Partners: Betty Alcaraz Date: 9/10/13
Teacher: Wright Class: 7th period
Introduction/Purpose: To determine the densities of unknown substances.
Pre-Lab:
1. Which is heavier, a pound of feathers or a pound of lead? a. A pound of lead. 2. What is the density of a mineral if 427 g of the mineral occupy a volume of 35.0cm3? b. 12.2g/cm3 3. The water level in a graduated cylinder stands at 20.0 mL before and at 26.2 mL after a 16.74 g metal sample is lowered into the cylinder. What is the density of the sample? c. 1.2 g/mL
Safety: Used goggles.
Materials: Triple Beam Balancer, Water, Beaker instead of graduated cylinder, solid metal block, and goggles. Procedures: | Observations | 1. Measure Mass using Triple Beam Balance | | 2. Measure Volume by using water displacement method. Fill a 50 mL graduated cylinder about half full with water, measure the volume, and record volume of water alone in Data Table 1. Measure the volume and record the measurement as “volume of water+sample” IN Data Table 1. Find the “volume of the solid” subtract volume of the “water alone” from the “volume of water+sample”. | When the block was placed into the water, it rised. | 3. Determine Density. Use the mass and the volume of the solid to determine the density. | |
Data Analysis & Results:
Data Table 1: Individual Data and Calculations | Sample B | Mass (g) | 22 g | Volume of water alone (mL) | 50 mL | Volume of water+sample (mL) | 100 mL | Volume of sample (mL) | 50 mL | Density of Sample (g/mL) | 2.2 g/mL |
Data Table 2: Class Data: Mass and Volume of Samples | Sample A | Lab Group | Mass (g) | Volume (mL) | A | 11.2 g | 200 mL | B | 22 g | 50 mL | C | 137 g | 25 mL | D | 127.2 g | 20 mL | E | 16 g | 210 mL | F | 43.5 g | 30 mL | G | 18.5 g | 20 mL |
Conclusion/Error: The purpose of this lab was to find the different densities within the blocks that were