Chem 120, Summer Quarter 2012
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EXPERIMENT 1  DENSITY
POST-LAB REPORT
Make sure to report ALL numbers with correct units and the
proper number of significant figures indicated.
TABLE OF CALCULATIONS (Include the formulas and show all the detailed steps of the calculations).
Part 1  Calibration check of the electronic balances:
Percent error calculations:
Part 2  Density of a Regularly Shaped Object:
Density of the copper colored solid
Part 3  Density of a Irregularly Shaped Object:
Density of the irregularly shaped metal object
Identity of the metal:
Density of the silver colored solid
Chem 120, Summer Quarter 2012
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Part 4  Measuring the density of water:
Trial 1
CONCLUSIONS:
Trial 2
(Discuss in your own words how the experiment objectives were met or not. Use paragraph format and
a new paragraph for each one of the four parts. Do not exceed this page).
Chem 120, Summer Quarter 2012
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ANSWERS TO QUESTIONS:
1.
Explain how you determined the identity of your unknown metal. Be specific.
2.
For the density of your unknown metal, calculate your percent error. Is it
higher or lower than the expected value?
What measurement errors likely contribute to this error? Explain.
3.
Note on measurement error for graduated cylinders: One hundred mL Class B graduated cylinders, such as
the ones used in this lab, usually have an error of ± 0.06 mL. What would be the percent measurement
error you expect in the amount of volume change you report?
Chem 120, Summer Quarter 2012
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Quiz Section No.:
4.
What would be the effect of using a wet beaker for the determination of the density of water? In your
answer, address what this means to your measurement error as well as the effect on your density
calculation.
5.
While determining the density of a liquid, a student left air bubbles trapped in a volumetric pipet. Explain if
this error will lead to a value for the density that will be less or greater than expected.
Staple these pages together with the remaining carbon sheets from
your notebook for this experiment before submitting your report.