Question #1c151

1 Answer
Feb 27, 2016

Weighing similar volumetric amounts of substances will show a difference. If the densities are known, the substances can be identified directly.

Explanation:

Weighing similar volumetric amounts of substances will show a difference. If the densities are known, the substances can be identified directly. If they are not, at least you know that the two substances are not the same thing.

For example, two small blocks of similar-looking metals can be weighed against each other, or simply weighed. The difference in weights for a particular volume will tell you if you have lead, iron, zinc or silver.

Similarly, this is the method used to identify many liquids, and particularly alcohol content in beer and liquors. The amount of liquid displaced by a known volume and mass of a float is converted to a density. That density (for a binary system, e.g. water/alcohol) is proportional to the concentration of the alcohol in the water.