MHS AP Chemistry
Determination of Fat Content
In this lab we will determine the mass percent of fat in a specific
food product (TBA in class). There will be only the barest outline
procedure provided; details are up to the students. The class will
turn in one paper to present their results, and share a grade.
A Note About The Solvent
The recommended solvent is cyclohexane, which is volatile, toxic, flammable,
and smelly. We will most likely use an alternative solvent in the
form of paint stripper, which is not quite as volatile, toxic, flammable,
or smelly. There will be no open flames allowed, and as often as
possible the solvent fumes should be contained (in the hood, or a vent
hose, or some other method).
What Should The Paper Include?
Decide ahead of time on what data you will need for your calculations.
Get a sample of the food, smash it to bits, and dissolve the fat part of
it in our solvent of choice.
Separate the solid bits of food from the fat/solvent solution. You
may decant, filter, centrifuge, or use some other method.
Separate the fat from the solvent. You may use low-temperature crystallization,
distillation, low-pressure distillation, evaporation, or some other method.
Dispose of your waste properly and clean up your lab station.
Calculate the mass percent of fat present in your sample, and write a paper
together to present your results. Make sure everybody agrees the
paper is good before it is passed in.
Table of Contents
Introduction Section (partly to establish interest, and partly short formal
research paper to show scientific background)
Procedure(s) - numbered lists, be general but clear
Calculations - each one described and shown, including labels
Results - summarized in a table
Conclusions - Brief discussion of results, validity, and possible further
[MHS AP Chem page]