Density Lab Pre-Lab Name Period 1. Define density. 2. If a substance has a density of 8.56 g/cm3, will the substance float or sink in water? Explain. 3. A cylindrical substance was examined and the following data collected using a metric ruler and a centigram balance: Diameter (cm) 2.30 Height (cm) 7.20 Mass (g) 210.40 a. Calculate the volume of the cylinder, given the equation for the volume of a cylinder is: 𝑉 = 𝜋( 𝐷𝑖𝑎𝑚𝑒𝑡𝑒𝑟 2 2 ) ∙ 𝐻𝑒𝑖𝑔ℎ𝑡 b. Calculate the substance’s density. c. The substance is determined to be zinc, with a density of 7.14 g/cm3. Calculate the percent error of the experimental density, given the equation for percent error is: %𝐸𝑟𝑟𝑜𝑟 = ( |𝐴𝑐𝑡𝑢𝑎𝑙−𝐴𝑐𝑐𝑒𝑝𝑡𝑒𝑑| 𝐴𝑐𝑐𝑒𝑝𝑡𝑒𝑑 𝑉𝑎𝑙𝑢𝑒 ) 𝑥100 4. A student team determined the density of a liquid three different times. The values were determined to be 2.84 g/mL, 2.85 g/mL, and 2.80 g/mL. The accepted density value is 1.3 g/mL. Are the values accurate? Are they precise? Explain your answers. 5. Graph the following information using excel. Plot a graph of mass (y-axis) versus volume (x-axis). Include a best fit straight line through the points. Print your graph and staple it to the back of this worksheet. Sample 1 2 3 4 5 Mass (g) 34.00 18.02 77.05 98.63 55.34 Volume (cm3) 4.74 2.49 10.8 13.9 7.70 a. Using 2 points from the line of best fit, calculate the slope of the line of best fit. Show your work and include units with your calculation. b. What is the equation for the line? c. What does the slope of the line represent (think rise over run)? 6. You will need to come prepared to collect data for your formal lab the next time we have class. Read the information sheet about the lab. In the space below, write a rough draft of a procedure and data table that will be appropriate for the data you need to collect.