ment, such as the meterstick, the graduated cylinder and the thermometer and to reinforce the SI
system. We will also be testing for precision in these experiments.
Hypothesis: If the lab equipment that we are using is accurate than our
results will turn up about the same each time we do the lab.
Experiment A: First obtain a meter stick. Then measure the length and
width of your lab book in inches, meters, millimeters and centimeters.
Record your results. Next use the standard calculations to check if
your measurements correspond. Finally find the volume of the lab book
Experiment B: First fill the graduated cylinder about half full. Read
what the volume of the water is to the nearest 0.1mL (make sure you
read the volume at the bottom of the meniscus). Record your results.
Next determine the maximum volume your test tube will hold. Record
Experiment C: Acquire 40mL of water in a 150mL Erlenmeyer. Then weigh and
record the mass of a 50mL Erlenmeyer to the nearest 0.1mg. Next
measure and record the temperature of the 40mL of water. Using the
pipet, pipet exactly 10mL of water into the Erlenmeyer and weigh it to
the nearest 0.1mg. Next find the net mass of the 10mL of water. To
do this, subtract the mass of the Erlenmeyer from the gross mass of
the water and the Erlenmeyer. Do these there times to make sure you
are precise. Next find the mean volume delivered by the pipet. To do
this, add the three net masses and divide by three. Next find the
individual deviation from the mean. To do this, subtract the
individual volume by the mean volume. Next find the average deviation
from the mean. To do this, add the three deviations together and
divide by three.
Experiment D: First weigh a dry 50mL flask to the nearest 0.1mg. Next add
10mL of antifreeze to the flask with your pipet. Weigh the flask and
the antifreeze and record the mass. Do this three times. Use the
measured mass and the volume to determine the density. The formula
for this is D = m/v. Using these values measure the mean density and
the average deviation from the mean. This is done like it was done in
Calculations: See attached pages
Data: See attached pages
Results: After concluding these experiments, I concluded that the lab
equipment that we used is accurate. My hypothesis was correct. In
these experiments it was really important that the readings that were
taken from the equipment was very accurate and precise. It needs to
be both of these to be correct. This is because if you were accurate
in the findings, but each time the readings were off, the mean would
be of too. Also if you were precise, but not accurate, then the
answer would be completely off. After doing this experiment, I now
better know the SI system and I better now how to use lab equipment.