How and why does temperature affect the refractive index of a liquid?

Answer 1

Yes, the refractive index of a liquid often is different at different

temperatures

(usually negative; e.g. It goes down as temperature goes up), although

typically the effect is very nominal.

However, that is not to say that there is a constant relationship between Ref index

& temperature. Refractive index is proportional to the square roots of

electrical permittivity and magnetic permeability. These factors may change

with temperature, but not linearly, and therefore RI does not have a simple

relationship with temperature.

Answer 2

Temperature affects the refractive index of a liquid by changing the density of the liquid, which in turn alters the speed of light passing through it. As the temperature increases, the density of the liquid decreases, resulting in a lower refractive index. This change in refractive index can impact the way light travels through the liquid and how it is bent or refracted.