Name ______Date ______Period ______

The Density of liquids

Objective:To learn how to measure the density of liquids, and to determine the

relationship between the mass and the volume of liquids.

Hypothesis:

Write an “If….then….” statement about how varying the mass but keeping the volume of a fluid constant will change its density.

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Materials:

  • Triple-beam balance
  • 50 ml graduated cylinder
  • Water, alcohol, vinegar & saltwater

Procedure:

Part One – Finding the density of water

  1. Find the mass of your graduated cylinder and record in Data Table 1 in the Mass of Cylinder column – fill in the entire column with the same value as your cylinder will not change.
  2. For trial one, fill the cylinder with water to the 20-ml mark.
  3. Record this volume in the appropriate place in your table.
  4. Measure the combined mass of the cylinder and the water and record your measurement in Data Table 1 in grams.
  5. Determine the mass of the water in the cylinder by subtracting the mass of the cylinder from the combined mass of the cylinder and water.
  6. Record the mass of the water in grams in Data Table 1.
  7. Repeat steps 2 – 6 three more times, adding an additional 10 mL of water for each trial.
  8. Record the results of each trial in Data Table 1.
  9. Find the averages for each column in Data Table 1 by adding the four values of each and dividing each sum by four. Record your results in Data Table 1.
  10. Calculate the average density of water by using the average amounts of mass of water and volume of water you calculated and the following formula: Density = Mass (g) ÷ Volume (mL)
  11. Record your answer to the nearest hundredth in Data Table 1.

Part Two – Finding the density of other liquids

  1. Repeat steps 1 – 11 with alcohol, vinegar, and saltwater.
  2. Be sure to rinse the cylinder with water, drain it and dry it carefully with a paper towel before measuring each new liquid.
  3. DO NOT POUR LIQUIDS DOWN THE DRAIN!! When you have finished with each liquid, pour it back in to the appropriately labeled storage bottle.

Actual Densities of Liquids used:

Liquid / Density
Water / 1.0 g/ml
Alcohol / 0.789 g/ml
Vinegar / 1.045 g/ml
Salt Water / 1.25 g/ml

Part Three – Graphing the densities of liquids

  1. Use the graph to create an (X,Y) line graph showing each of the four liquids’ densities (one graph with 4 different lines).
  2. Use your “Volume of Liquid” and “Mass of Liquid” data from the four trials of each liquid to create the four points for each of the liquids. Connect the points to create a line.
  3. Each line should be a different color (you should use the corresponding colors that the liquids were colored in the lab).

Analysis:

  1. Which liquid had the greatest density?What does this tell you about the amount of mass it had for a given volume compared to the liquid with the lowest density?

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  1. Assuming that these liquids will not mix, if you were to pour each of them into one container, list the order in which the liquid layers would form from the bottom to the top.

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  1. Look at the line graph you made. The slope of the line represents the density of the liquid. What does the steepness of the slope tell you about the relative densities of the liquids?

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Conclusion:

The conclusion section needs to have five sentences:

1st sentence: Repeat the objective

2nd sentence: Tell how you achieved the objective.

3rd sentence: State your hypothesis and use your data to explain if it was it correct or not and why.

4th sentence: Share what you learned.

5th sentence: This is a general summary of the lab. It ties into the first sentence of the objective.

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Data Table 1:

Trial / Mass of Cylinder (g) / Volume of Water (ml) / Mass of Cylinder and Water (g) / Mass of Water (g) / Density of Water (g/ml)
1
2
3
4
Average

Data Table 2:

Liquid / Trial / Mass of Cylinder (g) / Volume of Liquid (ml) / Mass of Cylinder and Liquid (g) / Mass of Liquid (g) / Density of Liquid (g/ml)
Alcohol / 1
2
3
4
Average
Salt Water / 1
2
3
4
Average
Vinegar / 1
2
3
4
Average
Density of Liquids
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
Mass (g) / 43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19 / Key
18 / Water
17 / Alcohol
16 / Vinegar
15 / Saltwater
14
15 / 20 / 25 / 30 / 35 / 40 / 45 / 50 / 55 / 60
Volume (mL)