Science experiment- having problems with measurements?

Question

for my science project, i am figuring out which substance will be the most effective in absorbing oil spills. i plan to pour oil through the absorbing substance (sand, wood chips, etc.) and measuring the amount of oil that was not absorbed.

if we pour 50 mL of motor oil over the different substances, how much of each substance should we use? i thought we should use 100 grams of each, but wont there have to be more woodchips than sand to equal 100 grams?

what i mean to say is, how should we measure so there is an equal amount of each substance using the metric system?

here is a sample of a similar project

http://www.fellowshipch.org/pcasftimothy07.html

Answer 1

Try this idea:

Pour 50mL of motor oil into a small beaker.  Add a standard amount (by weight or volume) of the absorbent material then, after a set period of time (say 15-30 seconds), pour out the unabsorbed oil through a strainer with holes smaller than the bits of absorbent material and measure its volume.  The less the volume of oil, the better the material is at absorbing the oil.

Answer 2

Yes, use the same mass of each substance. You can measure that precisely, whereas the volume of something like wood chips  varies depending on packing. You can do a secondary analysis showing (approximate) absorption per unit volume.