If the liquid is water, there is 8 pounds to a gallon. Pounds is a unit of mass/weight. Gallons is a liquid measure. They do not convert cleanly. The density of the liquid being measured can make a big difference.
8 pounds of water in 1 US gallon
1 gallon of water weighs 8.2 pounds, so 32.8 pounds
80 gallons of water weighs about 668 pounds (about 8.35 pounds per gallon).
5 pounds
63,844.1 pounds.
One US gallon of plain water weighs 8.34 pounds.
4
8.33
705 gallons of water weighs about 5,883.2 pounds.
30 cubic feet of water at 8.34 pounds per US gallon equates to ~1,871.63 pounds of water.
About 8.4 pounds.
About 8.53 pounds.