Lab Report Density Lab

Density was an important part of this lab. Density can be defined as the ratio of the mass of an object to the volume. To find the density of an object, simply divide mass and volume. The equation looks like this: D=M/V. Density is an intensive property that depends only on the composition of a substance, not the size of the sample.

This experiment was performed to determine the difference in density between pre-1982 pennies and post-1982 pennies. In addition, we were given an unknown substance and our task was to configure what it was through calculating its volume,mass, and density. Furthermore, we were being introduced to the procedures of displacement in this experiment as well. All together, we were given the task of finding out why there was a difference in density between the two pennies. My partner, Michael Sapawa, and I first had to measure the mass of both pennies using a scale. Then we calculated the volume of the samples with graduated cylinders through the method known as displacement. We then applied our schema and drew out the formula for density, which

Experiment 2 “Density” was about how to measure the mass and volume and determine the density of water, alcohol, and a solid. For this lab, we begin by calculating the mass of empty graduated cylinder and the mass of 25 mL of tap water. After taking the mass of water and cylinder, we record it on “Density of Water: Data Table”. Since we did not have enough time of complete the whole lab, so we skipped the procedure to measure the density of alcohol. We jumped to the next procedure, which was density of a solid. For that we used a copper and it density 8.95. For this lab, my partner and I did not make any mistakes or errors. But, for better improvement I think we should have more time to complete the whole lab. I felt like we was rushing through

If I fill up two different containers with different amounts of water, then I will be able to understand the density of the two different mass/volumes of two different containers.

I took the graduated cylinder and started filling it up with water until the bottom of the meniscus was to the the 100.0 mL mark with the assistance of a dropper pipet. I then took the 13 x 100 mm test tube and slowly poured the water from the graduated cylinder into the test tube until it was full to the top. I then poured the water in the test tube out into the sink and put the graduated cylinder on the counter so I can get an accurate measurement of the lower meniscus to record on my data table. I once again followed the same procedure again filling a second test tube with water from the graduated cylinder then setting it on a straight surface to get an accurate measure of the volume to

CHM130 Lab 6 Exploring Density Name A. Data Tables Place your completed Data Tables here Part IIIa (3 points) Volume of water in graduated cylinder (mL)10 mlMass of rubber stopper (g)11.15Volume of water and rubber stopper (mL)16.5 Part IIIb (6 points) Volume of water in graduated cylinder (mL)20Mass of iron nail (g)3.66Volume of water and iron nail (mL)20.5 Part IV (20 points) Type of Aluminum FoilMass (g)Length (cm)Width (cm)Volume (cm3)Thickness (cm)Regular.63g15 cm 10.02 cm.21 cm3.0014 cm Heavy Duty.97g15 cm10.01 cm .36 cm3.0024 cm B. Follow Up Questions Show all work for questions involving calculations. Part I Use the concepts/vocabulary of density to explain why the liquids formed layers in Part I of the procedure. (8 pts)

Introduction: Accuracy and precision were the major aspects of the lab. Accuracy is how close the average of the measured values are to the actual value. Precision is the closeness of repeated measurements. In the lab, the aim was to get as close as possible with both accuracy and precision when determining the mass and volume of the spheres. The mass was determined by weighing the spheres on the Analytical Scale and Triple Beam Balance Scale. The volume is determined by measuring with a ruler and by water displacement. The standard

With volume and mass determined, the density formula (d = m/V) was used to determine the densities of each rock and recorded in g/ml.

Conclusion: The purpose of this lab was to find the relationship between the mass and the volume of the four samples. The densities from least to greatest were shortest(4), short(3), medium(2), and longest(1). Density can vary with temperature, and that could cause errors in the collected data. A real world application of density is icebergs. Icebergs float because they are less dense than the water around them. The icebergs are made of frozen freshwater but they are surrounded by very cold salt water. Initially, salt water has a higher density than freshwater and the low temperatures of the water cause the density to increase even more. The salt water and its increasingly high density allows for the less dense icebergs to float. Knowing this about density is good to know so we can figure out how things in the world work, like how and why massive icebergs float in the middle of the

The pennies that were dropped into the graduated cylinder could have caused some of the water to splash out of it. This may have caused an error in measuring the volume, this would have caused the volume measured to be less than the actual volume, thus allowing the density of the pennies to increase, causing the lab results to be uneven. Another source of error has to do with the mass of the pennies. After the pennies were taken out of the graduated cylinders filled with water, there was still some water droplets left on the pennies when put on the triple beam balance. This extra weight of the water may have caused the measurement in the mass of the pennies to be more than they actually were. This outcome could have caused the density of the pennies to be increased as well, making the lab results inconstant. Any type of coating, for example rust, on the penny may affect the mass. This will add to the mass making it higher, and since density is proportional to the mass, the density will be calculated higher than what it actually

This most likely caused some of the masses measured to be incorrect. Another problem we faced was the wooden ball. Since it floated in the water, we had to push it under the water with the tip of a pencil. This might have impacted the volume. 6.

The objective of the density determination lab is to determine/compare the average density of pre-1982 and post-1982 pennies. This can be achieved by finding the mass to volume ratio then averaging the results. The purpose of this lab is to find out if the difference in composition of the pre and post pennies will affect their densities. Pennies made before 1982 where majority copper but pennies minted after 1982 are made with mostly zinc. With this background knowledge, we expect the outcome to be that the density of the pre-pennies will be greater than the post-pennies. This experiment will help us to determine if the pre pennies will have a higher density by finding the volumes and mass’s then comparing the results.

2. (5 pts) List and explain the names and affiliations of the various characters/stakeholders in this story – I’m looking for us to use the story to map out the complexities that are generally associated with solving public health puzzles – the stakeholders you list and explain here should apply to many of the cases we consider going forward.

In 1909 S.P.L. Sorensen published a paper in Biochem Z in which he discussed the effect of H1+ ions on the activity of enzymes. In the paper he invented the term pH to describe this effect and defined it as the -log[H1+ ]. In 1924 Sorensen realized that the pH of a solution is a function of the "activity" of the H1+ ion not the concentration and published a second paper on the subject. A better definition would be pH=-log[aH1+ ], where aH1+ denotes the activity of the H1+ ion. The activity of an ion is a function of many variables of which concentration is one. It is unfortunate that chemistry texts use a definition for pH that has been obsolete for over 50 years.

Furthermore, the measurements from a wooden block and a metal object were taken to calculate their volume and density. In this case, the calculations were more precise but due to other sources of errors, which may be systematic, random or personal, the data was not 100% accurate. There are always certain uncertainties associated with any type of measurement and it is important to know that no measurement will be one hundred percent correct.