slower motion of particles, meaning that it will move at a lesser distance at this rate. Therefore, if solid, liquid, and gas particles are heated, then the particles move faster with greater energy at greater distances at this rate with greater energy.

Also, what affects the motion of particles is temperature. Temperature is the measurement of the average amount of energy for all particles in a system. This means that the greater the temperature, the greater the amount of heat and energy. Therefore, a greater temperature gives more heat and energy for the particles in any state of matter to move faster. Temperature doesn't directly affect fluidity and viscosity–heat and energy do. But, temperature is like a gateway for heat and energy to affect
these factors.

The connection between these three states of matter (solid, liquid, and gas) is that since the motion of their particles vary, their densities vary also. For example, since a solid is rigid and the particles stay closer together in a lattice work pattern while still in motion, they have the greatest density since the space between the particles is less than that of liquids and gases. Liquids, though, have lesser densities than solids, but densities greater than gases. Since the motion of the particles in a liquid are quicker and the particles move in different directions, the space between them is greater, therefore, the density is lesser. Gases have the least density because the space between their particles is the greatest since the particles can move faster than the particles of a solid and liquid.

Oct. 8-12 Reflection

Primarily, the main ideas this week were about finding the density of an actual human being, reviewing over density, mass, volume, and particle diagrams, and using the scientific method.

This week, we reviewed over how particles should be aligned. Even though we did not come to a consensus as to how they should look, the two options that they were in a straight line or like stacked fruit in a grocery store where there would be space between the particles on top and bottom.

First example, Jack and Maria volunteered for the experiment. The question was what their densities were, so we hypothesized that Jack would have a greater density than Maria.

By calculating their densities, we were essentially increasing our knowledge on how to find density, mass, and volume. In this experiment, we used the scientific method to make this experiment function perfectly. In the scientific method, the question is always asking about the answer.

The hypothesis, though, leads to how the experiment will be done because it sets up as an educated guess that will be challenged. The procedure, though, is the biggest how because this includes the steps to the experiment, in what order they will be performed, and how they will be performed.

So, after making the hypothesis, we planned our experiment out before we did the experiment. The first thing we did was to collect their weights in pounds so that we could convert them to grams later for their masses. For example, Maria’s weight was 91.8 pounds, and Jack’s weight was 151 pounds. Then, we had to determine how we were going to get their volumes using water displacement.

But, first, we had to convert their weights in pounds to grams. Jack's mass is 68,490 grams, and Maria's mass is 41,639.78 grams.

The idea to find volume was to place the kiddy pool underneath the garbage can. Then, fill a garbage can with 44 gallons of water, since that was the maximum it could hold, and that the displaced water, as a result of the two students getting in at different times, would pour out of the garbage can into the pool. Then, we would collect the amount of water using 2-liter bottles, and that would be the volume. After we did this, we had to count how many 2-liter bottles were filled for both Jack and Maria so that we could find their volumes.

 

Then we had to convert the liters into mL keeping in mind that 1 liter=1,000mL. Jack’s volume was equal to 54 liters, so in mL, his volume was 54,000 mL, and Maria’s volume was equal to 39 liters, so in mL, her volume was 39,000 mL.

Next, we divided the newly converted mass by the newly converted volume. So we found their densities to be:

Jack=68,490g/54,000mL=1.2012666 g/mL.

Maria=41,639.78g/39,000mL=1.067g/mL.

Some of the important details to consider were that to find the mass of a human, you must weigh them first in pounds and then convert their weight to grams. Next, the volume had to found through water displacement–in this case, it was the difference between the 44 gallons and the new amount of water with a person in the water. The difference was the amount of water that poured in the kiddy pool. Then, as soon as those were found, the density could be found. Also, it was important to know how to do the experiment. Otherwise, you would be lost in the process of finding the answer to the hypothesis, and then the process of the experiment would be disorderly.

In class, we discussed what we would do before we did the experiment. Someone suggested that a kiddy pool should be used, and someone suggested that a garbage can should be used, but first, we had to determine that someone could fit in the garbage can, and they did. Also, we had to determine that the pool was large enough to hold the water, and its dimensions were 5 by 7 feet, so this would be enough. To plan out the experiment, some of the students, including me, went on Google Drive and wrote down the procedures to the experiment.

During the lab, I helped my class collect the water in 2-liter bottles in order to collect Jack and Maria's volumes. The water we collected was the water that was spilled into the kiddy pool, which was underneath the garbage can. Then, what I did was add suggestions to some of the slides, such as the sources of uncertainty slide. I suggested that they should have added the fact that some of the water poured all over the floors, so the volume was measured less than it should have. Thereby, the densities should have been less.

Reflection Week: Week 1

On the first week of school, I learned about the fundamentals of chemistry, such as the process is more important than the answer, it is important to form a consensus, and to not worry about grades and to know everything.

On the first day of school, I learned that the process is more important than the answer. Even though an answer is important in order to know something, the process is really important because if you only know the answer and not the process, then you can't explain how you got it. So, I realized that a correct process helps get to the correct answer.

During this week, I participated in two interesting games both involving a consensus.

For example, I played the cube game where we all had to guess what the bottom face was. My group and I guessed it was 20 because we were noticing the tape on some of the faces, and we saw two of them on the #5, #4, and #1. Ee multiplied these numbers by two and added them together to get 20. Most of the class, however, said 6 because some of them thought of the cube as a dice, or some of them thought that it was logical. Others said 0 because it came before 1, 2, 3, 4, and 5, or one group suggested that it could have been nothing.

Next, we had to come to a consensus, and we agreed that it was, most logically, 6.

But, we found out that there wasn't a face at all. The cube was really a box. I realize it now because I noticed a black line on the bottom of the box, indicating that it was a box because the inside was not exposed to any light.

In a class activity during this week, I participated in an activity, which consisted of 32 cards, and that in eight groups with four students each, you have to meet up with people based on a grouping of these cards in categories.

In this activity, I learned about a consensus, which is an agreement that everyone makes based on their conclusions of their experiments and whether or not they think their data is correct, and the golden rule is that everyone has to agree.

Of course, there was some conflict. For example, many people argued about the placement of Mars in the candy group and believed it should have placed in the planets group, and whether Mercury should have been placed with cars or planets. However, everyone eventually agreed with the organization and categorization of these objects.

During this week, I learned about the basic purposes of Lino and Evernote in the computer lab. Lino is a site where you can post notes, and you can connect with ChemT3am to post notes during class so that everyone can see them during class discussions and lab experiments, and Evernote is a site where you can schedule the dates of your tests and the dates to take reassessments. But, I also learned that these sites are important in this class so that I can use them to learn about chemistry with technology "at the tips of my fingers."

In the computer lab, we also learned that we could use Google Drive to exchange class documents and perhaps homework assignments. Also, I learned that day that I could just use Google Chrome instead of the outdated Internet Explorer, so I am very glad, and I use Google Chrome whenever I am in the computer lab.

Also, we learned about TwitterProject180, which is used to post tweets on Twitter involving reflections on class discussions and lab experiments. Additionally, I noticed that this could be used to predict what might be on the assessments. These discussions on Twitter, in my opinion, are used to discuss many things that we have learned, so that we can be more prepared, and it makes learning unique and exciting.

Lastly but most importantly, I have learned that in this class, grades don't matter. I realized that it matters if you really learned it. A grade only indicates, as my dad once said to me, how well you take tests. But, how well you master the criteria is really important in helping you succeed in this class.

Based on what I have learned this week, the connections and ideas I can make are that in life and in this class during the year, a consensus has to be made in order to solve a problem without conflict, and everyone has to agree. I learned that technology can be connected to my education, and I learned that I could use these sites in order to participate in class and after school.

Reflection Week Oct. 1-5

As of this week, I learned how to calculate the thickness of aluminum using only a ruler and a balance triple beam scale, how to calculate the volume of candy, and how to measure the volume and density of a gas.

On Tuesday, we measured the mass, volume, and density of Starbursts. However, my group and I had to use, to measure the volume, water displacement, which is that any object immersed in water will rise through if the water density is greater than the material density. So, the first step was to unwrap the Starbursts and put them in water, then take them out and measure the new volume of the water, and then find the difference of the old volume of water and the new volume of water, which would be the volume of the candy. Then, find the volume, which is the new volume of water, and then divide the mass of each of the Starbursts by their volumes to find their densities.

The orange Starbursts had a mass of 4.8 grams, a volume of 4 mL, and a density of 1.2 g/mL. The yellow Starbursts had a mass to be 5.3 grams, the volume to be 5 mL, and the density to be 1.06 g/mL. Then, the mass, volume, and density of the red Starbursts were 5 grams, 4 mL. and 0.8 g/mL.

On Wednesday, we found the thickness of aluminum to be about 0.0013 cm. The density was 2.7 g/cm^3, and using the balance scale, the mass is 2.5 grams.

To find the aluminum's volume, length and width were measured with a ruler. The length is 30 cm, and the width is 23.5 cm, which were multiplied to equal 705 cm^2. However, height (thickness) was excluded. So, d=m/v was used to calculate volume.

Steps:

1. 2.7=2.5/v
2. 2.7v=2.5
3. v=2.5/2.7
4. v=0.93 cm^3
5. v=l*w*h
6. v=(30)(23.5)(h)
7. v=705h
8. m/v=d
9. 2.5/(30)(23.5)(h)=2.7
10. 2.5/705h=2.7
11. 2.5=1903.5h
12. h=0.0013 cm

On Thursday, we learned how to use equipment to find the volume of a gas. To do this, my group and I filled the trough with water. Next, we filled two cups with water. Then, we hooked up the flask, containing the water and the alka seltzer, on the balance scale, with a nozzle where the gas would travel through it, as a result of the chemical reaction between the alka seltzer and the water creating a gas.

Initially, though, we measured the mass of the beaker and the water at 193.7 grams and the volume of the water at 295 mL.

With the cups of water, we put them, one at a time, in the trough upside down in the trough. But, the challenge was to avoid spilling them, so we used a lid for each of them, and as soon as the cups were in the trough, the lid was carefully removed.


We then observed the fizzing of the alka seltzer and noticed in one of the cups in the trough that the water level was going down and increasing the water level of the trough. Knowing that the volumes of the bottles were 295 mL, we then calculated the volume of the gas, which was 260 mL, meaning that 35 mL added to the water level of the trough. Then, the mass of the beaker was calculated at 192.7 grams, which was 1 gram less than what it was before the gas entered into the bottle in the trough. Then, the density was calculated at 0.0052 grams/mL.

Lastly, we discussed three theories, which are that densities: vary because of particle size, space between particles, and greater mass if substances being compared were to have the same volumes. Therefore, these theories may explain why a solid has the greatest density, a liquid has the second greatest density, and a liquid has the least density. Discussing these three states of matter, we found the densities on average, which were 4.19 g/mL for a solid, 1 g/mL for a liquid, and 0.0045 g/mL for a gas.

The connections between these experiments are that mass, volume, and density is extremely important ways to measure matter, space, and matter within an amount of space. Another important factor is that to find either one, use the density formula, which essentially, is one of the best mathematical principles in science.

By getting involved in these labs, I understand that different methods of measuring volume don't end at the tick mark on a ruler. The candy lab demonstrates that volume can be found using water displacement, and the volume of a gas could be found using complex equipment.