How to Measure the Density of Water

The density of water is dependent upon what is dissolved in the water.

Density is the measure of mass per unit volume. It is present in a large portion of our lives, whether in buoyancy or salad dressing. When two substances of different densities are combined, the less dense substance will float on top of the more dense substance. The density of pure water is, by definition, 1 gram per cubic centimeter. Water with substances dissolved in it, like salt water or lake water, will have a higher density.

Things You'll Need

• 10 milliliter graduated cylinder
• Balance
• Water

Instructions

1. Place the graduated cylinder on the balance and tare the balance. If the balance does not have a tare function, write down the mass of the graduated cylinder.

2. Remove the graduated cylinder and add exactly 1 milliliter of water to it.

3. Set the graduate cylinder with 1 ml of water on the balance and read the mass. If the balance was tared, the mass is equal to the density of the water. If you wrote down the mass of the graduated cylinder, subtract the mass of the graduated cylinder from the mass displayed to get the mass of the water, which is equal to the density of the water.

Tips & Warnings

• Note that 1 cubic centimeter is equal to 1 milliliter.

References

• "Fundamentals of Chemistry"; Second Edition, 1998, David Goldberg