Lab 2B: Candium

The purpose of this lab was to apply the knowledge of isotopes, atomic masses, and how to find the average mass in a situation. We were given 3 different types of M&M's (which were supposed to be 3 different isotopes of new element candium), and then, step by step, applied the knowledge that we learned in the morning in a real-world environment.

My partner and I found that the average atomic mass was 1.49 amu.

1. A different group got that the average atomic mass of candium was 1.413. The reason for the difference would probably be different percentages of different isotopes. For example, the other group may have had a larger percentage of peanut M&M's than my group. Since the proportions aren't supposed to be the exact same across the board, a variance was expected.

2. If all of the groups that participated in this lab were given an entire backpack full of candium, any differences that the groups had would be smaller than they were with the sample size we were given (about a beaker full of candium). The reason for this would be because a larger sample size is more indicative of the population as a whole, so the proportions would be very close to each other.

3. If I were to place a piece of candium on a scale and weigh it, I would not expect the exact average atomic mass to come up on the scale. The reason for that is because the mass is an average of 123 pieces of candium. And since the average of a set of data isn't the same as a mode of a set of data, I wouldn't expect any piece of candium to weigh exactly the same as the average atomic mass.

4.

Lab 2A: Chromatography

(Fig. 1, my favorite paper chromatogram produced during this lab)

1. It is important that the wick and not the paper circle touches the water. The reason why this is important is because chromatography is a method of examining different components of a mixture when the components are too similar to observe without separation. So, because you have to be able to observe these different components, putting the circle straight into the water will likely result in not all of the components in the ink being visible.

2. Some of the things that affect the pattern of the colors on the paper are the brand of marker, the ink used, and the components in the ink.

3. Each ink separates into different segments because they are made with some different components. For example, with the larger ray of color on the chromatogram, the ink was black. However, there were also secondary components of the ink. So, these secondary colors are able to be seen through this method of chromatography, resulting in different colored pigment bands.

4. In all of the chromatograms that the class made, I noticed that there were a lot of light blue shadings on most of them. Since we only used black markers, the compound of the components was always the same, even though they were made by different companies. Despite the fact that we used different branded markers, it's likely that the companies used some of the same components when making their markers, so as a result, any same component in different markers will result in the same color showing up when doing chromatography.

5. Water soluble markers were used in this exercise because when they come into contact with the water, they show their components (via colors), whereas permanent markers wouldn't be able to work using water because they aren't water soluble. If one wanted to see the components that make up a permanent marker, a solvent that wasn't water would have to be used.

Lab 1B: Aluminum Foil Lab

Introduction: The purpose of this lab was to find out how thick any piece of aluminum foil would be when given a piece of aluminum foil and some solid aluminum formed in a single shape. It also served another purpose, which was how to apply the formulas we had learned, and use them to find out other values.

Procedure: To start out, my partner and I had to find out the density of aluminum so we could apply it to the piece of aluminum foil. In order to do that, we needed to find the mass and volume of the aluminum we had. In order to find the mass, we just weighed it on a scale and got a mass of 14.95 grams, and for the volume, we used the water displacement method. The water displacement method is where you fill a cylinder up to wherever you want (just not to the absolute top), drop the thing that you're trying to find the volume of into the water, and subtract the original water volume from the water volume with the object in it. Using this method, we were able to get a volume of 5.4 milliliters. And as 14.95/5.4=2.8, the density of the aluminum is 2.8 g/cm^3. Using the density, we were then able to find the thickness of the aluminum foil. To delve deeper, we developed a formula based on the results we grabbed earlier. Since we were able to find two (non-thickness) related dimensions of the aluminum foil, which were 11.11cm and 12.00cm, and the mass of the sheet of aluminum foil, which was 0.60 g, we had all the requirements in place in order to find the thickness of the sheet. Since D=M/V, we just plugged in the values to get an equation of 2.8=0.60/11.11*12.00*h. In order to get h isolated from the rest of the formula, we just multiplied both sides by h and divided both sides by 2.8 to get h=0.60/11.11*12.00*2.8.

Data: The found thickness of the sheet of aluminum foil was 0.016 mm.

Conclusion: In the end, the purpose of the lab was fulfilled, as my partner and I both found the thickness of the aluminum foil and were able to manipulate a common formula to our needs. I learned that if we do need to find some variables in one problem, but they aren't necessarily all provided, we can just find the values we need in one problem by doing another, granted that the other problem has the same values as the first. I feel that something that may have gone wrong during the lab would be the density of the aluminum, as we only tested one sample of the solid aluminum. So, as a result, I would test multiple pieces of aluminum to make sure that the density is in fact the correct density if I were to do this lab again in the future.

Lab 1A: Density Blocks

The purpose of this lab was to see if my partner and I could find the mass of a solid block with <2% error when given the density (Density=Mass/Volume) of a block and a ruler, which had measurements for every tenth of a centimeter going up to the thirtieth centimeter. 

The lab wasn't a difficult one to complete. To start out, a block of any material was given to us, as well as the block's density. Since we were supposed to find the mass of the block, and the mass of an object is equal to the density multiplied by the volume, we had to find the volume. In order to find the volume, we used the ruler provided to us in order to find the dimensions of the block. Once the dimensions were found, they were multiplied together, resulting in the volume of the block. That product and the density of the block were multiplied by each other to result in an experimental mass. Then, the block was put on a scale and the mass taken from that was compared to the experimental mass. The way it was compared was by a formula for finding how disparate the two masses were in terms of percentages, where the experimental mass is subtracted from the actual mass, and then the solution to that is divided by the actual mass, and then is multiplied by 100 in order to find the actual percentage. If the % error was greater than 2%, the teacher gives you a block of a different size, and you do the entire process over again until the % error is less than 2%.

It took three attempts before the % error was less than 2%. The first try was the hardest, with the values 39.8 grams (experimental mass) and 36.2 grams (actual mass) having a 10% difference between them. The second attempt was closer, with the masses 94.4 grams (experimental) and 96.8 (actual) only having a 2.5% difference. The third attempt was where my partner and I were able to complete the lab, with the masses 39.0 grams and 39.3 grams (experimental and actual, respectively), only having a mere 0.76% difference between them.

So, in the end, the purpose of the lab was accomplished. My partner and I were able to fulfill the requirements, as well as gain some knowledge along the way. The most important thing that I learned was that in order to really accomplish this lab successfully, you have to measure everything to a tee, as well as eye some values out to a further decimal place (i.e. On a ruler like ours, you would estimate the hundredth decimal place even though the only certain values from the ruler go out to the tenth decimal place) so you can try to be as accurate as possible. Some possible failings of this lab would be that the values, if not measured correctly enough, would lead to failure. So, as a result, when you eye the hundredth decimal place, you want to be as sure in those values as you can be so that you don't have to do the lab again. And, in the future, if I were going to do this lab again, I would want to see what a ruler with centimeters to the hundredth decimal place would do for increasing the accuracy of the experimental mass.