CHM 130 HBS Measurements Calculations and Properties of Matter Lab Report

CHM130LLLab 2 – Exploring Measurements, Calculations and Properties of Matter
Name: _________________________________________ MEID: ____________________
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Part I: Using Significant Figures in Measurements and Calculations
A. Data Table 1 (4 pts) (Report all values with the correct number of significant figures as well
as the correct metric unit.)
Measurement (units)
Data
(1) Volume of water in 10-mL graduated cylinder (mL)
(2) Volume of water in 50-mL graduated cylinder (mL)
(3) Inside diameter of 50-mL graduated cylinder (cm)
(4) Height of 50-mL graduated cylinder (cm)
B. Follow-Up Questions (Show all calculations with units on each number and the final answer
rounded to the correct significant figures for full credit.)
1. Convert the volumes of the water in the 10-mL and 50-mL graduated cylinders from mL
to L, using the dimensional analysis method. Express your answers using scientific
notation. Show all your work. (4 pts)
2. It is unlikely that your measurements for the volumes of water in the 10-mL and 50-mL
graduated cylinders are identical. Discuss how differences in the level of precision of the
two instruments might have contributed to differences in your measurements. (2 pts)
3. Calculate the volume of the 50mL graduated cylinder using your measurements of
diameter and height and the formula V = πr2h (r=½ diameter). This is your experimental
value. Show all your work. (4 pts)
4. Assuming the accepted value of the volume of the graduated cylinder is 50.00 mL,
calculate the percent error of your volume calculation, using the following formula and
the experimental value calculated in Question 3. Show all your work. (3 pts)
5. It is unlikely that your percent error in Question 4 is 0.00%. Discuss a specific source of
error that could have contributed to the difference between the accepted and
experimental value. Note that “human error” or “calculator error” are unacceptable
reasons. Your reason for error should have something to do with the procedure and/or
measurement. (2 pts)
Part II: Density of Aluminum
A. Data Table 2 (2 pts) (Report all values with the correct number of significant figures.)
Measurement (units)
Data
(5) Initial volume of water in 50-mL graduated cylinder (mL)
10.0 mL
(6) Volume of water and aluminum shot in 50-mL graduated cylinder
(mL)
(7) Mass of aluminum shot (given on outside of packet) (g)
B. Data Table 3 (6 pts) (Report all values with the correct number of significant figures.)
Type of Aluminum
Foil
Mass (g)
Length (cm)
Width (cm)
Volume
(cm3)
Thickness
(cm)
C. Insert the following pictures from Part II with your name and MEID showing in the
photo:
Photo A: Insert a photo of the 50-mL graduated cylinder with 10.0 mL of water AND all of the
aluminum shot from the packet. The graduated cylinder should be positioned to show the
measurement markings on the cylinder and the water’s meniscus. In other words, the
instructor should be able to verify measurement (6) in Data Table 2 by looking at the photo. (6
pts)
Photo B: Insert a photo of the heavy-duty aluminum foil with the ruler positioned along its
width. The ruler should be aligned with the edge of the foil so that the width measurement is
visible to the instructor. The instructor should be able to verify the value in Data Table 3 from
looking at your photo. (6 pts)
D. Follow-Up Questions (Show all calculations with units on each number and the final answer
rounded to the correct significant figures for full credit.)
6. Using water displacement and the information from Data Table 2, calculate the volume
of aluminum shot added to the graduated cylinder. Show all your work. (3 pts)
7. Calculate the experimental value for density of the aluminum shot based on its mass
(given on the outside of the packet) and its volume calculated in Question 6 above. Show
all your work. (4 pts)
8. If the accepted value for the density of aluminum is 2.70 g/mL, calculate the percent
error of your density calculation, using the formula listed above. Show all your work. (3
pts)
9. It is unlikely that your percent error in Question 8 is 0.00%. Discuss a specific source of
error that could have contributed to the difference between the accepted and
experimental value. Note that “human error” or “calculator error” are unacceptable
reasons. Your reason for error should have something to do with the procedure and/or
measurement. (2 pts)
10. Using the accepted value of density from Question 8 and the masses of your two
samples of aluminum foil from Data Table 3, calculate the volume of aluminum in the
regular foil as well as the heavy-duty foil. (Note: You will have to use a bit of algebra and
the formula D = m/V for this calculation!) You must show all your work. (6 pts)
11. Using the values for volume you just calculated for the regular vs. heavy duty samples as
well as your dimensional measurements (length and width in cm) from Data Table 3,
calculate the height, or thickness, of each sample of aluminum using the formula V = l x
w x h. In the formula, V stands for volume, l for length, w for width, and h for height.
Once again, you will have to use your algebraic skills to manipulate the formula to solve
for height. You must show all your work. (6 pts)
12. How much thicker is the heavy-duty aluminum foil than the regular aluminum foil?
Calculate this by dividing the larger thickness by the smaller thickness. This will give you
a value that shows what percentage thicker the heavy-duty foil is than the regular foil.
Express your answer as a percent. [Hint: Here’s an example. Let’s say that you divide
your larger value by your smaller value and get 1.75. This means that the larger value is
75% larger than the smaller value.] (3 pts)
13. If consumers are paying 1/3 (33%) more for the “heavy duty” type of foil, are they getting
their money’s worth? Use information given in this problem and your answer to
Question 12 to justify your answer. (3 pts)
Part III: Using Physical Properties to Separate a Mixture
A. Insert the following pictures from Part III with your name and MEID showing in the
photo:
Photo C: Insert a photo showing the first step in your separation plan. (3 pts)
Photo D: Insert a photo showing a middle step in your separation plan. (3 pts)
Photo E: Insert a photo showing one of the last steps in your separation plan. (3 pts)
Photo F: Insert a photo showing all four substances in their SEPARATED STATE. In other words,
this should be a photo of your results. The iron filings, sesame seeds, sand and salt should all
be visible simultaneously in the photo. (6 pts)
B. Follow-Up Questions
14. Write out the supplies that you needed to complete your lab procedure for separation.
(3 pts)
15. Write out the steps of your successful procedure, making sure to be thorough and
complete. Your steps should be specific enough to be followed by another student to
reach the same results as you. (9 pts)
16. List the unique physical properties of each component that you exploited as you
performed the separation. (4 pts)