Post-Lab Questions

Directions: Answer each of the following questions. All work must be shown to receive credit for questions involving calculations. All questions are weighted equally.

1. When you transfer water between the beaker and graduated cylinders, did the measured volume change? Provide an example from your personal data set. Why might this be the case?
2. All the graduated cylinders used in this lab can measure small volumes. However, which size graduated cylinder is best for measuring volumes smaller than 10 mL accurately? Explain your reasoning.
3. Consider the class data set from part B of this lab. Does this data set have high or low precision? Justify.
4.  A 25.00 mL volumetric pipet is used to transfer 25.0 mL water to a 25.0 mL graduated cylinder five separate times. Assume 100% of the water is transferred each time. The volume in the graduated cylinder is read to be 24.0 mL, 24.0 mL, 23.9 mL, 24.0 mL, and 24.1 mL. Would you consider the graduated cylinder to be accurate, precise, both, or neither? Justify your answer.
5.  If you were asked to prepare 12.0 mL of a solution as accurately as possible, which instrument(s) & size(s) from this lab would you choose? Why? If you were asked to prepare 120.0 mL instead, which instrument (s) & size(s) from this lab would you choose? Why?