# Chem Lab: Comparing Density Graphs Name: ___________ Hour ```Chem Lab: Comparing Density Graphs
Name: ___________________________ Hour: ________
Purpose: Compare the densities of a variety of materials by observing graphs.
Materials: Triple Beam Balance, Coal, Galena, Rose Quartz, Sulfur, Block of Wood, Graduated Cylinder, Ruler
Pre- Lab Questions:
1. Define the following terms in your own words:
Volume-________________________________________________________________________________
Mass-_________________________________________________________________________________
Density-_______________________________________________________________________________
2. Formula for density is
3. Units:
D=
Volume-__________
Mass-______________
Density-______________
Find the Density:
1. Find the mass of each object using the triple beam balance.
2. Record your findings in the table below. Don’t forget the units.
3. To find the volume of the objects:
a. Put about 50 ml of water in the graduated cylinder AND record the exact amount in the space labeled
“Initial Volume”.
b. Drop the object into the cylinder and record the total mL in the space labeled “Total Volume”. This is the
volume of the water and the volume of the object.
c. Find the difference between Initial and Total. Record in the column marked “Volume.”
Object
Mass
(Object)
Initial
Volume
(water)
Total
(water +
object)
Volume
(object)
Solve for Density
Coal
(black)
Galena
(silver)
Rose quartz
(pink)
Sulfur
(yellow)
Question:
1. Why didn’t use the formula, volume=length X width X height, to find the volume of the above objects?
_____________________________________________________
More on back!
Chem Lab: Comparing Density Graphs
Name: ___________________________ Hour: ________
Density of a Block of Wood:
Find the mass, volume and density of wood. Show your work and include units.
Mass= ________ units: ______
Volume=_______ units: ______
Density= _______ units: ______
1. Considering your work above, why does wood float on water? Hint: Think about the Density of Water lab.
2. Consider the graph to the right:
a. What is the independent
variable?
b. What is the dependent variable?
c.
What does the slope of this
graph represent?
d. Which of the three elements in
the graph has the greatest
density?
e. Which of the three elements has
the smallest density?
3. Imagine you made a graph similar to the one above for the four substances in the first part of the lab (coal,
galena, rose quartz, sulfur). List them in order from the substance with the steepest slope to the substance with
the least steep slope:
4. Directly proportional means that as one value increases, the other value also increases. Inversely proportional
means that as one value increases, the other value decreases. Do mass and volume appear to have a direct or
an indirect relationship?
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