Density Lab
Introduction
Density is in intensive property. An intensive property is a property of matter that is independent of the quantity of the substance. For example, the density of one single drop of water is exactly the same as the density of a liter of water.
Both mass and volume are a function of the amount of material present (extensive property). Density is the ratio of mass to volume: d=m/V
Density is a useful way to characterize a substance because each substance has a unique density.
Metric units of density are typically (but not limited to): g/mL, g/cm
3
, g/cc.
Goal:
In the balance lab you learned how to measure the mass of items. In this lab you will measure the volume of irregular shapes solids (irregular shape assumed) by volumetric displacement technique. The mass will be given for each sample. Collected data will be used to report density for the measured items.

Density Lab
Procedure
**NOTE: Use instructions provide by the instructor – DO NOT USE INSTRUCTIONS
IN CHEMLAB! To remove the instructions on the screen, and free-up more working area, perform the following operation: click on the OPTIONS tab; then click on LAB
ONLY. The instructions “disappear” and all of the area is now lab space.**
Measurement of Volume:
The volume of an irregularly shaped object can be determined by measuring the volume of water it displaces when completely submerged.
Step 1: Obtain a 10 mL graduated cylinder from the equipment menu. Fill graduated cylinder with 5 mL of water and record volume (Initial Volume = V
I
).
Step 2: Obtain 10g sample of your choice and place in cylinder. Record new volume to
0.1 decimal place (Final Volume = V
F
). Note the graduations on the cylinder are 0.2 mL increments.
Step 3: Repeat volume measurements for remainder of samples.

Density Lab
Observations
Data
Mass (g): (given)
Al: 10.g (given)
Au: 10.g (given)
Pb: 10.g (given)
Unknown #1: 10.g (given)
Unknown #2: 10.g (given)
Volume (mL): (report correct significant figures)
Al:

V
I
= ____________mL

V
F
= ____________mL
{Volume Al = V
F
- V
I
}
Volume Al:____________mL
Au:

V
I
= ____________mL

V
F
= ____________mL
{Volume Au = V
F
- V
I
}
Volume Au:____________mL
Pb:

V
I
= ____________mL

V
F
= ____________mL
{Volume Pb = V
F
- V
I
}
Volume Pb:____________mL
Unknown #1:

V
I
= ____________mL

V
F
= ____________mL
{Volume Unknown #1 = V
F
- V
I
}
Volume Unknown #1:____________mL

Unknown #2:

V
I
= ____________mL

V
F
= ____________mL
{Volume Unknown #2 = V
F
- V
I
}
Volume Unknown #2:____________mL
Density (g/ml):
Using the formula d=m/V, calculate the density for the samples. (report correct significant figures). Show an example calculation – remember units!

Al:____________g/mL

Au:____________g/mL

Pb:____________ g/mL
Calculate unknown densities. Compare your unknown densities with the known samples from above. Report your unknown sample:

Unknown #1:____________ g/mL – Identification, circle one (Al, Au, Pb)

Unknown #2:____________ g/ mL – Identification, circle one (Al, Au, Pb)
Questions
1) The reported density for Au is 19.3 g/cc and Pb is 11.3 g/cc. Why do you think your measured results are slightly different from these values?
2) Calculate the density of a 3.00 X 10
2
g object that has a volume of 50.0 mL.
3) What is the mass, in grams, of a piece of iron that has a volume of 1.50 X 10
2
mL and a density of 7.20 g/mL.

Discussion