Why does fat dissolve in toluene but water does not when put on a rotary evaporator? any help would be great.thanx

Fat and toluene (taw U een) are both made of non-polar molecules. Since likes dissolve likes, they will mix.

Water is made of polar molecules and will not mix with very well with any non-polar substances.

What is a rotary evaporator? Do you mean a centrifuge?