Here's why:
* Weight depends on density: Density is how much mass is packed into a given volume. Water has a different density than oil, gasoline, or mercury.
* Gallon is a unit of volume: A gallon measures how much space a substance occupies, not its weight.
To figure out the weight of a gallon, you need to know the density of the substance it contains.
Example:
* One gallon of water: Weighs about 8.34 pounds (128 ounces).
* One gallon of gasoline: Weighs about 6.3 pounds (96 ounces).
Let me know what substance is in the gallon, and I can calculate its weight!
