Density Lab
Introduction: Density is the ratio of an object's mass to its volume. Gold has a density of
19, the average rock has a density of 3, and water has a density of 1 g/mL. 1 g/mL means
that 1 mL (or cm3) of water has a mass of 1 gram or 1 Liter of water has a mass of 1 kg.
You will be finding the density of a liquid and two solids. The masses will be found on a
balance. The volumes will be calculated from the radius and the height or determined by
submerging in water.
Don't forget when reading the graduated cylinder to read the bottom of the meniscus as
shown below.
Pre-lab questions:
1. Which is more dense, a marshmallow or hot chocolate?
a) It depends on how much you have
b) The marshmallow because it floats
c) The hot chocolate because it is a liquid
d) The marshmallow because it weighs 25g and the chocolate powder only 17 g
2. Which is more dense, water or oil?
3. What mass do 3.0 mL of gold have?
Procedure: (Liquid)- Place a 10 mL graduated cylinder on the balance and record its
mass. Put exactly 10 mL of the unknown liquid into the cylinder and find its mass again.
Record your data in your data chart.
Solid (regular shape)- Use a caliper to measure the height and diameter of the cylinder.
Use V=pr2h to find the volume of the object. Record your data in your data chart.
Solids (irregular shape)- Put approximately 50 mL of water into a 100 mL graduated
cylinder and record the exact amount in your data table. Gently place the object into the
cylinder and record the new volume. Place the object on the balance and record its mass
in your data table.
Data:
Liquid:
Mass of empty cylinder ___________ g
Mass of cylinder and unknown liquid ____________ g
Mass of liquid ____________ g
Solid (regular shape):
Cylinder height ____________ cm
Cylinder diameter ____________ cm
Cylinder radius _____________ cm
Cylinder volume _____________ cm3
Cylinder mass _____________ g
Solid (irregular shape):
Original volume ____________ mL
Volume w/ object _____________ mL
Volume of object _____________ mL
Mass of object ____________ g
Calculations:
1. Calculate the density of the liquid. Show your work.
2. Calculate the volume and the density of the metal cylinder. Show your work
3. Calculate the volume and the density of the irregular object.
Post-Lab Questions:
1. What would be the mass of 100cm3 of the metal that the cylinder is made of?
2. Find a chart of the densities of common metals and figure out what metal it is.
3. If oil has a density of .88 g/cm3, would it float on the liquid used in this lab?
4. Since a balance is much more accurate than a graduated cylinder, densities are found
differently when an accurate answer is needed. A cylinder full of water is put on the
balance and then the object is put in, allowing some of the liquid to spill out. Then the
cylinder, object, and water (minus the spill-over) are weighed. The volume of the object
is then calculated accurately. Use the following data to find the density of the unknown.
Assume that the density of water is 1.000 g/cm3.
Mass of cylinder full of water 201.051 grams
Mass of object 15.211 grams
Mass of object, cylinder and water (minus spill-over) 212.219 grams
Density of object (be sure to use the correct number of significant figures and show your
work) __________