Water has an easy way to remember it's mass. Water is 1 gram per
milliliter (mL). To get it's mass for other sizes, you just need to
figure out how many mL's there are in what you're looking for.
In this case, we want the mass of water in a gallon. There are
3785.4 mL per gallon. That means that a gallon of water is 3785.4 grams
or 3.7854 kg.
If you're more into the US measurement system. 3.7854 kg is about 8.4 pounds.
Adam
(published on 10/22/2007)
