Activity 6
WHAT IS DENSITY?
Purpose
The purpose of this activity
is to understand the definition of density, to calculate the density of a
substance, and to understand the difference between extensive and intensive
properties.
Introduction
Density
is defined as the mass of a substance divided by its volume. Any pure substance will have a characteristic
density whether the substance is a solid, liquid, or gas. Density is a function of temperature, but the
dependence is much greater for a liquid than a solid and for a gas than a
liquid. For a gas, density is also
noticeably dependent on atmospheric pressure.
Instructions
You will be given a lump of
clay. Shape the clay into a three
dimensional block and measure its length, width and
height. Record these numbers on the
report sheet, then calculate the volume of the block. Measure the mass of the block on a balance
and calculate the density of the block.
Show all calculations clearly and neatly on the
report sheet.
Cut off a section of the block. Measure the new length, width, height, and
mass. Re-calculate the volume and
density of the block.
Repeat this action two more
times.
Report Sheet
WHAT IS DENSITY?
Trial |
Length (cm) |
Width (cm) |
Height (cm) |
Volume (cm3) |
Mass (g) |
Density (g/cm3) |
1 |
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2 |
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3 |
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4 |
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5 |
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Sample Calculations
Questions
1) Sketch a graph of volume
on the X axis versus mass on the Y axis in the space below.
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2) How can the density of the clay represented
on the graph?
3) Density is an intensive property. Based on the data recorded, what do you think
that means?
4) Mass is an extensive
property. What do you think that means,
and why is mass extensive?
5) Why is it important to
know if a property is extensive or intensive?