DENSITY :-
Density of a substance is defined as mass per unit volume.
Mathematically , it is written as :
Density = Mass / Volume
SI unit – kgm-3
CGS unit- gcm-3 RELATIVE DENSITY :-
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. Another term used for relative density is specific gravity.
Relative Density (RD) = Density of the substance / Density of water at 4°C
Relative density is a ratio of the same physical quantities, it has no unit.
The relative density of a substance can also be defined as the ratio of the mass of a certain volume of a substance to the mass of the same volume of water at 4°C.
Relative Density (RD) = Density of the substance / Density of water at 4°C
Density = Mass / Volume for equal volumes of a substance and water,
⸫ RD = mass of the substance / volume of the substance / mass of waterat 4°C / volume of water
⸫ RD = mass of the substance / mass of water at 4°C RELATION BETWEEN DENSITY AND RELATIVE DENSITY :- Density = Relative density x 1 gcm-3
Density = Relative density x 1000 kgm-3