SG/ Chem Blog FINAL

Over the last week and a half, we have done multiple things in sustainable green chemistry. The first this we did was a lab about heating curves, we also worked on formal lab reports on out PTVn labs about pressure temperature and volume. Then we learned about how to calculate the amount of energy used to raise the temperature of a substance by one degree Celsius.

Heating Curves:
In this experiment, we wanted to find how the temperature of water increased as we applied heat to it, what we found may surprise you. We found that as the water was heated, there were periods of time when the temperature would simply flat line, we realized that this was because the phase was changing.

*Example of a heating curve*

The temperature flat lined when changing phases because it takes a lot of energy to break molecules apart or to bring them together, so instead of raising the temperature all of the energy it being used in this case to go from ice to water, and from water to water vapor. To do this lab, we hooked a thermometer up to a mac and connected it to logger pro. Since Logger pro automatically plots the data, we only had to set up the table and then put the thermometer into a cup of ice water and turn on the heater.

Lab Report:

In class and at home, we have been working on formal lab reports for one of our biggest and most interesting labs. While I talked about the lab itself in a past blog I have not gotten a chance to write about the lab report. In the lab report I wrote about what I expected to see, what I did see and how the two compared. I also analyzed the data and thought of a couple scenarios that would have caused my data to be incorrect.

Calculating Energy:

 At first, I had trouble doing this, but then I realized that I was only having trouble because I was failing to do algebra. I spent a lot of time just racking my brain and I couldn't figure it out until I remembered all of the stuff I learned in algebra 1 ac. It also helped that my some classmates were understanding It so I could go to them for guidance.

Conclusion:

Over all, I had a great time this week and in all of SG/Chem. As the title said, this will be my last blog for a while and I have hoped you enjoyed it.

SG/Chem Blog 7

Over the last week we have done quite a few different things. One of the things we did was reviewing for the Unit 2 test on Monday. We also learned about PTVn tables, and began to prepare for writing a lab report about out PTVn labs.

Unit 2 Review:

To prepare for our unit 2 test, we created whiteboards that showed everything that we have learned.We did something very similar to this before our first test and I think that it was very effective.

*Examples of review boards*

During Unit 2, we learned about the relationships between pressure, temperature, volume,and the number of molecules. Pressure has a positive relationship with temperature, when the temperature increases, so does the pressure. This is because when gas increases in temperature, the molecules move at a faster speed and then hit the container more. Pressure has a negative relationship with volume, as the volume increases the pressure decrease, but the pressure will never reach zero. This is because pressure is created when molecules collide with the container they are inside, and no matter how large the container is, a particle will eventually collide with the outside creating pressure. Finally, pressure has a positive relationship with the number as particles, as the number of particles increases the amount of pressure increases. This is because as the amount of particles increases, more particles can collide with the container at a faster rate, therefore there is more pressure.

We also learned about the origins of Celsius and how it relates to Kelvin. Celsius was created by Anders Celsius, he filled a small vial with mercury and place the mercury in a pool of freezing water, he then took that measurement as 0 degrees Celsius. Then he place it in boiling water, he observed as the mercury expanded to fill up the vial, he then marked the top of the mercury as 100 degrees Celsius. That is the story of Celsius and also of the heat meter or, more commonly the thermometer.

We also learned about PTVn tables, they are simple tables that act as graphic organizers to help solve problems that use relationships between Pressure Temperature, Mass and Volume. I found these tables really useful. 

*an example of a PTVn table*

The table has the initial, and final values. It also shows how the changes effect the value you are trying to calculate. They help by providing a graphic organizer and visualizing causes and effects.

That is what we have done over the last week. I really enjoyed the last week of SG/Chem and feel like I learned lot.

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.

SG/Chem Blog 2

Over the last week in Sustainable Green Chemistry, we did lots of stuff. For most of the week we did lots of particle diagramming of experiments we did last week. We also learned about the problems that using different kinds of measuring tools can pose and significant figures.

Part 1: Particle Diagramming

Last week we did quite a few experiments with mass and change. To list a few, we took the mass of ice before and after it melted , and the mass of a sugar cube before it dissolved. If you want to read more about these experiments, check out last weeks blog post. This week we diagrammed what we think happened. We did this using particle diagrams.

*Unrelated particle diagram example*

While diagramming, we shared our data, we found that in most cases the mass changed very little or not at all. This is because of the Property of Conservation of Mass, this property causes the mass of an object to stay the same through any chemical reaction. The only experiment we did where this did not apply was when we burned steel wool. For some reason it gained mass, I think that it gained mass because of some reaction of the methane we were burning with the steel wool, or a reaction from the iron in the steel and the air, maybe forming iron oxide. I hope that Dr. Finnan will shed some light on this conundrum.

While doing particle diagramming, I found it interesting that sometimes everyone had very similar models but, other times the models were all very different. I think we had some very well educated discussions about our models in class.

Part 2: Significant figures and measurements

Significant figures are the digits that are important in a number, to find the significant figures, you follow a few simple rules, I will list them below:

1) ALL non-zero numbers (1,2,3,4,5,6,7,8,9) are ALWAYS significant.

2) ALL zeroes between non-zero numbers are ALWAYS significant.

3) ALL zeroes which are SIMULTANEOUSLY to the right of the decimal point AND at the end of the number are ALWAYS significant.

4) ALL zeroes which are to the left of a written decimal point are ALWAYS significant.

                              5)ALL exact counts (20 students) have INFINITE significant figures

Significant figures are important because they tell us how to round our numbers, they also help make our numbers more precise. Both of these reasons are very important for science because having accurate data is important. Another step towards having accurate data is having accurate measurements. For example, different scales will measure to a different level of accuracy (1g,1.0g,1.00g etc...). Also when taking measurements you only estimate 1/10 of the smallest marking on the tool.

Conclusion:

In conclusion, the last week has been very eventful in Sustainable Green Chemistry. We did lots of particle diagramming, and measuring. This week has made me really look forward to the next few weeks. 

See you next week! :)