Lab Report Essay

because each of the objects displaced the water by 1 mL, their mass over that mL is their density.

The objectives of this lab was to determine the density of pennies minted in different years. Then to compare the densities of those pennies to see what change or changes occurred in the composition of the pennies. And finally, to try to identify possible metals in the cores of the pennies.

Purpose: Weighing objects. Figuring out the density with an object by calculated volume and Archimedes’ Principle.

This hypothesis is based off of the idea of water density and how it changes when a substance is added or removed. A material's density is defined as its mass per unit volume. It is, essentially, a measurement of how tightly matter is crammed together (Jones, 2015). Every matter in the world has its own specific density. Density can be calculated by multiplying the mass times the volume. Water's density can change when a substance is added or when the temperature is increased or decreased with the normal density of water is just under 1 gram per

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.

This experiment was performed to observe differences in density based on the chemical makeup of an object. Pennies minted before 1982, pennies minted after 1982, and an unknown metal sample was tested to see if there were any differences in their densities. Ten pennies from each category and the metal sample were weighed using a scale to find mass and the displacement method was used to find their volumes. The masses and volumes were then used to calculate the densities of the pennies (D=m/v). The density of the pre-1982 pennies were 8.6 g/mL while the post-1982 pennies were 6.9 g/mL. The metal sample’s density was 1.7 g/mL. Following the experiment we were given the real densities of each item to calculate the percent error with the formula

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)

2. In order to calculate the density of a solid or liquid sample, what measurements are needed?

For example, how to physically find the density of an object by finding their mass with a balance and finding the object's volume using the method water displacement. The purpose of the experiment was to find out which metal is used to create post 1982 pennies. Pre-1982 pennies were made out of copper but then the metal used for making pennies changed. The metal used to create pre-1982 pennies was copper. Since the metal used to make pennies changed the density of post-1982 changed.

In Measuring and Understanding Density, several experiments were performed to find density of regularly shaped objects, irregularly shaped objects, liquids and gasses. An additional experiment was done to find the specific gravity of a sampling of liquids. The purpose of the experiment was to provide a better understanding of density and to be able to extrapolate unknowns based upon these calculations. The experiments yielded data in keeping with Kinetic-molecular theory in regards to the density of water versus its temperature. Key measurements and formulae were also used to determine densities of metal and plastic objects as well as irregularly shaped rocks. It is possible to find the density of an object (be it liquid, gas or

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

In this project, C. Elegans are hermaphrodite worms that will be used since they are easy to maintain in lab, as well as have short life cycles. The gene that the project attempted to knockdown in C. Elegans with RNAi treatment is the unc-22 gene. RNAi disrupts gene expression in the presence of double stranded RNA (dsRNA) that is complementary to target gene sequence. The unc-22 gene codes for a muscle protein called twitchin in wild-type worms. The Unc-22 is required for muscle regulation and maintenance in C.Elegans. To verify that the RNAi treatment worked, would check the unc-22 mRNA levels in the worms, in addition to phenotype observation.

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.

If anyone else would like to carry out this experiment in the future, I recommend doing it on a surface that you don't mind getting dirty, as this eperiment was very messy. Mostly because I accidently spilled things. This experiment can be applicable to real life as density is very important in some scientific jobs like chemist or astrologist because density is a very important in those

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.