Intro to Energy

The main ideas we learned this past week were what happens when we heat ice to boiling, how to do LOL problems, and what the bubbles in boiling water are made of. These concepts go together and connect because they all involve energy. Some important details of the main ideas were the states of matter: solid, liquid, and gas. Some other important details were melting, freezing, evaporating, and condensing.

The Icy Hot Lab-
In the Icy Hot Lab the goal was to see what would happen when we heated ice cubes to boiling. We also wanted to find out at what exact temperature did the phases start to change. We had the idea that ice would start melting at about 0 degrees C and start boiling at 100 degrees C. The first step in the lab was to attach a temperature probe into the Logger Pro interface. Logger pro is a graphing software program that collected and graphed our data for us. Then Dr. Finnan came around with a cooler filled with ice and put a scoop of ice in each of our beakers. The beakers were sitting on a hot plate that was turned onto the hottest setting. We had to start swishing the probe back and forth in the ice in order to get an accurate reading. Once the temperature was no longer dropping we pressed start experiment on Logger Pro and it immediately started collecting data. We recorded in our journals the temperature when the ice started melting, all the ice had melted, and when the water had started to boil. The temperature when the ice started melting was -4.7 degrees C. The temperature when the ice completely melted was 14.4 degrees C. The temperature when the water began to boil was 97 degrees C. After the water has begun to boil you wait until the temperature has stabilized and then you end the experiment. When we looked at our graph we noticed that it flat lined during phase changes like melting and evaporating. We white boarded our findings and a particle diagram of the particles in different times during the experiment.

Another group's white board representation
and particle diagram

LOL Charts-
We use LOL Charts to find out what happens when something evaporates or to find the energy flow. We call the LOL chart an LOL chart because there is a graph on both sides and a circle in the middle and that literally looks like you spelled out LOL. To find the energy flow you have to first plug in the initial temperature and initial phase. Then, you fill out the final temperature and final phase. Then you add up your initial numbers and your final numbers. Lastly, you subtract final minus initial.

An example of an LOL chart

Bubbles in Boiling Water- 
As you probably already know, when you boil water bubbles start to form. And you probably already know that when water boils its turning into a gas and evaporates, but you probably didn't know that the little bubbles in water when its boiling are actually made of water vapor even though most people think the bubbles are made of air.

Reflection-
We came to know and understand the concepts of this week by doing experiments and work sheets. I still have questions about why we subtract final minus initial when doing LOL tables. My participation in the learning process in class this week was good. I would rate myself an 9 out of 10 on the ideas I talked about today. I could still work at little more on LOL tables because it has been a while since we did them and it would be nice to have a review. My ideas have changed because now I know that water doesn't boil and melt at exactly 100 and 0 degrees C.

Test Review and PVTn Tabels

     The main ideas we learned this week were how to answer pressure, volume, temperature, and number of particles word problems using PVTn tables. And, we reviewed all the things we did in Unit 2 for our exam. These relate because PVTn tables are going to be on the test, and PVTn tables help us practice how pressure, volume, temperature, and number of particles connect with each other for the test. One important detail is when doing a table you have to convert all Celsius temperatures into Kelvin. The reason we do that is because we can't measure gas with the Celsius scale because it doesn't use absolute zero as its 0 degrees. To practice for the test we made a white board representation of all the activities we did in Unit 2. We did several worksheets to practice PVTn tables.

PVTn tables-
We used these tables to answer problems that start by giving you P,V,T or n and we had to find the solution. In order to find the solution we had to determine how changing P,V,T, or n will affect our starting quantity. When doing this we kept in mind how P,V,T, n relate to each other and if their relationship is direct or inverse. Also we kept in mind to always change Celsius to Kelvin. To do that you have to add your temperature in Celsius to 273 Kelvin. Then we took the number we wanted to find out and multiplied it by the appropriate factor. To decide the appropriate factor you look at the up or down arrows in the affect box. The variables should cancel themselves out, and you should end up with the right one.

Example of a PVTn table

Test Review-

We made a white board representation to help practice for the test. On the white board we put the many experiments and activities we did. The first thing was a representation of the popcorn experiment. The popcorn experiment was an experiment that tried to prove that gas particles moved. Dr. Finnan opened a bag of popcorn in the corner of the room and we had to raise our hand when we smelled it. Another experiment was the dye experiment where we put dye in hot and cold water to see which moved faster. We also did the hotness meter where we essentially made our own thermometer and tested it in hot and cold water. We watched three videos about solids liquids and gasses and how there particles move. We blew a student up by having her sit on a bag and blowing air in the sides through straws, and lastly we popped a balloon and a popcorn bag by reducing the pressure on the outside.  

Our board

   We came to know and understand what we did this week through doing worksheets and doing white board activities. I sill have questions about why gas can't be measured in Celsius. I think my participation has been good this week. I would rate myself an 9 out of ten on the concepts we learned this week, so I don't need to work on anything in particular. My ideas have changed because now I know the material better.