Density Lab – An Intrinsic Property of Matter
(Forensic Science)
Introduction: Density is the ratio of an object's mass to its volume. Gold has a density of 19.3, the average
rock has a density of 3, and water has a density of 1.00 g/mL. 1.00 g/mL means that 1 mL (or cm3) of water has
a mass of 1 gram or 1 Liter of water has a mass of 1 kg.
You will be finding the density of a liquid and an irregular shaped solid. The masses will be found on a balance.
The volumes will be determined by submerging in water.
Don't forget when reading the graduated cylinder to read the bottom of the meniscus as shown below.
D = m/V
Procedure:
Part I: (Liquid)1. Place a 10 mL graduated cylinder on the balance and record its mass.
2. Put exactly 5-7 mL of an unknown liquid into the cylinder and find its mass again.
3. Record your data in your data chart including the exact volume of the liquid you used?
4. Calculate the density of the liquid.
Part II: Solids (Irregular shape) [Volume by displacement]1. Place the irregular shaped object on the electronic balance and record its mass in your data table.
2. Place approximately 5 mL of water into a 10 mL graduated cylinder. Record the exact amount in your data
table.
3. Gently place the object into the cylinder and record the new volume.
4. Calculate the density of the irregular shaped object.
Name:
Data:
Partners:
*ALL WORK, including calculations, MUST BE TYPED*
Part I:
Mass of Graduated Cylinder (Empty/Dry)
Mass of Graduated Cylinder and Liquid
Mass of Liquid
Volume of Liquid
Density of Liquid
g
g
g
mL
g/mL
Part II:
Mass of Object
Initial Volume of Liquid
Final Volume of Liquid and Solid
Volume of Solid
Density of Solid
g
mL
mL
mL
g/mL
Calculations:
Show Density calculations for Part I & II.
1. Part I:
2. Part II:
Post Lab Questions:
Densities of Common Liquid Compounds
Substance
Density – grams/mL
Hexane
0.660
Ethyl Alcohol
0.789
Rubbing Alcohol
0.79
Ice
0.92
Corn oil
0.93
Water
1.00
Sea Water (3%)
1.03
25% Salt water
1.25
1. If olive oil has a density of .88 g/cm3, would it float on the liquid used in this lab? Why or why not?
2. Based upon the Table of Liquid Densities given above, what is the probable identity of the unknown
liquid and why?
3. Calculate the Percent Error for the liquid used in Part I, using the formula below. Show all work.
Express answers to correct number of significant figures.
% Error = (|error|/expected value) x 100