ment, such as the meterstick, the graduated cylinder and the thermometer and to reinforce the SIsystem. We will also be testing for precision in these experiments. Hypothesis: If the lab equipment that we are using is accurate than ourresults will turn up about the same each time we do the lab.
Procedure:Experiment A: First obtain a meter stick. Then measure the length andwidth of your lab book in inches, meters, millimeters and centimeters. Record your results. Next use the standard calculations to check ifyour measurements correspond.
Finally find the volume of the lab bookin cm2. Experiment B: First fill the graduated cylinder about half full. Readwhat the volume of the water is to the nearest 0. 1mL (make sure youread the volume at the bottom of the meniscus). Record your results. Next determine the maximum volume your test tube will hold.
Recordyour results. Experiment C: Acquire 40mL of water in a 150mL Erlenmeyer. Then weigh andrecord the mass of a 50mL Erlenmeyer to the nearest 0. 1mg.
Nextmeasure and record the temperature of the 40mL of water. Using thepipet, pipet exactly 10mL of water into the Erlenmeyer and weigh it tothe nearest 0. 1mg. Next find the net mass of the 10mL of water.
Todo this, subtract the mass of the Erlenmeyer from the gross mass ofthe water and the Erlenmeyer. Do these there times to make sure youare precise. Next find the mean volume delivered by the pipet. To dothis, add the three net masses and divide by three. Next find theindividual deviation from the mean.
To do this, subtract theindividual volume by the mean volume. Next find the average deviationfrom the mean. To do this, add the three deviations together anddivide by three. Experiment D: First weigh a dry 50mL flask to the nearest 0. 1mg.
Next add10mL of antifreeze to the flask with your pipet. Weigh the flask andthe antifreeze and record the mass. Do this three times. Use themeasured mass and the volume to determine the density.
The formulafor this is D = m/v. Using these values measure the mean density andthe average deviation from the mean. This is done like it was done inexperiment c. Calculations: See attached pagesData: See attached pagesResults: After concluding these experiments, I concluded that the labequipment that we used is accurate. My hypothesis was correct. Inthese experiments it was really important that the readings that weretaken from the equipment was very accurate and precise.
It needs tobe both of these to be correct. This is because if you were accuratein the findings, but each time the readings were off, the mean wouldbe of too. Also if you were precise, but not accurate, then theanswer would be completely off. After doing this experiment, I nowbetter know the SI system and I better now how to use lab equipment.
