Chapter 2: Measurement and Problem Solving
Date:____________
Section 5: Density - Notes
Objectives:
 Calculate the density of a substance.
 Use density as a conversion factor.
Density:
 The density of a substance is the ratio of its mass to its volume.
o
Density =
or
d=

Measuring mass: use a ________________________

Measuring volume:

o
___________________________ (l x w x h) (πr2h)
o
_____________________________________________ (Vf-Vi)
Units of density:
o
Solid substance = _____________
o
Liquid substance = _____________

Example: A sample of liquid has a volume of 22.5 mL and a mass of 27.2 g.

m=

V=

Example: For a liquid substance with a density of 1.32 g/cm3, what volume should be measured
to deliver a mass of 68.4 g?

Example: A steel cylinder has a volume of 246 cm3 and a density of 7.93 g/cm3. What is its mass
in kilograms?

Density is an ________________________ property
o
It does ____________________________, no matter
the size of a sample


1 kg of gold has the same density as 1 g, or 1
lb, or 1000 kg, etc.
Every substance has a ________________________________
o
you can _______________________ an unknown
substance by calculating its density and comparing it
to known values
Temperature and Density:

Density changes with __________________________________
o
For most substances, an ____________________ in temperature results in a
__________________ in density

As temperature increases, molecules move further apart. This increases the
______________________ of the substance while the ____________ remains
the same – thereby decreasing the density.

So ________________ are generally more dense than __________________,
which are more dense than __________________.
Density of Water:


The density of liquid water is ___________ g/mL
o
Anything more dense than water will ______________
o
Anything less dense than water will _______________
Water is one of a unique group of substances that is actually less dense as a solid than a liquid
o
Ice __________________ in water!
Practice:
1. A jeweler offers to sell a ring to a woman and tells her that it is made of platinum. Noting that
the ring feels a little light, the woman decides to perform a test to determine the ring’s density.
She places the ring on a balance and finds that it has a mass of 5.84 g. She also finds that the
ring displaces 0.556 cm3 of water. Is the ring made of platinum?
2. The woman takes the ring back to the jewelry shop, where she is met with endless apologies.
The jeweler had accidentally made the ring out of silver rather than platinum. The jeweler gives
her a new ring that she promises is platinum. This time when the customer checks the density,
she finds the mass of the ring to be 9.67 g and its volume to be 0.452 cm3. Is this ring genuine?