Chemistry Experiment Essay

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

11. Tare the scale by pressing the Φ/T button so that the scale reads 0.0 g.

Did the coin have to be a penny? Explain. I believe that the coin didn't need to be a penny. For this journal, the same quantity of exterior area is needed so if you use pennies, cents or dimes, it does not matter if you use all same coins in the lab, the only thing that would have changed is the amount of drops.

Weight 30 dry pre-82 pennies which get 89.77g, using 30ml initial volume measuring the volume of 30 pennies, record the data 10.0ml. Using equation Density= Mass/Volume, get the density of the pre-82 pennies is 8.98g/ml. Then calculate the error%=0.10%, and the deviation%=1.29%.

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

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)

4. Predict: What do you think is the density of the whole block of Styrofoam? 0.2 g/cm3

H. How would you prepare 10 mL of a 0.25M HCl solution if 1M HCl was available? How much

Write a balanced chemical equation for each reaction #1-8. Classify each reaction using the information provided in the

D. A sample of gold (Au) has a mass of 26.15 g. Given that the theoretical density is 19.30 g/mL,

5. A local grocery store was holding a contest to see who could most closely guess the number of pennies that they had inside a large jar. The first six people guessed the numbers 735, 209, 390, 300, 1005 and 689. The grocery clerk said the jar actually contains 568 pennies.

The purpose of the lab was to determine the ratio of air to acetylene results in complete combustion of acetylene gas. The balanced chemical equation for this experiment was C2H2(g) + O2(g) --> CO2(g)+ H2O(l). Complete combustion is the reaction of an element or compound with oxygen to produce the most common oxides and energy. Complete combustion occurs when the fuel and oxygen combine in exact proportions to completely burn the fuel, which leaves a clean test tube. Incomplete combustion is the reaction of an element or compound with oxygen to produce some oxides with less oxygen than the most common oxides. Incomplete combustion occurs when there is not enough oxygen to react

If the water displacement increases, then the density will decrease because the mass will be divided by a higher volume causing a lower density. The independent variable is the water displacement and the dependent

During this time, there were a number of different gold extraction techniques that involved mercury [3]. The common rocker, which looks similar to a child’s crib, was

In the third stage of this experiment, the density of a liquid was determined and compared to known standards. A 100ml beaker was filled to about half-full with room-temperature distilled water. The temperature of the water in ◦C was recorded in order to compare to known standards later. A 50ml beaker was then weighed on a scale in order to determine mass and recorded. A sample of the distilled water with an exact volume of 10ml was then placed in the 50ml beaker using a volumetric pipette. The 50ml beaker with the 10ml of water was then weighed again and the initial mass of the beaker was subtracted from this mass to obtain the mass of the 10ml of water. With the volume and the mass of the water now known, density was calculated using d = m/V and recorded in g/ml. This process was then repeated to check for precision and compared to standard values to check for accuracy. Standard values were obtained from CRC Handbook, 88th Ed.