September 6, 2012
September 13, 2012
This lab contains four different experiments. All four experiments focus on proper laboratory techniques. The reasoning behind this lab was to become familiar with lab equipment, the proper usage of lab equipment, and how to correctly take data and notes. The first experiment of this lab was to determine the volume of water in various types of equipment. The second experiment was to measure the different masses of pennies from pre and post 1982. The third experiment was to calibrate and measure the volume of a 5-ml pipette. The last and final experiment of this lab was to record the temperature of boiling and frozen water and to calculate the true boiling point of water at the given atmospheric pressure.
Laboratory 1 is deigned to prepare students for further labs. Lab 1 allows students to practice their skills at reading data from various types of equipment. It teaches students how to use a Bunsen burner, graduated cylinders, burettes, Erlenmeyer flasks, and a balance. Besides just allowing the users to gain experience using different types of equipment, this lab will improve the users performance in solving problems of density, volume, mass, average, and deviation. In order to solve for density, volume, or mass the following equation can be used: D = M/V. The average is found by adding all of the products together and then dividing the sum by the number of products and deviation is found by taking the highest product and subtracting that by the smallest product. I am sure that the methods of this lab will be used again in another lab.
In procedure 1 the level of water must be recorded for four different pieces of equipment. The four pieces of equipment are a 100-mL graduated cylinder, 10- mL graduated cylinder, 50- mL burette, and a 250-mL Erlenmeyer flask. When reading the levels of water in different pieces of equipment you must use a white card with a piece of black tape to help you see the meniscus more clearly. Once all the levels of water are measured, you must also write down the level of uncertainty for each piece of equipment. The levels of uncertainty are usually on the equipment if not there is a chart in the lab manual. Procedure 2:
The first step in procedure 2 is to collect four pre-1982 pennies and four post-1983 pennies. Once all the pennies are collected, grab a weighing paper and head to a balance. Tare the balance with the weighing paper on the balance; therefore, the weight of the weighing paper is not included in the calculated weight of the penny. By placing one penny at a time, record the mass and year of all eight pennies. Finally, calculate the average mass and deviation for all pre-1982 pennies and for all post-1932 pennies. Procedure 3:
Procedure 3’s main purpose is to give the user an understanding behind the purposes and usage of a pipette. To start the procedure obtain approximately 50-mL of deionized water in a beaker and record its temperature. After obtaining the 50-mL of deionized water in a beaker and recording its temperature, find a 125- mL Erlenmeyer flask and weigh it. Before weighing the flask, make sure the balance is zeroed. The next couple of steps will require you to use the pipette, but before you use it you need to clean the pipette out. To clean the pipette fill the pipette with 5-mL of deionized water and then let the water drain out. The drainage of the water will clean the pipette. Now that the pipette is clean fill it again with 5-mL of deionized water and drain the water into the previously weighed Erlenmeyer flask. Take the flask to the balance and weigh it with the water in the flask. Record your weights and then repeat the procedure of filling your Erlenmeyer flask with 5-mL of water using a pipette and weighing it out two more times. Once all the data is collected...