Density Lab Introduction: Density is an important property since it help identify a substance. Purpose: To determine the type of known metals by comparing densities of the unknown to given density values of known metals. D = m/v Procedure: Determine the mass of the unknown metal by placing it on a Electronic balance. Also, determining the volume of the unknown by using the displacement method. This method is also used for materials of irregular shape.

Experimental methods: Balance should be tared before use. Obtain the metals-at least 2 metal types. (3 different samples) Determine the mass of the metals by weighing them on the balance. Make sure to wipe the metals with a kimwipe to insure accurate wt. Enter values (at least 3 different samples) on your data table. Obtain 100 ml grad cylinder. Add water and note the volume by reading the initial volume at the bottom of the meniscus. 7. Add your weighed unknown metal--read the final displaced volume. Record your initial and final volume in the data table. Repeat for all metals. Subtract the Vmetal = Initial volume – final volume. Determine the mean of the metal wt. Enter into table. Determine the mean of the Vmetal. Enter into table. Calculate the density of the unknown metal.

Data Table 1 2 3 MEAN Calculated density Calculate density Metal 1 MASS (g) VOLUME Initial (mL) VOLUME Final (mL) VOLUME metal 1 (mL) METAL 2 VOLUME Initial(mL) VOLUME Final (mL) VOLUME Metal 2(mL) 1 2 3 MEAN Calculated density Calculate density Standard density

Calculations Calculated density for Cu? Standard density for Cu from the CRC? % error density of Cu = (measured density-CRC value) x 100 CRC Value Calculated density for Zn? Standard density for Zn from the CRC? % error density of Zn = (measured density-CRC value) x 100

Questions Conclusions C: What is the Claim E: What is the Evidence From your % error how close were your results for Cu and Zn? What would contribute to your differences for Cu and Zn? Conclusions C: What is the Claim E: What is the Evidence R: What is your Reasoning