Practice calculating densities from experimental data.
Practice calculating and interpreting percent error for data.
Practice showing work for calculations in chemistry.
Reflect on the experiment that was performed.
Procedure:
For your post-lab work, please address the following questions for each part of the experiment.
Format and submission options:
Write this information on paper, take a picture, then upload onto this assignment page as a pdf. OR
Type the information and then upload onto this assignment page as a pdf. OR
Write this information on paper or type the information and then submit it in person at class on the due date.
Lab activity 2 is now complete and there is no other required material to submit for Lab Activity 2.
Questions for Part A:
1. For each instrument that you evaluated in lab for Part A, choose a value from the list of possible readings provided that could be read using the instrument
. Hints: Not all options on the list will be used. Even though there may be more than one correct answer for a given instrument, please choose only one to
write on each line. A value should be used only once.
Beaker ________
Buret ________
Graduated Cylinder ________
Graduated Pipet ________
Thermometer ________
List of possible readings: 500. mL, 110.33 mL, 80.1 mL, 75 mL, 60.23 mL, 45.01 mL, 30.9 mL, 20.0 mL, 8 mL, 0.36 mL, 401.2 oC, 205 oC, 89.3oC, 45.02 oC, 18
oC.
2. In two to five sentences, explain what criteria you used to make these decisions. Keep your explanation universal so that it can apply to all of the
instruments.
3. What was the most challenging aspect of this part of the experiment for you?
Questions for Part B:
1. Calculate the density of the unknown liquid. Show all of your work in the proper format, as shown in the sample lab notebook pages.
2. Using the accepted value for your unknown liquid from the following list, calculate the percent error for your density of the unknown liquid.
Solution A, C, F = 1.0490 g/mL
Solution B, D, E = 1.0064 g/mL
3. Create a table, with a table number and title, that includes your unknown liquid number, your calculated density for your unknown liquid, the accepted value
for your unknown liquid, and the percent error for the density of the unknown liquid.
4. Was your calculated density higher or lower than the accepted value? Indicate one possible experimental reason for this. Your reason should not be a
calculation error as that can be fixed at home. Your reason needs to be specific to this experiment.
5. If you were going to repeat this part of the experiment in the future, what would you do differently to improve the results?
Questions for Part C:
1. Calculate the density of the unknown metal. Show all of your work in the proper format, as shown in the sample lab notebook pages.
2. Using the accepted value for your unknown metal from the following list, calculate the percent error for your density of the unknown metal.
Metal 1 = Aluminum = 2.70 g/mL
Metal 2 = Zinc = 7.14 g/mL
Metal 3 = Lead = 10.83 g/mL
3. Create a table, with a table number and title, that includes your unknown metal number, your calculated density for the unknown metal, the accepted value
for your unknown metal, and the percent error for the density of the unknown metal.
4. Was your calculated density higher or lower than the accepted value? Indicate one possible experimental reason for this. Your reason should not be a
calculation error as that can be fixed at home. Your reason needs to be specific to this experiment.
5. If you were going to repeat this part of the experiment in the future, what would you do differently to improve the results?
