Lab 2B: Atomic Mass of Candium

Purpose
 The overall purpose of this lab was to find the average atomic mass of the element Candium, To do this we had to find the masses of each of the three isotopes, decimal abundances of the isotopes, and the percent abundance of the three isotopes. From these three calculations, we were able to plug them into the average atomic mass formula and get the average atomic mass.
 Conclusions
1. The group we asked had an average atomic mass of 1.58 g while ours was 1.423 g. This difference might be because of a difference in the number of isotopes(M&Ms). The other group also could have had a number of different sized isotopes. There were also confusions between the pretzel and peanut isotopes.

2. The difference would be smaller. This is because if a bigger data set was used, more accurate results would show as the chance of error would decrease and there would be less differences between the decimal abundances.

3. No, but it would be similar. This is because the average atomic mass is a general value, calculating a value of which all of the isotopes' atomic mass is around. Hence, one Candium would be close or similar to the atomic mass and highly unlikely to have the same mass as there are many other isotopes included in the calculation.

4.

Lab 2A: Chromatography Lab

Questions

1. It would get soaked and the water would not spread out like we were wanting it to. The water has to start from the wick/center and spread to the ends of the filter circle. The filter paper should not be in contact with the cup because the ink spots will just dissolve in the water.

2. The marker/type of ink and the designs put on the filter paper circle.

3. Physical properties of the pigment makes some colors travel at different rates(faster than others). Components that are not strongly absorbed onto the paper will spend more time in the solution and will move up the paper faster. This "partitioning" of the components of a mixture between the paper and solvent separates the components and gives rise to different bands. If the components of the mixture are colored, then these bands are easy to see.

4. The blue pigment does appear commonly along the edges of the chromatograph and is always the same. Therefore, the pens do appear to contain common pigments. To achieve a single color for the pens or markers, multiple pigments are used to get the right color or shade.

5. Only water-soluble pens are used in this lab because water-soluble pens' ink is able to travel/dissolve in water. If a different type of ink/pen would have been used, then the colors would not separate. Therefore, a different substance would be needed instead of water to make the colors separate.

Lab 1B: Aluminum Foil thickness

Procedure

 First, we had to figure out the mass of the aluminum which we received. Then, we calculated the mass of the aluminum by calculated the water displacement in a graduated cylinder. From this we divided the mass and the volume to get the density. Then, we measured the length and width of the aluminum foil in centimeters. In this case, height was the thickness of the aluminum foil. We also had to find the mass of the aluminum foil, which we weighed on the weighing scale. Since density=mass/volume we then plugged in the values we knew and broke the volume part of the equation apart. Hence, the volume part became length x width x height. Therefore, we only had one unknown(the height(thickness)). Then we multiplied the volume by the density and divided both sides by the coefficient of the expression(27839.84mmH=0.46g(h stand for height/thickness)). This in turn gave us the variable H, which was the thickness. In the end, we had to convert from millimeters to centimeters.  The important materials needed for this lab was an aluminum block, aluminum foil, ruler, pen, paper, computer, calculator, graduated cylinder, and water.

Data

 We found out that the mass of the aluminum block was 80.3 g. From this we figured the volume of it by using the water displacement method which 30 mL. From this, we divided the mass by the volume and found the density, which was 2.68 g/cm^3. Then, we figured out the length and width of the aluminum foil which was 10.6 cm and 9.8 cm, respectively. From plugging this into the density equation, we found that the thickness was 0.0165 mm.

Lab 1A: Density Block Lab

Introduction
My partner, Luis, and I calculated the mass and compared it to the mass of the actual mass of the block. From this we calculated the percent error((actual-experiment)/actual x 100%)). Percent error shows you how precise your result is compared with the actual "result". The purpose of this lab was to determine the mass of a plastic block using its density and volume. Density is the result of the mass of an object(amount of matter in an object) divided by the volume of the object (how much space it takes up).

Procedure
My partner and I selected different density blocks and then measured the length, width, and height to find the volume. After figuring out the volume, we multiplied it by the density of the block (which was given on the density block) to figure out the mass of the block. Then, we weighed the block to figure out the actual mass and then calculated the percent error. We went through 5 trials to get our lowest percent error. The important materials needed for this lab was a plastic block, weighing scale, ruler, pen, and paper.

Data
Our lowest percent error was 2.84%. For this block we found that the length of the block was 7.3 cm, the width being 3.3 cm, and the height being 2.4 cm. From this the volume was 57.816 cm^3. The density, given on the block, was 1.42 g/cm^3. Hence, our calculated mass was 82.1 g and the actual mass was 84.5 g. The percent error for this trial was 2.84%.

Conclusion
We partially fulfilled our purpose of the lab as our calculated mass  We determined the mass of a plastic block by figuring out the volume and using the density given. The reason why our percent errors were very high on many of our trials was maybe because we were a little off when measuring the length, width, and height of the block. I learned that accuracy plays a very big part in measurements, as even if we were a little off in our measurements, we had a magnificent difference between the actual and calculated mass of the block. In the future, I will make sure to make more accurate measurements.