BE
SURE TO LEAVE EVERYTHING THE WAY THAT YOU FOUND IT FOR THE NEXT STUDENT. The
object goes back into the cup, and must be dry, and the slides on the balance must be placed back on the left side.
Lab Table 4: Determine the mass in grams of one of these rubber stoppers using one
of these digital balances. Record this measurement in black or blue ink in a
table in your laboratory notebook. Be sure to record in your lab notebook which
balance you used.
Step
1 tare the balance. Tarring means pressing the start button a 2nd time to make sure that the balance read 0.00 grams
when nothing in on the balance pan.
Step
2 make sure that the balance is set
to measure the object in the correct units. We measure everything in the metric
system and mass in the metric system is usually measured in grams (g) or kilograms (kg).
Step
3 when you are finished, remove the
stopper from the balance pan and turn off the balance before the next student
starts their measurements.
Lab
Table 5: Determine the mass in grams of one of the rubber stoppers using one of these triple beam balances. Record this measurement in black or blue ink in a table in your laboratory notebook. Be sure to record in your lab notebook which balance you used.
Step
1 tare the balance. Tarring is the process of making sure that the mark on the end of the balance beam lines up perfectly to
the mark adjacent to it on the balance body.
Step
4 when you are finished, untare the
balance (give the taring knob a spin with your fingers).
Lab
Table 6: Determine the temperature of the water in one of the Erlenmeyer flasks.
Record this measurement in black or blue ink in a table in your laboratory notebook.
Be sure to indicate in your lab notebook which thermometer, Erlenmeyer flask, and hotplate you used.
Draw
an illustration of the Erlenmeyer flask in your lab notebook and label it Erlenmeyer flask.
Draw
an illustration of that part of the thermometer around the point to which the alcohol has risen (the point where the red liquid
comes to).
Write
an explanation in black or blue ink, in your lab notebook, for how you determined the correct number of significant figures
for this measurement.
Step
1 hold the bulb of the thermometer
in the water without letting it touch the sides or bottom of the Erlenmeyer flask. Hold
the thermometer in the water until the red alcohol stops moving.
Step
2 determine the temperature to the
correct number of significant digits and record this in your table in your notebook.
Step
3 remove the thermometer, rinse it
off using the sink on the lap table, dry it off, and place it on a paper towel beside to the hotplate that you used.