Question

State some of the practical applications of relative density.

Answer 1

1. The concept of relative density is used to compare the densities of materials.
2. The relative density is also known as specific gravity.
3. The relative density of a substance is defined as the ratio of the density of the substance to the density of water at 4°C.
   $Relativedensity\left(RD\right)=\frac{Densityofasubs\tan ce}{Densityofwaterat4°C}$
4. When the volume of the substances is equal to the volume of water,
   $Relativedensity\left(RD\right)=\frac{Massofthesubs\tan ce}{Massofwaterat4°C}$
5. Thus, the relative density of a substance may also be defined as the ratio of the mass of any volume of the substance to the mass of the same volume of water at 4°C.
6. Since relative density is the ratio of two same quantities, it is a dimensionless quantity.
7. Some of the practical applications of relative density are,
   1. It is used for determining the density of an unknown substance from the known density of another substance.
   2. We can use the idea of relative density to test the purity of a given sample.
   3. It is used by geologists to find out the mineral content of the rocks.
   4. It can also be used to identify unknown samples.

Thus, the concept of relative density is used to compare the densities of materials.