[ken3009]

what is the effect of, lets say conc h2so4 on oil (grease/fat)? will it destroy it or what?

[fledarmus]

Do you know what the structures of greases and fats are? What functional groups are present? How do these functional groups react with acids?

[ken3009]

well, im very generally speaking. im mostly talking about grease in water and edible fats/oils. whats the most important thing the acid does to it?

[discodermolide]

well, im very generally speaking. im mostly talking about grease in water and edible fats/oils. whats the most important thing the acid does to it?

Are the fats saturated or unsaturated? Do they contain any other functionality that can react with conc. H2SO4?

[fledarmus]

Generally speaking, fats and oils, at least in the kitchen, are triglycerides. You can find a brief description here: http://en.wikipedia.org/wiki/Triglycerides

In water, with a small amount of either acid or base, the most general reaction is hydrolysis of the esters. This generates long chain fatty acids and glycerol.

As Discodermolide pointed out, there are also additional reactions that may occur based on any functional groups present on those fatty acids.