Lab Report Essay

The hypothesis is rejected as the density of the pennies did not remain constant. The results show a 8% failure rate. This failure could be due to the makeup of the pennies. “In 1982, the mint introduced a penny that is 97.6% zinc and only 2.4% copper with a density of 7.2 g/mL. By comparison, the old pre-1982 copper pennies were 95% copper and 5% zinc with a density of 8.8 g/mL” (Bularzik, 2007). This is a 22% difference in density between the pre-1982 pennies and pennies made after that year. A source of error could be that pennies from this experiment were made during different years and therefore had different metal percentages.

Objectives: The lab experiment will consist of oxidation-reduction and double displacement reactions as well as titration techniques. All these components will be used in order to determine the percent composition of pennies. In conducting redox and double displacement we are able to analyze a penny and figure out the chemical composition of the product. The experiment entails careful observations and recording of evidence for a chemical reaction. In this experiment

Is the penny real relevant in our economy? There is no real need for the penny. People think pennies are a waste of tax money. Other people think that penny's are a good thing. Pennies should no longer be made because they cost more money, wastes money, and It's easier to pay.

6. How many moles of HCl are needed to react completely with all of the zinc in a post 1982 penny?

During the first trial the penny held 17 drops of water. I used a dropper to put the drops of water on the penny very slowly while taking my time. In the next two trials it held 25 and 22 drops. In the last trial it held the most drops which was 30 drops of water. I think the last penny held the most

The density of the coins is 8.47 g/cm3 which matches the density of yellow brass the coins recovered are yellow brass

Are pennies better clean or dirty? Clean, of course. Clean pennies are probably used more than dirty pennies, but maybe just clean all the dirty pennies with the products: orange juice, coca cola, and taco sauce and see which one cleans the pennies the best, so then just use those. If any of these products cleans pennies, then coca cola will clean the pennies the best. For independent variable it was the products and the dependent variable is the clean pennies. The control group is the coca cola and the experimental group is orange juice, coca cola, and the taco sauce. For this experiment there was only a few steps to do in order to have clean pennies. After all the materials are ready then pour the products into cups and put at least two pennies in each product. Once the products are in the cups then set timer for 30 minutes and repeat this step for three trials. Collect the weight of the pennies after 30 minutes each time and write it down to see which of the products took off most of the dirt on the penny. Collect all the other data that is needed. This is just one way that cleans pennies but

Data and observations: Substance(s) Trail 1 Trail 2 Trail 3 Penny with soap 3 drops 2 drops 3 drops Penny with water 9 drops 11 drops 8 drops Penny with soap and water together 5 drops 4 drops 5

To begin, we formulated a method in which each unknown substance and compound were compared to find their molar relationships. In the experiment we calculated the molar mass of every compound by determining the amount of moles per gram in each element using the periodic table and then added them together. We then

The purpose of this experiment was to see if the three objects presented were made of the same material. The objects presented were a cylinder, cube, and a rectangular prism. Through examining the physical properties of the objects the best possibility in finding the substance of each object was through finding the density. Density is defined by a physical property between the mass and the space taken up by the substance. Density is found by using the formula mass divided by volume.

The purpose of the Density/Graphing Mini Lab was to determine how the density of a small amount of a substance relates to the density of a large amount of the same substance. The density of a substance is determined by the mass (resistance to change in acceleration) and the volume (how much space it takes up). To calculate density the formula used is, F = m/v. Mass is measured in g, volume is measured in mL, and density is measured in cm³. The hypothesis, “If the density of a small amount of a substance is compared to the density of a large amount of the same substance then they densities will be the same because the ratio between mass and volume remains the same,” was proven true as when mass is increased, volume increased as well at the same

1. In the four structures displayed, two of them are repetitive and identical. Generally, the placement of the hydrogen atom and the hydroxyl group on a designated carbon site after norbornene is hydrated is determined by Markovnikov's rule. Markovnikov's rule indicates the location of the hydrogen and hydroxyl group when the ends of the C=C double bond of an alkene are not identical.

It is in the year 2050 next to Michigan Lake. There is a scientist named Jeffrey Wilson. He is the head scientist at a lab named Lab Unextinct. At the lab they are trying to bring back bold extinct animals. They have the bones of three animals. The Animals are the Dodo bird, Sabertooth tiger and the Dakosaurus.

A hollow cylinder of metal was given to each lab group. Initially, the mass of the metal was determined with a double pan balance. The metal was placed on the balance and the instrument’s notch and slider was used to interpret the mass. The next step was determining the inner radius, outer radius and height of the cylinder to find the volume. A vernier caliper was used to measure those components. The vernier caliper included an inner and outer “jaw” that measures length. The results of the double pan balance and vernier caliper was recorded in a data sheet, and the procedure was repeated five times with different instruments. The data was placed in an excel file where the mass density, average, standard error, test of accuracy, and general comparison with the two proposed metals (gold and aluminum) could be analyzed.

Most CNC milling machines are computer controlled vertical mills with the ability to move the spindle vertically along the Z-axis. This extra degree of freedom permits their use in die sinking, engraving applications, and