Precision and Accuracy Lab Report
Precision describes the closeness of results that have been obtained in exactly the same way while accuracy indicates the closeness of the measurement to its true value. This experiment was used to determine the accuracy and precision of different volumetric measuring devices, as well as determining the density of an unknown metal. This lab was to help understand the application to volumetric measurements.
Part 1: First, the next-to-smallest beaker was cleaned, dried, and weighed on the scale where it’s mass was determined. The container was then tared so the scale would only read the mass of the water. The smallest beaker was used to measure out 14 mL of water. Then, that waster was poured into the pre-weighed beaker and put on the scale. Once the measurement was recorded the beakers were both cleaned and dried. This process was repeated two more times. Second, a 100 mL graduated cylinder was used to measure out 14 mL of water. Then, that water was poured into the pre-weighed beaker and put on the scale. Once the measurement was recorded, the beaker and graduated cylinder were both cleaned and dried. This process was repeated two more times. Third, a 25 mL buret was used to measure out 14 mL of water. Then, that water was poured into the pre-weighed beaker and put on the scale. Once the measurement was recorded, the beaker and buret were both cleaned and dried. This process was repeated two more times. After recording the mass using three different volumetric devices, each with three trials, density was calculated for each volumetric device and trial. Then, the trials were averaged. This concluded that the buret was the most accurate measuring device. Last, the average mass of water and standard deviation was calculated, confirming the results that the buret was the most accurate measuring device.
Results/Data:
Table 1: Mass of 14 mL of water in different volumetric devices
Volumetric Device | Mass (g) | | Measurement 1 | Measurement 2 |
Part 1: First, the next-to-smallest beaker was cleaned, dried, and weighed on the scale where it’s mass was determined. The container was then tared so the scale would only read the mass of the water. The smallest beaker was used to measure out 14 mL of water. Then, that waster was poured into the pre-weighed beaker and put on the scale. Once the measurement was recorded the beakers were both cleaned and dried. This process was repeated two more times. Second, a 100 mL graduated cylinder was used to measure out 14 mL of water. Then, that water was poured into the pre-weighed beaker and put on the scale. Once the measurement was recorded, the beaker and graduated cylinder were both cleaned and dried. This process was repeated two more times. Third, a 25 mL buret was used to measure out 14 mL of water. Then, that water was poured into the pre-weighed beaker and put on the scale. Once the measurement was recorded, the beaker and buret were both cleaned and dried. This process was repeated two more times. After recording the mass using three different volumetric devices, each with three trials, density was calculated for each volumetric device and trial. Then, the trials were averaged. This concluded that the buret was the most accurate measuring device. Last, the average mass of water and standard deviation was calculated, confirming the results that the buret was the most accurate measuring device.
Results/Data:
Table 1: Mass of 14 mL of water in different volumetric devices
Volumetric Device | Mass (g) | | Measurement 1 | Measurement 2 |