Chemistry 1A
Experiment 1: Density
CSUS Department of Chemistry
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Before getting started, fill a 400 mL beaker with deionized (di)
water from the center tap in the sinks.
Allow this to come to room temperature, measure the
temperature with your thermometer, Use this temperature to
find the density of water on the chart at instructors desk.
Before using the balances, be sure that you are shown the
correct way to operate them. If you break it you buy it!
You will work alone in this experiment. If I find data that has
been shared, both parties will receive a zero score and be put on
notice!
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Experiment 1: Density
•You will use different methods to measure the density of a liquid
and solid in this experiment.
•Each method has different precisions of measurement.
•You will need to keep this in mind when recording your data.
Part A: Density of a liquid
Graduated Cylinder Method: Choose a liquid from the hood,
record its identity.
Volume:
Mass:
Waste:
Read to ± 0.1 mL
Read to ± 0.01g (top loading balance)
Dispose of the waste in the Organic waste jug
in the waste hood.
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Part A: Density of a liquid
Pycnometric Method: A “pycnometer” is a flask, usually made of
glass, with a close-fitting ground glass stopper so that air bubbles
may escape from the apparatus. This enables the density of a fluid
to be measured precisely accurately.
You will need to check out your pycnometer from the stockroom.
Step 1: Rinse and dry your pycnometer before using.
Calibrate the flasks volume using water, wipe all excess
water off of the pycnometer before weighing!
All masses are recorded to ± 0.0001g using the
analytical balance.
Step 2: Using the same liquid as before, determine the
density with your calibrated pycnometer. Dispose of the
waste in the organic jug in the waste hood.
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Mass of water contained by the pycnometer
using density 
Yields volume of water contained by the pycnometer
Volume of the pycnometer
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Part B: Density of a Solid
Obtain a solid sample from your the front of the room. Use the
larger of the two samples. Record the identity.
Part1: Direct volume calculation (Larger of the two samples)
Mass:
Read to ± 0.01g (top loading balance)
Ruler:
Read to ± 0.1cm (1mm)
Part 2: Water Displacement
Using the mass from part 1, determine the volume of your solid via
water displacement.
Volume:
Read to ± 0.5 mL
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The level of the liquid rises
due to displacement.
The difference in volume is
the volume of the object.
8.5 mL
5.0 mL
All volumes using this
method must be reported
to  0.5 mL.
3.0 mL
8.5 mL
The volume is accurate
because the liquid fills
in completely around
the irregular shape!
5.0 mL
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Part 3: Pycnometric Method:
•Using the smaller of the two metal samples, determine the volume
via your calibrated pycnometer.
•Place the solid in your pycnometer and weight to ± 0.0001g on the
analytical balance.
•Fill the pycnometer with water making sure there are now bubbles
when the stopper is replaced. Record the mass.
Mass Pycnometer + sample + water
- Mass Pycmometer + sample
Mass water surrounding the sample
Mass water
surrounding the
sample
Volume of water
surrounding the
sample
Volume of
sample
Density of
sample
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Mass Pycnometer + sample + water
- Mass Pycmometer + sample
Mass water surrounding the sample
Mass water
surrounding the
sample

Volume of water
surrounding the
sample
using density
Volume of
sample

Subtract the volume of
water from the total
pycnometer volume
Density of
sample

using the sample
mass
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•Goggles on at all times
•Only water goes in the sink, all other waste in the hood
•check out and return the pycnometers from the stock room.
DO NOT LEAVE THEM IN YOUR LOCKER!
• Return the rulers and solid samples to the front of the room.
•Pick up any paper towels and put them in the trash.
•Wipe down any spills on the bench tops.
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