Wednesday, September 29

Today, Mr. H started off the class by telling us to wipe down the lab tables with a wet paper towel after a chemical lab. He said that we should do that every time we work with chemicals in order to have safety precautions. After that, we admired Natasha's blog that she did the night before. He reminded us that there is the site called DropShots and it is where all of the pictures go from a lab or a demo that day. If you are the scribe, then you can use it to get some pictures.

He then told us to get our lab notebooks out. We were to do Mendeleev for a Day Lab (AMI4) and the Oleic Acid Lab (AMI3). He summarized what we were supposed to do while we wrote down the purposes of the labs.

He told us to find a partner, or if we preferred, work alone to do this lab. Mendeleev for a Day is a lab that required the sheet that was given to us yesterday. It had 20 squares and we were supposed to cut them out for class. Each square had the Atomic Mass, the melting point (degrees C), the boiling point (degrees C), the number of O in oxide, and the number of Cl in chloride. Those were two chemical properties of the element and also two physical properties. We were to start putting the squares in order from least to greatest according to the atomic mass in a row. From there, you were to look for common points, and to move them into columns. More specifically, the number of O in oxide and the number of Cl in chloride. These columns are called families. Mr. H gave an example of his own family. Mr. H's father had a specific way of walking. If you look at him and then Mr. H, you wouldn't see a difference. He also gave us an example of the males in his family get gray hairs around their 30's. He told us this because it relates to the lab. Families have similarities and in the periodic table, the columns have similar properties, putting them in the same "family." Anyways, after we put them in columns, we taped them into the Data section in our lab notebooks. Remember to put the squares on the paper landscaped. This provides more room for the squares. Or, you could put it across two pages in your lab notebook like this (left):


The Oleic Acid Lab is much different. We were working with lycopodium powder. Lycopodium powder is made out of a type of moss, and can trigger some allergic reactions, if you are allergic. Oleic acid does not mix with water, but dissolves the lycopodium powder. The first thing we did was put our safety goggles on. At our lab stations, there was already a yellow tray with water. We were to gently put the lycopodium powder on the surface of the water until it looked a little filmy. Mr. H did a little demonstration on how to do it:
This is how it looked like (bottom):

Then, when we were ready, Mr. H came around each lab group to put a drop of oleic acid into the tray. What we observed was that the oleic acid dissolved in the lycopodium powder, but in the process, it spread out on top of the water. It had a large diameter. This is what the oleic
acid looked like after Mr. H put it in the tray. As you can see from the picture, it dissolved the lycopodium powder and made the water easier to see through. There is no more of that filmy look.

Mr. H gave us a sheet of paper to record our data in, and the number of drops/mL of .500% oleic acid solution is 32. We decided that the average diameter of the drop was 14.8 cm. You are to find the surface area, height, length, width, volume, and mass. For homework, we are to finish the data sheet and the conclusion/discussion for both labs. See you tomorrow!