Week 11 Reflection

During chemistry class this past week, the class split up into pairs and each small group was to make a thermos. Throughout the planning stages, my partner and I ran into the dilemma on what to use to insulate our cup. One of my suggestions was that we use a chemical heat pack that I possessed and wrap it around the cup to heal seal the energy in. Our problem was that this pack radiates energy when the coin on the inside of it was snapped to cause the mixture on the inside to crystallize and give off energy; it is not like your standard heating pack/source, for it creates its own energy instead of recieving it from an external source, such as an outlet. After discussing this with Mr. Abud, he suggested that we make two thermoses: one with the chemical heat pack wrapped around it and the other made the standard, acceptable materials. Our first thermos, the chemical heat pack, was fairly simple to assemble and recquired few materials. In order to build this thermos, we surrounded a styrofoam cup with the chemical heat pack and used electrical tape to secure it into place. As for our second thermos, its design was a bit more complex than the other. When building this thermos, we constructed it by taking a cardboard box and cutting out holes in a thick roll of foam that were made to fit the styrofoam cup. After placing the cup in the middle of the holes, we used a hot glue gun to glue styrofoam packaging peanuts and adhesive stryofoam to the cup to further insulate it. From there, we sealed off the top of the cup using more hot glue to stick a thin cardboard slab covered in adhesive foam over the opening.

From then on, we were able to test out both of our thermos by adding 350 mL of boiling water to our cups and recording its temperature every minute. Each measurement was taken in degrees Celsius, but had to be converted to degrees Kalvin for this experiment. Once both trials of each thermos had been recorded, my partner and I were able to compare the results of each of the thermos to help us come to the conclusion on which thermos more effectively retained energy. Much to our surprise, the thermos with the styrofoam cup surrounded by foam chunks had done a better job of retaining energy that the one with the chemical heat pack around it. We had assumed that since there was a small amount of heat being added to the system, that would've helped the cup keep the water hotter for longer. Its failure to outshine the other thermos was most likely due to the fact that the chemical heat pack thermos was not sealed off very well, therefore allowing energy to escape out of the system. Another thing we ran into along the course of the experiment was that the water was never at the temperature we hoped for when it was poured into the styrofoam cups. It was always a few degrees cooler, slightly throwing off our data planning and making it a bit more difficult to record data for this experiment.

Week 10 Reflection

During chemistry class this week, one of our main discussions was if it was possible to change the temperature without changing the state of matter. We are able to deem this true by increasing the particle movement and the particle spacing too. Other measurable factors that could potentially have an affect on the movement of particles were temperature, volume, viscocity, and mass. From there, we conducted the "hotness" lab, where there was a flask full of 500mL of ice water and a smaller flask with 10mL of water at 50 degrees Celsius and then another flask with 100mL of water at 25 degrees Celsius. The flask with 10mL of hot water was then poured into the flask of ice water, before having the temperature recorded. The same was done for the flask with 100mL of warm water, only it was poured into a seperate flask of 500mL of ice water. When comparing the temperature measurements from both flasks, it was clear that the warm water had more of an affect on the ice water than the cold water did. As both of the waters were poured into the ice water, energy was being added into that system. Energy can be associated with the motion/speed of particles, for temperature doesn't depend on how many particles there are, but rather how fast they move. This then brought up the discussion of what really is energy...

When discussing energy, we were able to list various different kinds of it: kinetic potential, thermal, chemical, nuclear, solar, hydro, wind, etc. But when it came down to defining it, the explanation was simple: energy is energy is energy! It was like talking about Baskin Robbins; while there are 35 different flavors of ice cream, in the end, it's all just ice cream. Energy has the ability to be stored and transferred, but one cannot simply "get rid of energy". An example to help further explain this that of an iPod, and how its music be e-mailed, burned from a CD, or bought on iTunes without these transfers changing the state of the song. Energy also can be viewed as a substance-like quantity that has the ability to be stored in a physical system. It also is able to "flow" or be "transferred" from one system to another, which can cause changes, but still maintains its identity after being transferred. However, energy is NOT the same thing as heat; if you mix the two up, you owe the class a dollar!

Week 9 Reflection

In chemistry class this week, one of the main components we reviewed involved the relations of volume, pressure, and the temperature of a gas. The volume of a gas is directly related to the temperature of a gas, meaning that if the volume is increased by 2 units, so does the temperature and vice versa. The pressure of a gas is inversely related to its volume; this means that if the volume is multiplied by 2, the pressure is multiplied by 1/2, the inverse of two and vice versa. This was extremely helpful, especially when completing PTVn charts. PTVn are story problems based on chemistry that consist of at least two the components above (pressure, temperature, volume, and number of particles). The relations reviewed above played a huge roll in solving these problems, for they helped limit certain areas with their rulings.

Also, another idea explored this week in class was the barometer. A barometer is tool used in chemistry to measure the atmospheric pressure. Our assignment was to make a barometer outside of school with a partner for class. My partner and I made sure to utilize various materials, such as a glass jar, a ballon, a straw, tape, a rubber band, and water. Our first step was to fill the glass jar up halfway up with water. After, we were to cut the balloon in half and stretch the half without the neck over the top of the jar, before sealing it with a rubber band. The straw was then taped down on top of the balloon, in the center. Then, we drew marks on a piece of paper showing where the straw originally started, along with other tick marks to show where the straw could potentially move to as the atmospheric pressure changes throughout the day and was placed behind the jar. If the pressure increased, you could tell by physically looking at the balloon; as the pressure increases, it exerts a downward force on the ballooon, causing the top of the balloon to become concave and straw to point upwards. If the atmospheric pressure decreases, you can also see this through a physical change in the balloon; since the pressure decreases, the balloon is now slightly convex and the straw is pointing downawards. In lower pressure systems, the temperature is generally warmer and the air is usually containing more moisture, while higher pressure systems usually consist of cooler temperature and less humidity and moisture in the air. This was demonstrated after the class took their barometers outside to test and everyone's straw was pointing upwards within 15 minutes, ultimately proving this to be true. This is the same for those of us here on Earth, because after all, "We are the Spongebobs under this ocean of air."

Week 8 Reflection

During chemistry class this past week, we continued our discussion of pressure vs. the changing factors of a system. In a direct pressure vs. particles system, doubling the number of particles always doubles the pressure because the have a constant ratio. Pressure is equal to the number of particles multiplied by a pressure to particle ratio. In a directly proportinal pressure vs. temperature relationship, it was odd to see the beginning of the line of the graph not start at zero, which aroused the question, do particles still move at 0 kilopascals? Though particles are still moving at 0 degrees Celsius, is there still a temperature that all particles stop moving at? It was then revealed to us that after many tests and multiple researches done on this topic, that there was an "absolute zero". This "absolute zero" is -273.15 degrees Celsius or 0 Kelvin.

This week, we were introduced to the concept of a third temperature scale: Kelvin (whose units are the Kelvin). From here, we were able to determine that while Celsius is relative to water, Kelvin is the absolute scale. When dealing with Kelvin from now on, it was agreed upon that instead of starting our graphs at zero, we would start our graphs at absolute zero, or -273.15 degrees Celsius. We then established rules for converting tempertures after noticing certain patterns in our data: degrees Celsius ---> Kelvin = degrees Celsius + 273.15; Kelvin ---> degrees Celsius = Kelvin - 273.15; degrees Celsius ---> degrees Fahrenheit = 2(degrees Celsius) + 32.

Another discussion in class involved two full 2 L bottles of water each with a tube with on a rubber stopper on top. One tube has a sealed tip, while the other's tip was unsealed. As you squeezed the sides of both bottles, you could see the pressure building up inside the bottle as it forced water up the tubes, causing them both to sink. The only difference between the two was that sealed tip tube didn't stay sunk and bounced back up. While each tubes mass stayed the same, the volume increased inside the sealed tip tube, causing it to bounce back up after hitting the bottom of the bottle becauses it was less dense. The unsealed tip tube stayed at the bottom of the bottle because its volume had decreased, which then caused its density to increase and not allow it to float.

Week 7 Reflection

In chemistry class this past week, we did a mini experiment involving water and ethanol in test tubes. One test tube had a designated amount of water in it while the other had ma atching amount of ethanol. Both had stoppers sealing off the top of them with narrow, straw-like tubes coming out of them. Each of the test tubes were placed in a flask of water over a heating plate. The heating plate was thne turned on and each of the liquids began to rise. As time went on, it became noticeable that the ethanol was rising more rapidly than the water was. We were then able to determine that as the liquid's volume increased, it's density decreased, which also caused the ethanol to rise faster than the water, for it was less dense. Since temperature is the measure of the energy (motion/speed) of the particles, we could then relate the speed of particles to the surrounding temperature. The average velocity of these particles all depended on the temperature, for particles do not move as rapidly at colder temperatures.

Another new idea that we were introduced to this week was the idea of pressure. Pressure is an inverse relationship of force over an object's surface area. For a steady force, the surface area must decrease in order for the pressure to increase; with a steady surface area, the amount of force must increase in order for the pressure to increase. We then came to the consensus that some of the factors that might affect gas pressure would be the number of particles, the volume of the gas, and the temperature. From there, we conducted an experiment to help us understand the relationship of pressure vs. the number of particles. We were to take a syringe and attach it to a Labquest, which would calculate how many kilopascals were being exerted throughout the experiment. A happy medium was established: 10 milliliters, which was where the pressure would be measured after each number of puffs. Each puff consisted of 4 milliliters of air and after each puff, the end of the syringe would be drawn to 10 mL to measure how the pressure was affected by more and more particles being added and taken away from the system. We then came to the conclusion that after each puff, the amount of pressure at 10 mL nearly doubled.

One of the other pressure experiments we did this week consisted of measuring pressure to see how it varied at designated mark. We first had to hook a syringe up to a Labquest's pressure sensor to help us obtain an accurate reading. If the syringe was pulled, the pressure would decrease, but if the syringe was pulled in, the pressure would increase. After obtaining our data, we noticed our graph looked a little more different than usual because it had a negative curve to it. In order for us to graph a linear function, we were informed that are volume measurements were to be inversed. This would help us equate the two things because they were now both consistently proportionate. By multiplying the temperature to the inverse of the calculated volume, we were able to obtain a more familiar graph, for pressure is inveresely relateed to volume at a constant temperature.

Week 6 Reflection

During chemistry class this week, we were introduced to the main idea of particles and what affects its motion. As a class, we agreed to represent the movement of particles by drawing arrows or more formally known as "whooshies". While reviewing the movement of particles in solids, no matter how "solid" an object is, we were able to determine that there are always particles in motion even if they don't appear to be moving. Between each of the molecules are small consistent attractions and repulsions that cause the molecules to continue this pattern. Most molecules in solids are in a lattice pattern to prevent the solid from potentially falling apart. Of the three states of matter, solids are the most dense and are the coldest as well.

Upon the reviewing of the molecular makeup of a liquid, the attraction and repulsion cycle is broken and the molecules are now floating freely and randomly. Liquids seek the lowest possible level of Earth and do not have a designated molecular structure; they simply take the shape of the container they are in. The particles in liquids are more active than those in solids, but are less active than those in a gas. A liquid's temperature is warmer than a solid's and is also less dense. As for gases, they are the warmest and least dense of the three states of matter. Gases have no molecular structure and have far more molecular range of motion than solids and liquids. Of the three states of matter, gas particles move most easily about compared to that of liquids and solids.

Other concepts we were introduced to this past week involved fluidity, rigidity, and viscosity. The concept of fluidity only applies to gases and liquids and is defined as the flow ability for particles. As an example, think of a cup of hot tea. A cup of tea with lemon juice in it is more fluid than a cup of tea with honey due to the fact that lemon juice isn't as thick as honey and has a thinner consistency. However, gases are far more fluid than liquids. This then ties into the idea of viscosity, the resistance to flow. As for the lemon juice and honey example, this would then mean that the glass of tea with honey is more viscous than the tea with the lemon juice. Liquids are more viscous, but less fluid than gases. As for rigidity, it is defined as the rigidness or stiffness of an object that only applies to solids.

Week 5 Reflection

While in chemistry class this week, one of our first topics of discussion related back to a previous experiment involving measuring the thickness of aluminum foil. The question asked was, "If regular aluminum foil is 0.0014 cm thick, how does the arrangement of heavy-duty particles (0.0022 cm) compare to those of the regualar?" If aluminum foil was one particle layer thick, that would then mean that the heavy-duty foil would be 1.5 particles thick. Unfortunately, you cannot have half a particle, as this theory was quickly shut down. Another thought was that maybe the particles were staggered, but that then revealed the fact that there would be empty and open spaces in the material. Then, the first idea was brought up again, but with a twist: it wasn't in its lowest whole number ratio. By multilpying each number by two, we were finally able to achieve an answer of a 2 particle layer: 3 particle layer ratio that everyone agreed upon. Through this consensus, we were able to establish the fact that you may have to manipulate the numbers to make them cope with reality.

Mr. Abud then introduced our latest experiment to us: we would be measuring the density of a student. In order to prepare for this, we needed a plan to help guide us through the process. As a group, everyone began to share their ideas with each other and how we were going to make this work. We eventually were able to settle upon using Thomas Goffas and Shannon McEnroe as our test subjects. The plan was to use the emergency shower to help us fill a 44-gallon trash can that was inside a kiddy pool. The shower head itself had a plastic shower curtain wrapped around it to prevent water from splashing out as the can was slowly filled. From there, we would have one of the testers slowly climb their way into the can so the water was able to displace into the kiddy pool surrounding it. We were then able to have people take empty jars, 2 liter pop bottles, and milk jugs to fish out spilled water out of the pool for further measurements. For those who didn't have 2 liter bottles, they were able to use a funnel to help pour water from other containers into the 2 liter bottles, for the shared a common measurement link the "grams for every milliliter" units we were using. After this, we recorded each person's mass and then coverted the mass from pounds to grams while also converting the calculated volume from liters to millilters. From this point, we were then able to use the gathered data on each students calculated volume and shared mass to help us fully conclude with what the density of a human was. Our final conclusion was that a person's density is solely dependent on their mass and volume. Those with more mass than volume will have a higher density than those with more volume than mass.