Name ________________________
Block ______________
Comparing the Accuracy of Liquid Measuring Devices
Chemistry – Ms. Drommerhausen
Materials:
10 mL Pipette
400 mL beaker
25 mL graduated cylinder
50 mL buret
100 mL graduated cylinder
distilled water
150 mL beaker
electronic balance
100 mL beaker
Introduction:
Different liquid measuring apparatuses vary in the degree of accuracy which they
measure the volume of a liquid. Five different apparatuses, a 10 mL pipette, a 25 mL graduated
cylinder, a 100 mL graduated cylinder, a 150 mL beaker, a 100 mL beaker, and a 400 mL beaker
will measure 10 mL portions of water. A 150 mL beaker will be used to receive the 10 mL of
water being measured by each device. The precision of each instrument (assuming they are used
correctly) will be determined by measuring the mass of the 10 mL portions. Since water at room
temperature has a density of 1.00 g/mL, we can assume that the mass of 10 mL of water (if
measured precisely) would have a mass of 10.0 g. By comparing the total mass of the water for
each measuring device (10 mL portions) to the expected mass of 10.0 g, it is possible to
determine which has the precision measuring 10 mL of water.
Procedure:
1. Record all data in the data table provided
2. Weigh a dry 150 mL beaker to the nearest .01 g on the electronic balance
3. Using a 10 mL pipette, pipette 10 mL of water into the dry 150 mL beaker (use a pipette
bulb when pipetting and touch the point of the pipette against the beaker to allow it to
drain properly).
4. Weigh the beaker and the water to the nearest 0.01 g and record the mass in the data
table.
5. Dry the 150 mL beaker, reweigh and repeat the procedure with the 50 mL buret, then a
25 mL graduated cylinder, a 100 mL graduated cylinder, a 100 mL beaker, and finally the
400 mL beaker
6. Use the information provided in the calculation portion of your data sheet to determine
the volume of water delivered by each instrument.
7. When you are finished, dry all equipment and return it to its proper place.
Data Table
10 mL pipette
50 mL buret
Mass of the beaker + water __________ g
Mass of the beaker + water __________ g
Mass of dry beaker (150 mL) __________ g Mass of dry beaker (150 mL) __________ g
Mass of water
__________g
Mass of water
___________g
25 mL graduated cylinder
100 mL graduated cylinder
Mass of the beaker + water __________ g
Mass of the beaker + water __________ g
Mass of dry beaker (150 mL) __________ g Mass of dry beaker (150 mL) __________ g
Mass of water
__________g
Mass of water
___________g
400 mL beaker
100 mL beaker
Mass of the beaker + water __________ g
Mass of the beaker + water __________ g
Mass of dry beaker (150 mL) __________ g Mass of dry beaker (150 mL) __________ g
Mass of water
__________g
Mass of water
___________g
1. List the measuring devices from the most accurate (closest to 10.0 g) to the least accurate
a. ______________________
b._________________
c. _______________
d. ______________________
e. _________________
f. ________________
2. Why is it difficult to accurately measure 10 mL of water with a 400 mL beaker
3. Based upon the accepted value of 10.0 g of water being measure by each instrument,
calculate the percent error for the most accurate and the least accurate instruments. Show
your work with units and remember sig figs!!!!
a. Least accurate instrument
b. Most accurate instrument