Investigating Precision And Accuracy Of Experimental Measurement Essay

Purpose: To learn about the international system of units (SI), to become familiar with common lab equipment and techniques, to gain proficiency in determining volume, mass, length, and temperature of a variety of items using common laboratory measurement devices, to learn to combine units to determine density and concentration, and to use laboratory equipment to create serial dilutions and determine the density and concentration of each dilution.

Purpose: To become familiar with the International System of Units and common laboratory equipment and techniques. To learn how to determine volume, mass, length, and temperature of a wide variety of items. To learn how to calculate density and concentration of dilutions.

7.The air dried filter paper was then placed on the weighing scale and results were recorded

Procedure: Using distilled water, premeasured containers and objects determine displacement of fluids and density of objects. Use ice and heat measure temperatures in Celsius, Fahrenheit and Kelvin.

To perform this test, a small drop of water is placed on a clean microscope slide. A metal loop that has been properly sterilized in the blue flame and allowed time to cool is used to

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.

11. The experiment was repeated three more times using different water temperatures (room temp water, cold temp water, hot temp water).

Abstract: The objective of the lab is to determine the volumes of the polystyrene spheres with three different measuring tools: Water Displacement, Analytical Scale, and Triple Beam Balance Scale. The experiment is meant to help understand the concept and application of precision and accuracy in experimental measurements. Accuracy is a measure of how closely the results of repeated measurements are to the true value of what is being measured. Precision is the variability in the results from the repeated measurements, and how close the repeated measurements were to one another. In this lab, the method for measuring the volume of the polystyrene spheres is done with the previously stated tools: Water Displacement, Analytical Scale, and Triple Beam Balance Scale. The standard deviation for the entire classes volumes and masses are recorded to determine the densities.

The next step in this lab is to rinse the Erlenmeyer flask with distilled water down the drain and then repeat the experiment, this time adding 10 ml of 0.10M KI and 10 ml of distilled water to the flask instead. The flask should again be swirling to allow the solution to succumb to the same temperature as the water bath and once it has reached the same temperature, 10 ml of 3% H2O2 must then be added and a stopper must be immediately placed on the flask and recording should then begin for experiment two. After recording the times, the Erlenmeyer flask must then be rinsed again with distilled water down the drain. After rinsing the flask, the last part of the lab can now be performed. Experiment three is performed the same way, but instead, 20 ml of 0.10 ml M KI and 5 ml of distilled water will be added and after the swirling of the flask, 5 ml of 3% H2O2 will be added. After the times have been recorded, data collection should now be complete.

Abstract: This experiment introduced the student to lab techniques and measurements. It started with measuring length. An example of this would be the length of a nickel, which is 2cm. The next part of the experiment was measuring temperature. I found that water boils around 95ºC at 6600ft. Ice also has a significant effect on the temperature of water from the tap. Ice dropped the temperature about 15ºC. Volumetric measurements were the basis of the 3rd part of the experiment. It was displayed during this experiment that a pipet holds about 4mL and that there are approximately 27 drops/mL from a short stem pipet. Part 4 introduced the student to measuring

To achieve a good volumetric technique, the experimenter needs to be able to correctly complete certain procedures.

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.

The volume of a small test tube and a thin-stemmed pipet were determined in this section of the lab. Water was poured into a small test tube until the water reached the very top edge of the test tube. The test tube was then emptied into a plastic 25 mL graduated cylinder and volume was measured and recorded into data table 3. A think-stemmed pipet was completely filled with water. Drops were carefully counted and emptied into the empty plastic 25 mL graduated cylinder until the water level reached 1 mL. The number of drops in 1 mL was recorded into data table 3. The thin-stemmed pipet had a total volume of 4 mL and that was also recorded into data table 3.

The eggs were each individually placed in one of the beakers and were taken out and weighed every 15 minutes for 60 minutes. Weighing the eggs helped to test the process of osmosis by finding out the mass before and after soaking in water, this will dictate whether water has moved in or out of the egg.

A volumetric pipette & measuring cylinder can be calibrated by just weighing the water they deliver. As for volumetric flask, the weight of an empty flask is recorded. Next, weigh the flask after filling it with water to the mark.