Density

Density is a measure of how much mass does a substance have compared to it volume. The relationship is

Density = mass / volume

The density of liquid is usually reported in units of g/mL. The density of a solid is reported as g/cm³.

Procedure:

A. Density of alcohol

Weight a clean and dry 10 mL graduated cylinder. Record the mass.

Mass of graduated cylinder: ______________

Remove the graduated cylinder from the balance. Pour 5 to 6 mL of an alcohol solution into the graduated cylinder. Read the volume carefully.

Volume of alcohol: ___________________

Weight the graduated cylinder containing alcohol and record the results.

Mass of graduated cylinder and alcohol: __________________

Mass of alcohol = Mass of graduated cylinder and alcohol – mass of empty graduated cylinder

Calculate the density from weight and volume.

Density: __________________

B. Density of a rubber stopper

Obtain a rubber stopper and weigh it on a balance. Record the mass.

Mass of rubber stopper: _____________________

Add approximately 50-60 ml of water to a 100 mL graduated cylinder and read the volume carefully.

Volume of water in graduated cylinder: ________________

Drop the rubber stopper into the graduated cylinder and read the resulting volume

Volume of water and rubber stopper: _________________

Volume of rubber stopper = Volume of water with rubber stopper – volume of water without rubber stopper

Divide the mass of the rubber stopper by its volume to obtain density

Density of rubber stopper: ________________

C. Density of an unknown metal

Obtain an unknown metal sample and record its identity.

Make sure the metal is dry and weigh the metal on an electric balance.

Mass of the metal cylinder: ______________________

Add 50-60 mL of water to a 100 mL graduated cylinder and read the volume carefully.

Volume of water in graduated cylinder: ___________________

Drop the metal into graduated cylinder and read the final volume carefully.

Volume of water and metal cylinder: _________________

Volume of metal = Volume of water with metal – volume of water without metal

Volume of Metal: _____________________

Calculate the density of the metal by dividing the weight of metal by the volume.

Density of metal: __________________

Which substance has the lowest density? _________________________

Which substance has the highest density? ____________________________