1 Arizona State University School of Molecular Sciences
How is Lab Glassware Used?
In general chemistry lab, you will come into contact with common laboratory glassware,
such as, beakers, Erlenmeyer Flasks, volumetric flasks, pipettes, burets, and graduated
cylinders. Beakers and Erlenmeyer flasks are usually to hold liquids throughout an
When you look closer at each glassware, you’ll notice markings on each
measure specific volumes.
Glassware is generally divided into two types, those that
certain volumes and those
The purpose of this investigation is to find the most precise and/or accurate glassware
based on the average lowest % error.
is the how close a measured value is
to the actual (true) value.
is the repetition of measurements under
unchanged conditions and shows the same results.
The more precise and accurate a
measurement is, the less error with density calculations expressed, using significant
(g/mL or g/cm
) is the substance is its mass (grams) per unit volume
(mL or cm
), in other words,
are used as the number of digits that carry real information about a
measurement. There is no such thing as a perfect measurement.
Which is why usually
in an experiment, repeated trials are recorded to ensure verifiable data.
The objective is
to determine the relationship between percent error, and measurement accuracy
throughout the experiment.
Every lab equipment has some degree of uncertainty so you can estimate one more
digit past the smallest division on the measuring device. For example, for a 10mL
graduated cylinder the smallest graduation is tenth of a milliliter (0.1mL). That means
when you read the volume, you can estimate to the hundredths place (0.01mL).
However, some glassware such as volumetric flasks and volumetric pipettes only have
a single line to indicate volume. This is because they are made to measure just one
specific volume. In the case of the glassware used in general chemistry lab, both the
10mL volumetric pipette and 50mL volumetric flask will have two sig figs after the
decimal point (i.e. 10.00mL and 50.00mL). For the 150mL beaker and the kitchen
measuring cup, assume that 50.mL has two sig figs (it will not be obvious based on the