Index Of / Teacher Mpeg What Is The Effect Of A Liquids Temperature On Its Index Of Refraction?

What is the effect of a liquids temperature on its index of refraction? - index of / teacher mpeg

I thought doing this for my scientific experiment .. That approved by my teacher, but I really do not understand what is the refractive index .. Please can someone explain to me together in English? and I saw that you had to use a refractometer to measure refractive? Where can I .. are too expensive?