density lab project

Swamy Florida International University

CHM 1020L

Density

This lab uses the following simulation

https://www.pbslearningmedia.org/resource/arct15-sci-densitylab/density-lab/

If the link does not work for you it can also be accessed using the following link

https://www.simbucket.com/simulation/density-lab/

Learning objectives

1) Understand the concept of density

2) Relate the value of density of a substance to the physical characteristics of the substance.

3) Predict the effect of volume on density of pure substances

4) Predict the effect of mass on density of pure substances

5) Organize a given list of substances from least dense to most dense with supporting evidence.

6) Apply knowledge gained in the experiment to explain relevant real-world situations.

7) Apply knowledge gained in the experiment to create a density gradient column.

Cite your sources for each answer at the very end of the document even if you think something is common knowledge – a video/ a website etc.

1) What is the density of water generally and how do you know this?

2) In the experiment what precautions must you take to ensure that your experiment gives you the correct results?

3) In real life can you move an object out of water, onto a balance and expect to get the correct mass of the object? Why or why not? Please explain.

Observations and Post-Lab questions

Table 1

Effect of changing mass and volume on density (Don’t forget the units)

Observation number	Mass in	Final volume (Vf)	Initial volume (Vi)	Change in volume (V) = Final volume (Vf) – initial volume (Vi)	Mass/V (Do the calculation and plug in the number) Units?
1
2
3
4
5
6

1) Average values (Add all six values of mass/V calculated above and divide by the number 6)

2) Make a scatter plot with mass on the Y axis and change in volume on the X axis. Add a straight line and show the slope on the line. Have the line pass through the origin.

3) Is there any correlation between the slope of the line in the graph and the average you previously calculated?

4) What effect does changing the mass of the solid cube in the container have on the density of the material? Explain your reasoning as to why this effect is seen?

5) What effect does an changing the volume of the liquid in the container have on the density of the material? Explain your reasoning as to why this effect is seen?

6) In your own words, define density.

Table 2

Effect of changing fluid on density (don’t forget the units)

Obs #	Fluid density	Mass in	Final volume (Vf)	Initial volume (Vi)	Change in volume (V) = Final volume (Vf) – initial volume (Vi)	Mass/V (Do the calculation and plug in the number) Units?
1	1 some other liquid (fluid density = 2.5 g/mL)
2	water (fluid density = 2.5 g/mL)

5) Does changing the density of the fluid being used to measure the volume change to determine the density of the solid block make a difference? Explain your reasoning!

Table 3

Examining different materials (don’t forget the units)

	Material being used	How does the material behave when immersed in water	Mass	Final volume (Vf)	Initial volume (Vi)	Change in volume (V) = Final volume (Vf) – initial volume (Vi)
1	unknown
2
3
4
5
6
7

1) Speculate on the identity of the unknown material and clearly explain how you came to this conclusion showing all your calculations (maybe you can use a table to explain the calculations).

2) When you were testing these materials did groups of materials behave compared to another group? Please explain in detail what you observed and your reasoning behind separating the materials into these two groups?

3) Arrange all the materials in the panel (except the unknown) from highest to lowest density.

4) I want you to pay particular attention to the way ice behaves in this simulation. What did you notice about how ice behaves?

5) How did this property of ice contribute to the Titanic disaster?

6) This same property of ice allows marine life to exist in Antarctica during the winter. Explain how this is possible.

7) The relationship between solid ice and liquid water is special because there is something unique with respect to density. What is that?

Sources used: Cite your sources below