Density Lab

     

       I.            Objectives: The objectives of this lab are to determine the densities of different objects and liquids.

    II.            Materials & Procedures:

A.    Materials: solid sample, balance, graduated cylinder, water, weighing pan, ethanol

B.     Procedures:

1.Measure the length and diameter of 5 pieces of your sample to the nearest 0.01cm. Record in Table 1. Calculate the volume of each sample and record in Table 1.

2.Measure the mass of each sample and record to the nearest 0.01g. Record in Table 1.

3.Calculate the density of each sample from the data for volume by this method.

4.Measure the volume of the sample using the water displacement method. Record the volumes to the nearest 0.1ml in Table 1.

5.Calculate the density of each sample using the volume measured by the water displacement method.

6.Place your 10ml graduated cylinder on the balance pan and press the tare/zero button. Add ethanol to the cylinder until its ½ to ¾ full. Record the mass in Table 2.

7.Place the cylinder flat on your lab bench and read the volume. Record the volume in Table 2.

8.Pour out the ethanol and repeat steps 6 & 7 five more times using different volumes of ethanol.

9.Pour the ethanol down the drain with plenty of water.

10.                    Calculate the density for each trial

11.                    Clean up!

C.     Safety:

 III.            Analysis:

A.    Data

Table 1- Density of Tecaform

Measurement	Trial 1	Trial 2	Trial 3	Trial 4	Trial 5
Length (cm)
Diameter (cm)
Radius (cm)
Volume (cm3)
Mass (g)
Density (g/cm3)
Vi Water (ml)
Vf Water (ml)
Volume (ml)
Density (g/ml)

 

Table 2- Density of Ethanol

Measurement	Trial 1	Trial 2	Trial 3	Trial 4	Trial 5
Mass of Ethanol (g)
Volume of Ethanol (ml)
Density (g/ml)

 

B.     Percent Error

1.Percent error tecaform regular method. (True Value: 1.40)

2.Percent error tecaform water displacement. (True Value: 1.40)

3.Percent error ethanol. (True Value: 0.789)

C.     Graphs

1.Density of tecaform by measurements. X-axis= volume (cm³) Y-axis= mass (g)

2.Tecaform by water displacement. X-axis= volume (cm³) Y-axis= mass (g)

3.Density of Ethanol. X-axis= volume (cm³) Y-axis= mass (g)

D.    Questions

1.Most students find that their results for the determination of their solid’s densities are worse than their results for the determination of Ethanol’s density. Explain why this is probably true.

2.Does the density of an object depend on its sample size? Explain.

3.The density of an object can be used to help identify a substance. Explain how you could distinguish between two substances that have densities that are very, very close to each other.

4. Is the density a physical or chemical properly of matter? Explain.

5.Could you use the method used to determine the volume of your solid for all solids? Explain.

6.Is density an intensive or extensive property? Explain.

7.Calculate the slope of each line on your graphs. What does the slope represent? Explain.

 IV.            Conclusion: