SG/Chem Blog 6

This week my lab group did an experiment using a laptop computer, Logger Pro software, and a device plugged into the laptop. The experiment was about relationships between pressure and multiple factors.  Before we did the experiment we talked about pressure and how it works. We theorized that particles move faster when they are hotter and take up more space and create more pressure. Next we worked on experiments to demonstrate these ideas and prove what we theorized in our class discussion.  For the experiments we attached a plastic syringe to the device that was attached to the laptop so we could take pressure measurements.

The first experiment that we did varied volume to see what would happen to the pressure.  The Logger Pro software automatically recorded the measurements for us, so when we were done with all the different volume variations we could graph the results and look at the changes in pressure.  Before we did the experiment we expected that as volume increases pressure would go down. When we looked at the graph of our results we saw that they matched our expectations.  

For our second experiment, we varied the temperature to see what would happen to the pressure. The Logger Pro software again recorded the measurements at the different temperatures,  Before we did this experiment we expected that as temperature increased pressure would increase. When we looked at the graph of our results we again saw that they matched what we expected.

Finally, we created our own unit of measurement called "puffs" using the lines on the syringe as our guide.  We pulled the plunger out to different "puff" levels on the syringe and then pushed the plunger back in all the way and took a pressure reading each time. We expected that this would demonstrate that as the "puff" level increased the pressure would increase because more particles make the pressure go up.   We looked at the graph of the measurements and found that they matched our expectations.  

These results made sense because of what we learned in class about how volume, temperature, "puffs", and pressure are related.

 

SG/Chem Blog 5

Over the last week in sustainable green chemistry I will be honest, we didn't do that much. For the first half of the week, we were very busy with our unit one exam and the PSAT. In the second half of the week we started unit two, unit two is focused on energy and movement of molecules.

Part 1: Testing

On Monday we spent the day reviewing everything that we have learned. This included histograms, significant figures, and how to read graphs to name a few.

*The board we made with everything we have learned*

To do our review, each table filled out a whiteboard with everything that we did. We then compared whiteboards and presented then to the class, I think that this form of review was very successful because it made us think of everything and then if we didn't remember something we were able to see what it was, and how it relates to the other stuff we learned. My groups whiteboard had everything it needed and I think my table and class did a good job overall on the unit one exam.

Part 2: Energy and molecules 

To start off our second unit we began studying the movement of molecules and how the movement is affected by energy.

The first experiment we did showed that heat energy affects the speed that particles move. To do this, we had a glass of hot water and a glass of cold water. We used a dropper to place green food coloring into both glasses. We then watched the dye spread through the cups, we found that the due spread faster through the hot water than the cold water. This leads us to believe that the heat energy increases the speed at which particles move. After we did the experiment, we created whiteboards of what we believed happened. Every groups model showed the spread of dye in a slightly different way.

On Friday, we watched a series of videos called Eureka, the videos explained the movement of molecules (Latin for "Little Lumps") as a dance where the particles are attracted be repulsed. The videos also talked about how liquids turn into gasses at high temperatures. Liquids do this because as the temperature increases, so does the speed at which the particles move, the speed increases until they break free of their bonds with the other molecules. The same process also happens when going from solids to liquids.

Part 3: Conclusion

This week, we were really busy but, we didn't get a lot of science done. I hope we get to get a lot more done next week. What we did learn is very important and will help us understand the rest of unit two.

What we learned:

-particles move faster when they have more heat energy

-molecules move at all times

SG/Chem blog 4

To all Over the last week in sustainable green chemistry, we continued our studies of mass density and volume. We also did a lab about the density of gas. 

Part 1: density, mass, and volume 

To continue our studies, we worked with our groups on a couple of worksheets. These worksheets gave examples of different ways to solve for mass or volume. One way we were shown, was to multiply the given variable by the equation for the density of the material (g/mL). If we were given a value that was of mass, the equation for density would be flipped, for example:

    g x mL / g =___   or   mL x g/ML =___

We used these equations to help solve a few word problems. My favorite word problem was about a woman whose cheapskate boyfriend got her a ring and said it was 24 carat gold, the question asked us to determine if the ring was real, or if she should dump her dewdbeat boyfriend. In the end, their relationships ended tragically. 

Overall, I really enjoyed this part of our week. It was a lot of fun and I feel like I learned a lot.

Part 2: Density of gas?

This week we did a lab that addressed the question of "how dense is gas?"

Our lab setup included a bin filled with water, a small jar with a tube attached to the top and a bottle filled with water in the bin. The tube from the jar went into the bottom of the bottle. To create the gas to measure, we had alka seltzer tablets .

                    *the experiment*

To answer this question, we first had to find the mass and the volume of the gas. To find the mass, we measured the mass of the jar filled with 40mL of water and the alka seltzer. Then we measured the mass of the jar after the alka seltzer dissolved and found the difference. The difference was the mass of the gas that escaped when the alka seltzer dissolved. To find the volume, we let the gas flow through the tube and into the bottle, once inside, the gas began to displace the water that willed the bottle. We then looked at how much water had been displaced. 

With our volume and mass calculated, we only had one more step. The last step was to calculate the density  (g/mL), we found that the density was around 0.002 (g/mL). That means that gas is around 500 times less dense  than water.

I enjoyed this lab, it was very interesting to learn about how dense gas is. I think it is also important to learn how to calculate the density of gas.

Part 3: Conclusion

Overall, it was a good week in SG/Chem. I had lots of fun and I think that I learned a few new things. The things that I learned include:

- New ways the solve for mass/volume, and how to use that knowledge in word problems

- the density of gas, and how to find the density of gas

SG/Chem Blog 3

Over the last week in Sustainable Green Chemistry, we focused on Density, Mass, and volume. We started by doing POGILs (Process Oriented Guided Inquiry Learning) to learn basic concepts. After that we moved onto labs to learn about density mass and volume hands on. That's the short version, now let's jump straight into some chemistry.

Part 1: POGIL

To start our week off, we did 3 POGILS. Now, you might be asking yourself," What are POGILS?". POGILS are worksheets that teach by asking questions and providing a process to help you find the answer and teach yourself. I think that POGILS are great ways to learn, because it pushes students in the direction of being their own teacher. It helps people learn problem solving skills, and I think that it helps me remember the information, so I am prepared to do the labs.

*POGIL map*

The POGILS that we worked on mostly focused on data analysis, and understanding the relationships among mass, density, and volume. They did this by asking questions about the relationships between mass density and volume that we worked together in our groups to answer and learn.

Later in the week we did a lab that demonstrated these proprieties. Specifically we measured the mass and volume of steel, aluminium, and acrylic.

Part 2: Density, Mass, and Volume

To learn about density, mass, and volume we completed a lab to learn through experimentation.

Activity 1: Cubic Centimeters Vs. milliliters  

The first thing we did was establish the relationship between cubic centimeters and milliliters. To do this we made measurements of the width and length of an acrylic box, we then filled it with water up to a random point and measured the height of the water. Then we multiplied length by width to find the base, and we then multiplied the base times height to find out how many cubic centimeters of water there were. Finally we transferred the water into a graduated cylinder and measured the exact volume of the water. We then repeated the same process five times so that we would have multiple data points. In the end we discovered that one cubic centimeter is equal to one milliliter.

Activity 2: Density Study

The second activity was a study about density. We had rods of equal size made of steel, acrylic, and aluminium. We first measured the weight in grams of these rods and found that without exception the steel rods were the heaviest and the acrylic rods were the lightest with the aluminum rods falling somewhere in between. The next thing we did was fill a graduated cylinder with water. We then measured how much water was inside the cylinder. After we had taken a measurement, we placed one of the rods into the water and looked at how much water was displaced. The amount of water displaced was equal to the volume of the rod. While we didn't calculate the density, this experiment showed that density is related to the Mass of an object because, if an object is denser, it has more mass even if it has the same volume as another object.

Part 3: Conclusion

This week I learned:

• How density, mass and volume are related.
• How to test relationships between measurements of volume by looking at the relationship between 1 cubic centimeter and 1 milliliter.