Mass And Density Lab Report

Mole of chlorine : 1.0217g - .221g - .3946 g = .4061 g of chlorine

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

In this lab experiment our main focus was to get skillful in using tools such as the metric ruler, balances, thermometer, and graduated cylinder to capture measurements of length, mass, temperature and volume. Additionally, this lab helped us to become more familiar with the uncertainty of measurements, as well as becoming efficient with rounding our measurements to the correct numbers of significant figures. Our results are measured consistently with rounding to the closest answer we could possibly acquire as the data can tell you.

5. Calculate the mass of the water by subtracting “Mass A” from “Mass B.” Record the mass of the water in Data Table 4.

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

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

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

13) When the tray is thoroughly dry, determine its mass. Record the mass in the data table. You have to wait until day three to weigh the copper.

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.

The weight of each 50ml beaker (used for weighing the mass of dissolved Potassium chloride after the evaporation of water) should be recorded. If the experimenter were to weigh the mass of one beaker and take it as a default mass, the latter may be a source of error.

Seven various household objects were chosen to measure using a digital gram scale. Each object’s mass was estimated by lab students and recorded in data table 4. A quarter, ball point pen, rubber bulb, large paper clip, green crayon, house key and a copper penny masses were estimated and recorded in data table 4. Each object was placed on the scale individually and its actual measurement was recorded in data table 4. As we started estimating the household objects we were often not correct in our estimations. As we measured more and more objects, we got better in our estimations by comparing objects with known masses and comparing them with the unknown

3) Repeat the drying process just to be sure that the copper is completely dry, and again determine the mass of the copper and the beaker.

Using the direct weighing and weighing by difference methods to find weight and mass of chemicals and compounds.

One milliliter of 6.00-M phosphoric acid was placed into a 125-mL Erlenmeyer flask using a volumetric pipette. Using a slightly larger pipette, six milliliters of 3.00-M sodium hydroxide was transferred into a 50-mL beaker. Then a disposable pipette was used to slowly mix the sodium hydroxide into the phosphoric acid while the solution was swirled around. Then both the beaker and flask were rinsed with 2-mL of deionized water and set aside. A clean and dry evaporating dish was weighed with watch glass on a scale. Then the solution was poured into the dish and the watch glass was placed on top. The solution was then heated with a Bunsen burner to allow for the water to boil off to reveal a dry white solid. After the dish cooled to room temperature it was once again weighed and the new mass was recorded.

The density of water is its mass divided by its volume. In this case, the mass of water was determined by subtracting the final mass of the glassware with water by the initial mass of the glassware without water. The volume was determined by observing closely which line (marked on the sides of each glassware) the water reached and reporting the most precise measurement. Based on the class data, the average densities of water and its standard deviations were: 50-mL beaker – avg: 0.90 g/mL, stand dev: 0.12, 10-mL graduated cylinder – avg: 0.980 g/mL, stand dev: 0.0600, 10-mL volumetric pipette– avg: 0.9800 g/mL, stand. dev: 0.06499, 50-mL burette– avg: 0.969 g/mL, stand. dev: 0.140. The average density of water compares our experimental value to the true value. This means that the closer our values are to the true density of water, which is approximately 0.998 g/mL at 18.89°C, the more accurate our data is. Furthermore, the standard deviation measures how precise our results are with one another.