Measurement of Refractive Index: The Refractive index of a medium is defined as the ratio of speed of lignt in vacuum to the speed of light in the medium
The refractive index is a dimensionless number.
It describe how light propagates through the medium .
The refractive index determines how much light is bent or refracted, when entering a medium.
The refractive index measurement are reported in the literature at 20OC or 25 OC .
Dependence of Refractive Index on Temperature:
As the temperature increases, density of liquid medium decreases. It means that liquid becomes less dense with increasing temperature .Since the liquid is less dense, the speed of light through it increases or light travels through it faster. As a result of this ,the refractive index decreases since it is inversely proportional to the speed of light through the liquid. Thus the refractive index of liquid or solution decreases with increasing temperature.
Dependence of Refractive Index on Concentration: As the concentration of solution increases, density of liquid medium increases. It means that liquid becomes more dense with increasing temperature .Since the liquid is more dense, the speed of light through it decreases. As a result of this ,the refractive index increases since it is inversely proportional to the speed of light through the liquid. Thus the refractive index of liquid or solution increases with increasing concentration.