Measurement (adapted from Flinn ChemTopicLabs) 2
Name _____________________________________________
Experiment Data Sheet
Show your work!!Please take note that the measurements here are different from the video. Perform all calculations based on the measurements listed on this packet in red. The measurements were obtained as shown in the video.
Table 1.
| 50 mL BEAKER | Trial 1 | Trial 2 |
| Exact volume of water from beaker | ||
| Mass of dry beaker | ||
| Mass of beaker plus water sample | ||
| Mass of water sample *subtract* |
1. Using the data from Table 1, calculate the density of water as measured using the beaker from Trial 1 and Trial 2. (Since this is not you final answer, you can round to four decimal places.)(1pt)
2. For the beaker, calculate the average density of water. Report your average with the correct significant figures from your measured values of mass and volume.(1pt)
Table 2.
| 50 mL cylinder | Trial 1 | Trial 2 |
| Exact volume of water from cylinder | ||
| Mass of dry cylinder | ||
| Mass of cylinder plus water sample | ||
| Mass of water sample *subtract* |
3. Using the data from Table 2, calculate the density of water as measured using the graduated cylinder from Trial 1 and Trial 2. (Since this is not you final answer, you can round to four decimal places.)(1pt)
4. For the graduated cylinder, calculate the average density of water. Report your average with the correct significant figures from your measured values of mass and volume.(1pt)
Table 3.
| 20 mL pipette | Trial 1 | Trial 2 |
| Exact volume of water from pipette | ||
| Mass of dry beaker | ||
| Mass of beaker plus water sample | ||
| Mass of water sample *subtract* |
5. Using the data from Table 3, calculate the density of water as measured using the volumetric pipette from Trial 1 and Trial 2. (Since this is not you final answer, you can round to four decimal places.) (1pt)
6. For the pipette, calculate the average density of water. Report your average with the correct significant figures from your measured values of mass and volume. (1pt)
7. Use the average density, along with the accepted density of water from table 4 to calculate the percent error for each piece of glassware. Round each percent with three significant figures. (2pts)
Post Lab Q&A
1. Which piece of glassware (the 50 mL beaker, 20 mL volumetric pipette or 50 mL graduated cylinder) did you found to be the most accurate? Justify why that piece of glassware is the most accurate using your data from the experiment.(2 pts)
2. Which piece of glassware (the 50 mL beaker, 20 mL volumetric pipette or 50 mL graduated cylinder) did you found to be the most precise? Justify why that piece of glassware is the most precise using your data from the experiment.(2 pts)
3. Would your measured density increase, decrease, or stay the same: You correctly measured the mass of your water sample, but before reading the volume you spilled some of the sample onto the bench? Why? (1 pts)
4. Which piece of glassware would you choose to use if your procedure asked you prepare a sample of water that is 10 mL for a reaction? The measurement needs to be fairly accurate and also needs to be done quickly. Why? (1 pts)
